Robinson R44

[STANDTO]

Hey TC. I didn't start the argument, just jumped in and stirred the dust up a bit:p

Se though about the gyros. As far back as 1931 it was a good idea! As you've said before, we are pretty good at wheel reinvention (watch this space for new fangled round one coming out soon) so sure as eggs is eggs, someone will try it again. Mind you, they did with the assistance of Wing Commander Ken when they were trying to find Lord Lucan, so it MUST be due for a revisit.:D

FortyOdd - I don't know if your XO would let me through the door!!. Ask him about an old licensing specialist that moved to fraggle rock about 5 yrs ago.....

And is JK STILL there??

[PANews]

John

Photos... your old man [Happy Birthday to him by the way] in 1967 or do you mean the Norfolk ones from 20 years earlier?

I need to E-mail you direct anyway about an Essendon man [Frank Neale 1895-1979] but reply either way for images.

[Mars]

TC:

In the context of this thread:...as has been stated, single helos are dead in the water, now and forever...the CAA / JAA (EASA) will see to thatAs you previously stated, the issue of police helicopters is not a matter for the JAA/EASA. Nothing has changed on the regulation of single-engine helicopters in the UK since JARs were produced. The UK policy was established well before the advent of the JAA.

In fact within the remit of the JARs, there is no barrier to the operation of singles when a safe-forced-landing (SFL) is possible - and there are extensive alleviations in JARs permitting the operation of singles in places when a SFL is not possible. Additional changes are also being considered to remove the restriction on singles for operations in a non-hostile offshore environment (e.g. helidecks in the GOM) - when a risk analysis indicates that they can operate to a safe standard. We are not seeing the demise of the single-engine helicopter.

This whole thread is predicated upon the notion that a single-engine helicopter could perform all of the functions required by the ASU. If the single cannot perform the whole task then there would have to be a revision of the task profile. Most police units only have a single helicopter - the fact that under specific circumstances an R22 could have done a task is really not the point.

[misterbonkers]

Does anybody have any knowledge of these and a supplier?

[headsethair]

Did a load of research on this. Found one side mount in the USA which the guy said was STC'd. Asked him for more details after he sent me a pic of a 44 flying with this thing bolted to it on the right side - never heard another thing other than he wanted $15,000 for the bag of bits.
Someone in the UK has been trying to get a mount strung across the inside of a 44 - which then slides out the right side for use. But too much vibration feedback to be successful.
A Tyler mount won't work on a 44 nose because there's no structure to bolt it to (unlike 206). The official R44 ENG has a strengthened nose section put in at production - and the battery moved down the tailcone to counterbalance the extra weight on the nose.

There is a 44 ENG coming into the UK soon with all the proper kit on it : www.flyingtv.co.uk

[chopperdr]

sirs: tyler camera indeed does have a left or right side camera mount faa stc.'d for the r44 to carry fsi ultra media or similar size cameras, ask for nelson or george at tyler camera for more info.
dr

[old heliman]

Notice that on the weblink it says " Heli Air. R44s maintained by Heli Air have twice lapped the globe and flown to the North Pole successfully " See they don't mention the one that didn't make the South Pole:D

[headsethair]

Old heliman : Don't forget to watch the new Channel 4 series "Grumpy Old Men".

You're in it, aren't you ?

(Later)
My apologies - it was on tonight on BBC2. And you weren't in it. Even you aren't as miserable and grumpy as the line-up for this terrible series. :ugh: Or should that be :*

[alpinehelicopter]

As a FI working for a school operating at altitudes from 3000 up to 12000 feet I'm interested if somebody has made any experiences with the R44 Raven II at altitude?

Thank you?

[Happy Landing !]

I have...

Well sort of:rolleyes:

Not as high as 12k yet, but 6 - 8k in OAT of 25, the Raven II performs very well. This August we had OAT of 30 and we found it to have loads more power at all levels.

Starting the engine in -15 was easy back in the Winter and the same in the Summer with 30 degree's.

It out performs the standard Raven in every respect so far.

Hope that helps, feel free to P.M me if you need more information

Happy

[alpinehelicopter]

Dear Happy landing!,

thank you for your reply.

At what weight have you flown at 8000ft and have you landed (IGE/OGE-performance)?:D

[Happy Landing !]

AUW as far as I can remember....

Certainly with full fuel and two up, we cruise at 100kts pulling 22 1/2" MAP.

Full fuel and One up we achive 115kts on 23" easy!

ROC with Two up can go off the scale for a moment before it settles.

[headsethair]

Happy Landing! :
"Not as high as 12k yet, but 6 - 8k in OAT of 25, the Raven II performs very well. This August we had OAT of 30 and we found it to have loads more power at all levels. "

An OAT of 30 at 8k ? Where were you ?

[Happy Landing !]

Doh! Phrased that wrong:confused:

I meant that we had from -15 to +30 at ground level.

[kates]

Life seems to be good to me, I have the opportunity train for the R44 type rating - and somebody else will pay even though I am a simple simple PPL H pilot.

So I'm trying to find out what is required within the JAR-system.

Is there any minimum no. of hours req. for (the) type?

What kind of examination am in to? PC/Skill test?

What kind of examiner is required to execute the skill? PC-ONLY?

Many of you surely wonder how I could receive such training for free. However I am mngmt consultant working primarily with aviation issues and clients within the industry.

Very thankful for any suggestions on the subject.

[rotorcraig]

My understanding is that an R22 pilot can convert to R44 in around 5 hours (assuming all goes well) and that a CFI needs to assess and sign off each new type.

Could be wrong... keep threatening to convert but haven't yet!

RC

[Camp Freddie]

Hey Kates

for all questions like this you will find the answer, (well as far as the UK interprets JAR) at
http://www.caa.co.uk/docs/33/LASORS.PDF

for this question have a look at section F8

>Is there any minimum no. of hours req. for (the) type?

5 including LST (licence skills test) as RC says

>What kind of examination am in to? PC/Skill test?

LST is basically general handling to include all exercises required for initial PPL, but not navigation.

>What kind of examiner is required to execute the skill? PC-ONLY?

minimum of FE(H) who is authorised to do LST (initial issue) and LPC (renewals)

regards

CF

[Isallobaric]

A question for helicopter designers and operators....

What sort of maintenance cost savings might be achieved with a HUM system on a light helicopter, if any ?

Clearly (I think) there would be a safety benefit. But how about possible increases in component lifetimes, lifed components changing to on-condition and maybe even reduced insurance premiums ?

Just idle speculation, prompted by the recent R22 rotor blade life restrictions, and the observation that the electronics needed to perform HUM is quite straightforward. Certification is a different matter.....

[Flytest]

Isallobaric

that the electronics needed to perform HUM is quite straightforward. Certification is a different matter.....

You hit the nail right on the head. Monitoring systems are good, they improve safety, and if used properly they can give significant cost benefits (I won't bore you with how). BUT, certification is a key issue, and also all of the systems generate a certain amount of instrumentation errors, false alerts etc, in short, not good enough to support on condition maintenance just yet.

However people like my employers, Sikorsky, Smiths etc are striving to improve the systems. Maybe someday. :ok:

[Isallobaric]

if used properly they can give significant cost benefits (I won't bore you with how)

Well, I was hoping someone might, actually :D

Here's my idea:

A low-cost HUM system for an R22/R44 is technologically quite straightforward - just a DSP and a few accelerometers, with some time-frequency analysis software. Such systems are widely available for monitoring machinery.

Price ? Well I can buy an EGT/CHT monitoring system for a six-cylinder fixed wing engine for about $5000, fully approved. I reckon this is about the same level of complexity as a simple HUM unit.

So let's say it's possible to sell an R22/R44 monitor for $10,000. Is it conceivable that maintenance savings over the life of the helicopter could pay for this ?

(To placate those who actually know about these systems - I realise that the above is highly speculative, I'm just trying to find out how many orders of magnitude I'm out by.)

[Flytest]

As with anything else, HUMS is a question of money.

Data collection, i.e. "Just a few accelerometers" and "some time frequency analysis software" Sure, cheap as chips. The key though is not just data acquisition, but processing, its what you do with it that makes all the difference.

For example, vibration as we know does not do your aircraft any good, so to minimise, first up, we make sure our rotor generated vibrations are at the absolute minimum, so you need RTB.

Next Transmission, do these aircraft suffer much in the way of defects? If yes, then you need a good monitoring technique, if not, then is it worth the investment?

Engines? The engine has been around for a long time, not the smoothest, but a pretty stable platform, so worth the cost of an engine monitoring unit? The fan can and does generate a lot of vibration, so a bit of fan balancing would be nice.

Now driveshafts? this is a good one on the robbies, do you want to monitor shaft vibration? I would suspect so, at various locations, not least around the drive belt assembly.

This is getting deeper and more expensive by the minute.. a good method of saving money is better maintenance planning, and spares provisoning. Reducing vibration will save you in the long term on spares provisioning through reduced wear rates, but better maintenance planning will reduce your downtime. So early warnings of a potential fault can allow this, so I guess we need all that engine and transmission data after all.

Component vibration level trending and fleet averaging is the simplest method of establishing a baseline, from which you can determine if something is going amiss, alternatively, the manufacturer can advise on vibration thresholds. Also are you going to sift through the data on a flight by flight basis or will you require software to spot threshold exceedances? You will also need a means of data archiving and storage.

It can be an expensive business, as no doubt Nick, Shawn and others will tell you. You need to be clear about what you want to achieve within your budget, and then decide if its actually financially viable. On a Robbie, I'm not so sure, but then from a safety point of view, I do believe that all helicopters should benefit from HUMS and what it can do, sadly I don't fix the prices, or I'd give it away.

Good luck. :ok:

[The Nr Fairy]

Has anyone got an R44 Raven (hyds, no fuel injection) with a battery in the ENGINE compartment, rather than under the console ?

Why do I ask ? If it's in the engine compartment there's better CG flexibility, especially with a porker like me in the flying seat.

The POH says the battery can be in either place, but with no indication of how to tell which S/Ns divide the two configurations.

And if anyone has had theirs moved from the nose to the engine compartment, care to tell how ?

[helimatt]

G'Day NR,
Dunno if this is of any use to you, but according to the R44 parts catalogue, serial numbers up to 0945 have the battery in the engine bay while 0945 and subsequent have it in the nose.
I had a quick look in the maintenance manual and couldnt find any further info, but it was only a quck look due to time constraints. I wouldn't expect any great dramas shifing the battery to the engine bay, however you would need to have a new load data sheet issued.
Hope this helps.:ok:

[belly tank]

There were "heat issues" with the battery in the back

Mr S!!

There sure are! have you had the problem of restarting soon after shutting down in an astro, my experience is that the battery is very lazy however wait 45 mins or so and its fine, im not an electrics wiz and im not sure of the cause. we replace our battery in our 44 every autumn (fall for you yanks out there!!) we use a concord xtra crank and it works just fine, however i like to have a fresh battery coming into winter as they can be real pigs to start when its cold, not sure about the injected version though.

cheers

Mr S

ive had numerous occasions where we try and start our astro after not long shutting down and its a real struggle she labours and moans, but wait 45 mins and its fine. i like to replace our batterys coming into winter with the concord xtra crank and it works fine, they can be a real pig to start in the cold but not sure how the injected versions go?

there is a real cg problem already with the astro's bit of fuel and fat asses in the cab and she has her nose down further than an echidna!!

cheers

Mr S

ive had numerous occasions where we try and start our astro after not long shutting down and its a real struggle she labours and moans, but wait 45 mins and its fine. i like to replace our batterys coming into winter with the concord xtra crank and it works fine, they can be a real pig to start in the cold but not sure how the injected versions go?

there is a real cg problem already with the astro's bit of fuel and fat asses in the cab and she has her nose down further than an echidna!!

cheers

[The Nr Fairy]

So essentially the battery move was made because it was getting a bit warm, which isn't a problem on the R22 since the battery (if it's in the engine compartment) is in the free flow of air, and the engine is smaller.

So how about losing a bit more weight and putting a few ducts in the fairings ? Or am I being simplistic ?

[needwork]

Just curious as to wether or not an r44 astro can be equipped with permanent or pop out floatoation devices we believe it can be but has anyone done or seen it done to one

[SilsoeSid]

Doesn't an R44 with floats become a Robinson R44 Clipper?

"The R44's exceptional design and proven performance make it ideal for a variety of private, business an utility applications. To allow extended flight over water, the R44 is available with either fixed or emergency pop out floats (R44 clipper). "

http://www.helizona.com/images02/hd_clipperok.jpg
Both fixed and pop out.
http://www.helizona.com/images02/pkbat2.jpg

[headsethair]

You can't retro fit floats to the R44. But you can order the Clipper I or II with either utility floats or pop-outs. http://www.robinsonheli.com/Clipper.htm

And they don't make the Astro anymore.

[dzeroplus]

You can in Australia!

Get the details from Dennis at www.brazakka.com.au

[needwork]

we would love to to get a new clipper 1 or 2 but hey not everyone has A$650k hanging around thanks for the feedback we had heard that it had been done in Aus before.

[HeliEng]

Needwork,

If my memory serves me right, I seem to recall a customer wanting the benefits of floats, but the option of plain skids.
The aircraft came with two sets, floated and plain, from the factory. The only thing was that it was a Clipper airframe.


I could be getting confused (which is, at the end of the day, entirely possible!!:\ :\ ) but the more I think about the more it sounds right!!

Hope that is of some help.

[Flingwing207]

We have a Clipper II with both fixed float and regular skid gear. The Clipper has extra anticorrosion protection, an additional bit of stabilizer on the empennage, position lights on the rotor mast fairing, and an second (white) anticollision strobe.

While the Robinson advertising calls the fixed floats "fixed utility floats", the POH tells a different story. Water landings are not recommended except in emergencies. Depending on the weight of the helicopter, when the Clipper is floating the water level may be near (perhaps at) the door sills.

It is a great helicopter, and having floats sure eases your mind when flying over all the lakes we have up here! Changing the skid gear takes well under an hour as long as you have the hoist fitting and a big enough hoist or crane.

[cyclic_fondler]

Has anybody had any experience of having to "pop" the floats when doing an autorotation into water. Just wandering how the helicopter behaves in the air when the two inflatable shoes are filling up.

Just curious.

[andrewm]

Hi all,

I'm having a lot of trouble starting my R44 with the cold mornings. Stupid sunrise flights.
There is no primer kit installed.
Does anyone have some good techniques, or tips so that I don't flood the engine or destroy the battery/alternator.

Andy M

[helimatt]

These things can be a real swine to start when its cold. Never gets cold enough where I am to have a problem, however a few friends down in Perth that drive them reckon that if you raise the collective and pump the throttle several times and then pump it some more, it should start ok. Obviously make sure the lever is down and the throtle is shut before you hit the key;)

[sling]

Agree with Helimatt, the infrequent cold starts I've had to do in the 44 where performed as described above..

Good luck and make sure the throttle is closed before hitting the ignition, can be costly otherwise (from experience).

[dammyneckhurts]

I assume your leaving it outside overnight? They need warm air in the airbox to help vaporize the fuel. If you are able to come up with an electric heater that blows warm air, aim it under the airbox for 10 min before you try and start it. Don’t put it directly under the box incase it drips fuel. If there is any wind you need some sort of wind break. Note of caution, don’t twist the throttle or move the collective up while the heater is under there. (Dont need any fuel dripping) Of course make sure the heater isn't blowing hot enough to melt anything, or blister any paint.

Make sure you have everything organized for the flight and last thing you do is remove the heater. A few twists of the throttle with the collective up to prime it, and start normally.

Many moons ago I was unfortunate enough to be stuck overnight in the bush due to snow and zero ceiling. We woke up to 3 inches of snow and temps well below freezing. I tried the Robbie a few times and it didn’t show any intention at all of starting. We were about 150 miles from the nearest road. We lit a fire (away from the heli) and stuck a shovel filled with sand in the hot coals to warm up the sand. We then pressed the warm sand against the bottom of the airbox with the shovel. It started immediately.

The heater trick is kind of a last resort if you cant roll it inside overnight. Darn primers never seemed to make much diference anyway from what I can remember....

DMNH

[Bluegold]

From your post I guessed you fly a Raven I. The Raven II has similar problems starting ie. engine flooding and little reaction from the starter motor, the difference being it happens when the machine is hot.

Recommended to prime the engine with mixture full and Magnetos off, full throttle for around three seconds before trying starter for another 3 seconds.

Then close throttle and follow the Robinson manual start-up procedure. Haven't tried it yet....will report on success rate:ok:

[RobboRider]

Having just done a trip round half of Oz with 4 R 22/44s can relate our experiences.

We had quite a few cold mornings with difficulty to start.

We had a can of "Aerostart". Actually we a can of its generic equivalent "Start-ya-bastard". It is an aerosol can of some sort of highly flammable stuff. As you can see I really know what I am talking about too :O
I had never seen it before but the guys I was with have used it on previous trips. So I watched them use it first and got them to do the spraying while I turned over the engine. Started quick every time except one - Tamworth -with ice on the bubble covers. The battery ran flat so we had to jump start it from a four wheel drive.

Now I am told there is a risk of doing bad things to your engine so I take no responsibility if you try it and and if it happens. I think the problem can arise from spraying too much but exactly what it can do I don't know.:sad:


What you do is:

Get a rag folded into a wad. Need one person on the controls and one on the spray can. Place the wad over a bit more than half or so of the air intake opening. Hold the can ready and when the ignition is turned on spray short bursts of spray into the air intake. Most times it fired up on first or second turn.

I would recommend asking around and finding someone who has used it and really knows what they are doing. I was just a grateful bystander - so-to-speak. But at least you know the stuff exists.

[helimatt]

I would strongly recomend AGAINST using Aerostart in a heli engine. It is a product that contains a large amount of ether (which is good for putting the nighbours dog to sleep when it wont stop barking) and it is gererally used to get tired diesel engines started. For some reason the prolonged use of the product seems to cause the engines to develop a dependence for it and often wont start without it, the last thing you want in a $35000 donk.
This advice has not come about from personal experience, but from what I have been told by other people. So it could be totaly incorrect
Regards

[ground effect]

Helimatt wrote

`prolonged use of this product (aerostart) seems to cause the engines to develop a dependence for it....`


:confused: :confused:

I have no personal experiences to offer concerning this situation but a machine with a dependence problem???:confused:

If this problem does occur, is on going and gets worse as the aerostart process is repeated is there anyone out there who can explain the science behind what is happening :\

Not doubting you or your information source Helimatt - would just like some type of mechanical clarification/explanation to aid in the possible expansion of my knowledge base.

:)

[Happy Landing !]

Simply open and close the throttle 3 or 5 times BEFORE hitting the start key (Raven 1).

Raven II - Throttle closed and prime for 5 seconds.

Worked for me in -20 with the machine kept outside (Covered up though)

[andrewm]

Thanks for the replies.
I am using an Astro, and I dream of one day having a hanger to use. I like the idea of the heater, but this isn't practical for me.
I have been raising the collective several times with the mixture set to full. With the collective raised, I'll pump the throttle. Some people say pump the throttle up to 15 times. Surely that is too much?
This morning it took over ten minutes, before I had to resort to the jump start (external battery ) technique due to flat R44 battery. When it did start, the Alt light remained illuminated for 40 secs, before turning off. The Alt load meter was very positive before returning to the normalised state. I viewed that this was due to the alternator output being drained by the weak R44 batt.

Andy M

[dzeroplus]

Nothing wrong with 15+ primes with a cold engine sat outside all night.

Our Astro can take 30 primes before the fuel starts to leave the carby (that is when it is too much).

Our Raven 1 only needs 8 primes when cold and been outside all night, but they all start within 2 seconds of turning the key and no need for external power.

I have also heard of the lift the collective up and prime with the lever still up technique, don't know what difference lifting the collective is going to make!

[Spunk]

We once got stucked in the middle of nowhere, temperatures went down to - 30°C and where still down at - 20°C in the morning when we were trying to fire it up.
We were using the same kind of stuff RobboRider was talking about (I think it was called "Auto Start Pilot" :O ). This in combination with the priming worked just fine.

But then the mechanic came up with the idea trying to find out what the limitations for the R44 were as far as cold weather operations is concerned.
At those times the factory told us that if we were able to fire it up we were able to fly it. "Just give it plenty of time to warm up."
Any news on that? Haven't been in a Robbie for quite a while.

[RDRickster]

I've used the same techniques as RobboRider and Spunk have... give it a short blast of "whatever-you-call-it" in the air intake as someone is cranking the machine. It works very well, and I haven't noticed any increasing need to use it over time. I've only done it on really cold mornings (not too many of those in Maryland except January/February).

[moosp]

At a Robinson safety course a couple of years ago at Torrance Pat Cox was most emphatic that to prime the engine before start, when the primer is not fitted, you should raise the collective, then twist the throttle.

Most people that I have watched twist the throttle when the collective is down. I am not sure why this is ineffective but I believe it must be to do with the way the vapour distributes into the manifold when the raised collective allows the vapour to go past the butterfly.

I have also seen people on cold mornings give five quick twists of the throttle then hit the start key. No start. What you should be doing is to wait for the squirt of fuel to vapourise into the manifold, which may take ten to fifteen seconds on a cold (i.e. ISA -15) day.

One day all aircraft will have fuel injection. Aye and maybe one day man will fly to the moon...

(Irony alert ;) )

[pilotwolf]

Slightly off thread but I m sure there is also something in the handbook - at least in the R22 one - about not jump starting the aircraft.

I believe there is a risk of damage to the alternator and charging system due to the excessive load?

Haven't got POH with me so can't check.

PW

[rotorboy]

Rasie the collective, then twist throttle to prime (3-5) times works well.

Just think about why this works... when your flying, rasing the collective does what? > adds power, right, so more fuel is being allowed to flow.. same princible on the gorund, with collective down, like it would be at ground idle, not as much fule flows as in flight with the collectove up...

thats why haveing the collective up when priming , it works better:ok:

Collective up - trees small, collective down trees big.

RB

[headsethair]

So - why is it that when someone starts the engine with collective down and throttle open, they blow the metal to bits ? Lots of black (rich) smoke and grinding noises.....and a $30,000 bill.

[bellfest]

Andrewm, I would be getting your engineers to run through the mags and the starter vibrator to make sure it is all set up right. It could be as simple as running a bit of emery paper through the points on the starter vibrator cause they can be a bit finicky. They should start hot or cold with no trouble if they are set up right.

[rotorboy]

headsethair.....

we are talking about priming , not starting, right.... No one ever said anything about starting with the throttle open... common sense I would hope.... Though cracking the throttle just a little on a piston to help it start , has been known to work...

rb

[EMS K-MAX]

AndrewM you said that you were worried about damaging your battery and alternator. What about your stater motor. if its taking you over 10min to start i would say it wont be long till your starter motor is rooted.
Also if you worried about your battery try connecting the jumper leads before she goes flat.
As far as jump starting a 44 goes you are ment to pull a few circuit breakers first. check the manual that will tell you which ones.
Hopfully its not your machine that is reciving this early morning punishment.

[the coyote]

Surely twisting the throttle to full open does just that, regardless of what the collective correlation cam is doing, full throttle is full throttle wherever the collective is.

I used to give it about 10-15 pumps of the throttle and then immediately hit the key. Then as you crank it very slowly creep the throttle open but be quick to close it again as soon as it fires.

[Steve76]

GET ETHER.

Get engine running and then stabilise it before engaging clutch. Yeah yeah.... I know that the clutch should come on straight away. But just bleed it in like a H300 and don't let the engine stall.
Don't like that? Then sit there until summer.

[dzeroplus]

I am with the Coyote, full throttle is full throttle.

What difference does lifting the collective do?

The accelerator pump works by throttle regardless of the collective position.

[Head Bolt]

Coyote and Dzeroplus are right. The collective cam simply acts on the throttle butterfly, and as such the position of the lever is immaterial if priming using full throttle i.e full throttle can be used manually at all times regardless of where the lever is.

More worrying than cold starting is the lack of understanding of this basic principle which is becoming evident from some of the replies being posted.

Fly safely all

[vorticey]

HEAD BOLT
pretty sure to get full throttle the collective needs to be up.
but we arnt looking for full throttle, you just need to pump some fuel into the manifold (3-5 pumps) and wait a little while for it to evaporate (as moosp said). but if its too cold for it to evaporate thats when you will have trouble.

[46Driver]

Trying to get some information on how they stack up. I've got a few thousand hours in the TH-57 JetRanger but hopefully some of y'all with experience in both can tell me how they stack up. I know the Bell has a max gross of 3200 lbs and the R-44 tops out at 2400 lbs - any more comments on payload, range, speed?
Thanks.

[Vfrpilotpb]

For me it would only be the 206, it feels much easier, and with its turbine thingy rather than the old recip donkey, it sounds right as well,, but then thats me and my thoughts!
Peter R-B

[delta3]

I use the following on my Raven I (without primer)

- twist trottle as many times as you wish (5 - 10 times)
- using full collective (pumping then twisting) gives still extra fuel, since it gives extra pumping effect to the carburetor
- when it is cold (below 5° C), it is very hard to flood the carburetor, but don't try this at higher temperatures

- if the heli is protected from the wind I just have a 200 W infrared lamp on the airfilter below for 10-15 minutes, getting it to warm up a few degrees (probably putting the pan to 5-10 °C). This requires access to some form of electric supply. As said by others I avoid risk of contact with fuel or oil by placing the lamp at the side.

- Robinson confirmed me that in cold weather, first start, it is quite OK to wait a few more seconds until engine runs ok, before clutching. The strain on the system when stalling (or trying to avoiding it by reving) is much greater

[Ascend Charlie]

Horses for courses.

For charter work, carrying two couples is the norm. In a 44, one of them stays behind, or, more likely, you don't get the job.

No boot is the biggest reason not to buy a 44.

[Warren Buffett]

charlie s charlie - you sure the 206BIII can cruise at 115kts? Mostly they tend to do between 100 to 110, right?

thanks.

[charlie s charlie]

Figure came straight off the Bell Textron Website, hence my large caveat at the bottom of that post!

[imabell]

r44,
3 pax, no bags, not under the seats if you are sensible.

bell 206,
4 pax, 4 sets of golf clubs in the boot. very sensible.

warren buffet. 100/110 kts max with a load generally although some seem to get along a bit quicker.

the r44 has all the good flight characterisics, especially with the hydraulics. the best machine in auto and the 540 sounds great.

no payload stuffs it.:(

[46Driver]

I saw the R-44 II has an extra 100 pounds of payload - is that correct? (max gross of 2500 lbs vs 2400 lbs)

[EMS K-MAX]

no thats not correct

[charlie s charlie]

The Raven II has a 100 lb increase in gross weight, but also a 64 lb increase in empty weight. So you get another 36lb of payload in the Raven II.

[DualDriver]

Being current on both types, (still prefer the 206) I can cruise the 44 Raven II at a comfortable 115kt. Where I am operating, I have had full fuel and pax in the 44 with some power to spare. The extra HP on the Raven II comes in REALLY handy.:ok:

[bellfest]

Collective position will most definetly have an effect on throttle travel. 100% at flat pitch obviously uses less manifold pressure than in the flight position so the engine fuel/air demand is less. The butterfly opens further when the collective is raised to allow more intake(That's what correlation is). When the collective is full up the butterfly is full open unlike at flat pitch.Watch the throttle arm, wind it to full throttle at flat pitch and lift the collective and see what happens. At full collective the accelerator pump also has more travel so you WILL get more fuel for priming and because the accelerator pump is spring loaded it's a good idea to pause momentarily at full throttle to let it do it's thing.
The lack of understanding of something as simple as correlation is a bit scarey. Pilots should be made to learn this **** and retain it

[The Nr Fairy]

First - our maintenance organisation tells us that an initial 25 hour oil change, then a 50, then 50 hour intervals is fine.

We've had the oil change and 50 done somewhere else - more convenient - and and they've suggested oil changes every 25 hours. Any comments / experiences from the rest of you ?

Also, the aircraft is - despite gentle washing with water, chamois and sponge, starting to need a decent clean. What do you guys use - is there one good commercial product, or does Windowlene and Mr Muscle figure highly in your cleaning kit ?

[helimatt]

G'Day NRF,
IIRC if you run a full flow spin on oil filter, you can stretch your oil changes out to 50 hours. However, oil is fairly cheap and it would be definitely in the engines best interest to change it every 25 hours irrespective of how many filters you run.
We use truckwash on our 44. It doesn't do a bad job, it even gets most of the lead deposits off the aft cowl
Cheers

[Dantruck]

A wise old engineer I once knew said: "Oil is cheap, metal is expensive."

Lycoming says 25hrs. They designed the thing. Why not trust what they say?

I recently checked over a R44 Astro that obviously had been run to 50hrs, albeit with top-ups. The oil had a distinct burnt smell to it. We didn't buy it!

Dan

[belly tank]

NRF

I would stick with the 25hrlys myself unless youve got a filter kit like HeliMatt has suggested.

The lycoming engine operation manual says for a 540 that at 75% power it should burn about 0.7 of a quart of oil per hour and this works out about true.

for the wash we use Truck wash also its good stuff and will do the job your looking for. windows we use a perspex cleaner or windex does the job fine!

all the best with your new machine!!

[bellfest]

NRF
Go with what the lads are saying mate, your engine will love the 25 hr oil change, that will keep it gold and the wear and tear on your engine will be much less. Teepol Gold was always the best for cleaning but I think it has been bought by another company and they have changed the name of it and it's a bit how's your father now but if you can find any agents with the old stuff I would definetely grab it, failing that CT18 (truckwash as suggested) is the next best thing. Perspex cleaner made by Permatex comes in a square metal tin and it's worth its weight in gold. A company called Cyndan also makes a good perspex cleaner,you will find them easy enough on the net.
Good luck with the new rocket

[Spunk]

This is what Lycoming suggests:
Cold wx starting (http://www.lycoming.textron.com/support/publications/maintenancePublications/serviceInstructions/SI1505.pdf)

[airborne_artist]

Eclipse from www.chemiclean.co.uk/traffic.htm (http://www.chemiclean.co.uk/traffic.htm) works well with a pressure washer.

[RDRickster]

That guidance was obviously written for the stuck-wing. You can't access some of the areas for preheat (most notably the top of the engine). Also, the "alternate power supply" isn't exactly recommended by RHC. I don't suppose they have any rotor-craft specific recommendations?

[headsethair]

"works well with a pressure washer."

NEVER NEVER use a pressure washer on a 44 - factory warning. See POH for all cleaning tips - and be really careful what you use on the perspex. Windex & a rag + dried on bugs and crud = a lifetime of scratches.

[sling]

Go with all that's been suggested above..... big plus on the 25hr change.

Only tip I can offer is to us car wax on the back panel... It makes life alot easier getting the exhaust soot off.

Have fun with your 44

[Spunk]

Sorry about that RD,

I was on the run when I found that service instruction and didn't even have enough time to read.
For some reason I always assume that everybody in the aviation world is flying helicopters :}
Why would you want to fly anything else???

[slowtyper]

I would strongly suggest you follow the advice bellfest gives, especially if the other priming techniques are not working. I had this problem once and it ended up being the points out of sync a tad. It only seemed to be a problem on the first start othe day.

[CyclicWaggle]

I would strongly advise AGAINST using any ether products to start an aircraft engine. The reason they seem to become dependant on it for starting when it's used too much is that it's so bloody explosive that it buggers the piston rings and so the engine looses a lot of it's compression. Have had to use it in the past to start a ratty old company van on frosty mornings - it used to make the engine knock like a ba$tard for a good 10 minutes after starting. When there's only 1 engine keeping you aloft, the last thing you want to do is pi$$ it off!! :uhoh:

[goaround7]

Not sure about best priming route but on Astro, I & II, a technique borrowed from Enstrom pistons works a treat here in SA when we start at up to -5. After you've finished priming, lean the mixture and hold the throttle full open for 8 seconds. Then CLOSE IT AGAIN and start. Usually works here.

[slowtyper]

I would suggest you have a look at what Bellfest recommended, it had nothing to do with aerostart. He suggested getting the mags and the starter vibrator checked. Good advice if you ask me!!

[bellfest]

Has anyone had/know of any ring gear problems with R44's. A couple I have seen with not even a 100hrs tt have spat a few teeth off the ring gear. They both start well as far as I am aware and the lads flying haven't reported any starting mishaps. I haven't looked at the machines as yet but I'm guessing that the starters are not properly shimmed or it is an inherent problem with the 44, particularly being new with the belts gripping so much and loading it all up a bit more cause no one uses talcum powder to reduce the friction of new belts. What do you all think of the talcum powder thing?, anyone else do it/done it? I think it is as close to vital as #*%$ is to swearing

[belly tank]

No Problem with ring gear on our Astro.

however we have used talc on the belts in the past. I know when belts are new they are very tight, trick is to have a good strong battery.

we had a new set of belts replaced at about the 1000hr mark, they were a real tough set and took a long time to stretch, now about 300 hrs later they are just fine with a good,smooth engagement.

i still think that a strong battery will do the trick, we replace our batterys every year coming into winter.

[dzeroplus]

About 18 months ago from our 3 R44's we had ring gear problems with 2 of them and after replacing the ring gear found similar teeth stripping and slipping as you have mentioned.

Probably only got 300 hours from the new set of ring gear from both choppers, our engineers put it down to mismachined ring gear.

Robinson did not agree and consequently did not receive a credit.

After fitting the replacement set we kept a careful eye on the starter motor nuts (especially the one tucked in behind the starter motor and a nightmare to tighten).

We found the nuts were gradually loosening and we appropriated this to the ring gear slipping problems and since locktighting the nuts and have had no problems.

We have found it most beneficial to change the starter motor inconjunction with the ring gear.

Hope this helps (Our choppers were an Astro and a Clipper if this makes any difference)


:{

[Gaseous]

Things to make it go bang!

Experience (bitter and expensive) from Enstrom (non turbo, high compresssion) which are notorius for shedding ring gear teeth. I assume the R44 uses retard breakers and not impulse coupling.

1) anything to make it fire before the piston reaches top dead centre while the starter is engaged. Check mags to make points are ok, p leads are sound, capacitors are properly grounded, distributers work.

2) check starter vibrator to make sure normal points are inactive whilst starting.

3) check timing of retard points (Enstrom 1/2 degree after TDC)

4)Battery must be good so it has enough momentum to take it over TDC. If the piston is on the way up on compression when you disengage the starter, As soon as the switch goes from start to run the main points are activated. If this happens at the right point of the piston stroke, the cylinder may fire before the starter has dropped out of mesh. If this happens and causes a kick back - no more starter ring/starter motor.

5) Starter motor must not be lazy, for the same reason. I had one with an internal fault which made it slow. It killed the ring gear and smashed the motor casing.


If a cylinder fires before TDC whilst starting, it not only removes teeth from your ring gear but can also smash your starter motor to bits.

[raven2]

Does any body know if it is possible / safe to fly in a R44 with a passanger and two sets of golf clubs across the rear seats? I was thinking that if the clubs were properly secured that it should not be a problem. Has anybody ever tried it?

Regards

Raven 2:confused:

[headsethair]

Why not lift the rear seats and stand the clubs upright in the baggage area ? Then clip the belt through the handle of the golf bag.
Or take up tennis.

[Steve76]

Make/buy a cargo net that goes from the beam across the rear of the front seats and is anchored/clipped to the seat belt upper mounts on either side.

Do you have Helipods? Do a google search. Made in NZ. Just the cats pyjama's for the R44. Makes it into a useful helicopter.

Barring that, just toss the clubs in using the seatbelts. Its only going to be an issue if you crash, or you go negative and your balls come out.......:E

[Helinut]

Steve,

Unless the situation has changed our wonderful CAA does not permit us to fit such things on UK R22/R44s. It would make the aircraft too useful and we might be able to use them sensibly :rolleyes:

[Gaseous]

You could always strap them to the roof rack. One on each blade should keep things sweet.

:} :} :}

[eagerbeaver]

or you could just buy a new set of clubs at each different course - R44 after much investigation realised its a pretty useless machine for things like this - you cant physically fit your gear in the cabin.

[RDRickster]

http://img78.photobucket.com/albums/v238/RDRickster/Flat_Platform.jpg

I can't remember the bloke that built this setup, but if you do a search on the Robinson forum you may find him. He has several pictures available. Check here for links and other info...

http://www.r44helicopters.com/

[pilotwolf]

As an aside...

Not sure what metal they contain but be careful of the effect they have on your compass.

PW

[Helifan]

Hi

Apart from the obvious differences between the Raven Beta and Beta II (ie. fuel injection, speed, cost, etc.), what are the pro's and con's (if any) when comparing the two machines?

I am planning to purchase a Raven II but have been told that because it is a relatively new machine, it still needs to prove itself in the market, whatever that is supposed to mean.

Thanks.

[RDRickster]

If you fly at higher altitudes, then you'll appreciate the increased power and additional payload with the Raven II. If you fly mostly at sea level, don't waste your money... get the Raven I. Don't neglect the carb heat and you'll enjoy that ship.

[headsethair]

The Raven II is a major improvement over Raven I. I have flown Raven I for 3 years and just got a Raven II this spring. Totally different machine. Quieter (the blade end caps), more power which makes a big difference if you fly close to MTOW and the changes to the main blade have definitely improved performance. 18" hovers at 2000 ft are possible in no wind with full tanks and 3 up.

The increased payload is a bit misleading - the 100 lbs is actually only 75 because of the weight of the fuel injection gear......

Values of R44 Astros have plummeted in the UK as a result of Raven II success - and the same will happen to Raven I as soon as the new factory comes onstream at RHC and they reduce the wait time.

If you value your investment, do not get a Raven I.

But if you just want something to bimble around in for 10 years and you want to wait a bit.......go for a used Raven I once the prices start to drop.

Do NOT get an Astro.

[ppheli]

>> it still needs to prove itself in the market

hmm.. and they have produced 450 so far (#448 ws reg'd in UK last week). Sounds pretty much like it's proved itself..

[RobboRider]

The Raven II fuel injected uses a lot more fuel. An operator here is regretting (to a degree) getting one. Has a bit more max usable load but not much.

depends what you want to do and where.

[headsethair]

Strange, 'cos we're seeing 1 litre per min which is what the 44 normally consumes in all guises. At sea level - or beneath sea level as life was in London yesterday. :sad:

[RobboRider]

Can't remember exact figures quoted to me but it was in the ball park of 56l per hour for the Raven 1 and about 70 for the Raven 11.

That's here in Oz with higher temps - 25 - 35 celcius most of the the time. But was also mostly at sea level sorts of altitudes.

[Gaseous]

Robborider,

If fuel consumption is that poor, perhaps it would be wise to get the injector checked out. It may be just that one aircraft.

If it is the same injector as an Enstrom (Bendix RSA) then correct adjustment can make a huge difference to fuel consumption but no apparent difference to performance - until the plugs foul up.

I have flown Enstroms with big differences in the full rich consumption.

Incorrect injector adustment is less of a problem on an Enstrom as hitting the lean knob in flight is routine. I don't know if anyone dares to do it in a Robbie.

[SFHeliguy]

Hummmmm....

I bought a Raven I 9/03 and have about 200 hours on it. I have also flown another Raven II for at least 15 hours. My flying goes from the mountains near Yosemite and up north in the trinity alps to basic tours around the California coastline at sea level. Here's my general feelings:

1. Robinson makes really good, simple, cheap helicopters. Just can't find anything that touches them for what they put out. Granted, I'm sitting on a well maintained and hangered / less than 300 hour machine.... but so far I love it.

2. There is a performance difference at altitude between the 2. I notice with 2,200 lbs or so, once you get above around 6,000 ft on a reasonalbly hot day in the summer, you're going to need to slow down a bunch in my ship (Raven I). I have had mine up to 11,000 ft with one other guy and a bunch of gear but it was a constant source for concern and a good lesson in watching MRRPM.

On the other hand, going over the same mountains on the same job, over the same course in the Raven II you really can notice the difference in altitude performance.

3. Fuel Consumption - I was surprised to find that in an apples to apples comparison (again, doing pretty much the same job in 2 different ships within the same month (April 04) in similiar conditions), I was surprised to find that the Raven II got about the same fuel consumption.

4. Payload - Don't count on the extra 100 lbs making much of a difference.

=====================
Now, that said.. here's some unsolicited stuff...

1. Get the bubble windows - Much better than the stock stuff and worth it.

2. Get the instant VSI - It's pretty nice if you really need to know exactly what's going on.

3. Don't get the Robinson cart - I like the heli-tow cart from the guys in Canada. It's smaller and cheaper.

4. Get the 9 hole pannel and an AI - Nice to have and if you ever decide to do instrument training in it, you'll have a nicer setup than the instrument trainer pannel (kinda big and view blocking).

[RDRickster]

There have been a few previous posts on this general subject, but I wasn't able to find any SPECIFIC numbers relating to the R44 operating costs from the field. Therefore, what is your average HOURLY operating cost (include unscheduled maintenance, regular inspections, scheduled maintenance, fuel, and oil ONLY)?

Please do NOT include the purchase price, financing of your aircraft, insurance costs, nor any hanger fees. The answer will vary with flying conditions, type of operation, fuel costs, etc. Nevertheless, I thought it would be a useful comparison for everyone here.

Cheers!

[belly tank]

Gday! Rickster

For the criteria you are asking for your looking at around $320 per hour $AUD

cheers
BT

[RDRickster]

Thanks for the input. Here is the propoganda for reference:

http://www.robinsonheli.com/R44IIEOC04.pdf

Additional posts out there?

[George Semel]

Well, when I was in the Aircraft Owning business, I would take what ever the cost of fuel that I was buying per hour and multiply by a factor of 5 for airplanes and 10 for helicopters. So if you take franks fuel burn of 14 gal an hour @ $2.00 a gallon, its more like $3+ you get 28 dollars an hour, times 10 and you get a good ball park DOC of 280 USD an hour. its a quick way to get an Idea of what the per hour DOC's is going to be. of course you would then fine tune it a little. Frank uses the 500 hours a year to work his numbers. To not consider the other costs, such as finance, Insurance and hanger is not giving the whole story. An R-44 or any helicopter is going to be an expensive toy with out it being used to generate some sort of revenue stream. The Idea of a helicopter as a rec vehicle is at best a dubious one. You need a very large income stream to do so.

[WLM]

Hi
We have found hydraulic fluid leaking from our RH-FWD hydraulic servo assy (Part D2/2-1). Is it cheaper to service the faulty one or just plain quicker and easier to get a replacement unit?
Our reason beyound the question is the delay in getting parts or service done from the the US every time we need something, not mentioning the mark up charged by the local dealer...Sth East Asia based.
Regards;)

[evod]

Gday WLM,

In Indo i used to get parts and pieces from our friends at aviall in Singapore and Robbo parts from heliflite in bankstown. Just make sure they send the proper paperwork and mark it as anything but aircraft parts and all should be well. Same deal with the dealer in Indo.....100-150% mark up. However they sharpened their pencil when they found out you can get parts from elsewhere.

Terima kasih banyak,

evod

:ok:

[WLM]

Thanks EVOD
Do you have a contact name and number for both Asian places?
Was quoted between AUD11K and 15K by Oz dealers.
Tks
Will ;)

[evod]

WLM...Sorry for the delay.

My contact was James someone in Singas for aviall (check the website) Probaly not much help now as it was in my indo days pre Malay. Good luck with heliflite as 10 or 11 gorillas for a servo sounds sedikit mahal (ask peter for translation)

Cheers,

Evod

:ok:

[Captain Lai Hai]

sedikit mahal =little expensive

ask peter for translation is that Peter G ex S.M.A.C.

thanks fly safe

[evod]

No, different Peter.

Terima kashi banyak dan Jumpa lagi,

Evod

:ok:

[WLM]

Evod
Bahasa kamu bagus lah :ok:
Our local friend sharpened up and we're getting a part by Oct 5th;)
Cpt Lai Hai
Ur in HK?
Cheers
WLM

[SMOUC]

How do you carry two pax in an R44 with baggage that can not fit under the seat and have the baggage ' secured '. CASA does not approve the seat belt. All our 44s are on floats, so no side pods. Any one know of an EO or something like a net that is approved.

SMO

[rotaryman]

How about getting Pax to repack their bags and only take that required for the Trip!!

Or get a Bigger Machine! :ok:

[SMOUC]

B430 & B222 BIG ENOUGH FOR YA


SMOUFC

[Lu Zuckerman]

OH NO, HERE WE GO AGAIN.

You may remember me shooting my mouth off disagreeing with Frank Robinson when he said he had considered a 90-degree pitch horn on the R-22 rotorhead. (See link below.)
I responded that if the pitch horn reached beyond the cone hinge there would be problems related to controllability. It has been brought to my attention that on the R-44 the pitch horn extends beyond the cone hinge by approximately 28mm and this got me thinking. What effect does this have on delta-3 pitch coupling and blade flap?

When the blade flaps on the teeter hinge the up flapping blade would have a pitch decrease and the down flapping blade would have a pitch increase, which is what you would expect. However the blade is capable of flapping on the cone hinges and herein lies a problem.

On the R-44 if the helicopter enters into a loss of control situation and
there are extreme changes in blade position relative to the cone hinges the
pitch changes due to delta-3 will be exacerbated. You would expect that
when a blade flaps up the pitch will decrease due to delta-3 but in this
case it will increase increasing the upward flap. Conversely if the blade
flaps down the pitch decrease will also be exacerbated causing the blade to
flap downward even further. In a loss of control situation this would help speed up the process resulting in rotor incursion, mast bumping and contact with and fracture of the blade tusks.

Here is another example. Let's say the pilot at startup increases blade pitch to say 10+ degrees in order to hover. The blades cone up and in doing so increase the pitch to 12+degrees causing the helicopter to rise. What does the pilot do?

Please tell me I am wrong. Explaining why I am wrong with technical statements and not vitriol.

:E :E



Original thread is here (http://www.pprune.org/forums/showthread.php?s=&threadid=20616).
See response by Frank Robinson posted 30th November 2000.

Heliport

[NIGINOO]

Would not the coning angle remain the same? ,providing the mrrpm are correct. If this is not the case, would one assume that the coning angle on this type of head , alters depending on the gross weight of the machine.

[Lu Zuckerman]

To: NIGINOO


QUOTE]Would not the coning angle remain the same? ,providing the mrrpm are correct. If this is not the case, would one assume that the coning angle on this type of head , alters depending on the gross weight of the machine.[/QUOTE]

The coning angle is a function of gross weight. If the helicopter only has a pilot the coning angle would reflect that weight and would be a very shallow angle. If the helicopter had a full load the coning angle would be greater.

Using assumed numbers if it took ten degrees of increased pitch to get the helicopter to hover with one person aboard the delta-3 connection would increase by say 2-degrees giving a total pitch of 12-degrees causing the helicopter to rise from the hover. By the same token if it took twelve degrees to hover with a full load the delta-3 connection would increase the collective pitch to say 14-degrees causing the helicopter to rise.

What does the pilot do to maintain the hover? If he decreases collective pitch he will go below the original pitch input to hover and end up back on tera firma. At least I think so.

I believe the problem would go away after passing through translational lift.


:E :E

[4ero]

won't the coning angle increase gradually?

As you say, the helicopter will not come to a four foot hover, then all of a sudden the coning angle increases increasing aoa and lift.

The effect is present incrementally throught the motion as so is adjusted for continuosly. There's no up and down with the lever malarchy.

(last time i tried contributing to anything like this is was plainly clear i'd have trouble finding my a*se with both hands.)

[4ero]

Whats wrong with the belts. They are fire retardent aren't they?

Good enough for pax but not for bags?

[Lu Zuckerman]

To: 4ero

After giving it some thought it would seem that as the blades cone the pitch in the blades is greater than the collective input and the pilot can lift off to a hover with less collective input and if this is the case it is a good thing. However if the helicopter enters a situation where there is excessive flapping on the cone hinges (pitching over, sideslip, excessive cyclic input) when the blade flaps up the pitch will increase exacerbating the situation. The same is true when the blade flaps down pitch is further decreased and this could lead to loss of control.

:E :E

[OHALLY]

Nets are available. I have used nets that when in the stowed position are rolled up across the back of the front seats , when they're in use they unroll and clip to the top hard point of the rear seat belts. Not really a viable answer for pax and bags but they work really nice for loading the back right up with cargo

[headsethair]

OHALLY - any idea where we can get these nets ?

[moosp]

I don't know of a system that has been approved for the '44 (and I supect that Frank has never authorised one, so this will have to be an in country civil aviation authorisation) but the principle is the same as "in seat cargo" that has been used in the fixed wing world for many years.

What you need is a bag that "looks" as though it is nine g strong with loops to take the shoulder and lap straps. It should fit onto the seat looking like an overweight pax with no legs. Then get your local friendly Authority Airworthiness rep to have a look at your system.

If it looks sensible they will probably allow it on some kind of local agreement. It is highly unlikely that they will require a crash test of your machine with the bag in place, unless you operate in certain countries of which we all know...

The ones I remember years ago in airline work were heavy canvas like a mail bag, but cut in a pear shape. The volume was surprisingly large, and you had to be careful to check the mass of the stuff in it.

Try giving your CASA rep a call. Most of them are remarkably approachable on such subjects, and although they cannot legally suggest a solution, they will often give you a good idea of what might be approved if you presented it to them.

FWIW

[delta3]

Delta3, gyroscopic precession.

Lu,

I think the answers can be found in the following results
(sorry guys this is from an egg-head-pilot)

First (you never know) To the pilots : DISCLAIMER

The data is only approximative, precise enough to illustrate
the discussion points, but not to be used to plan flights.
The author declines all responsabilities.
-------------------------------------------------------------------------------------------
In the last year I have read a number of heated discussions
concerning the R-44 rotor. As I am mathematically inclined I decided
to make a detailed blade element dynamic model of the rotor
in order to investigate its behaviour. The model is pretty detailed
and even takes viscous fluid, mach, reynolds numbers etc into account.
I have 3-D animations but cannot publish this on the net.
I do want to share some curves concerning
the flapping angle of the rotor calculated for two scenarios:
1. sudden wind gust (with and without delta3)
2. sudden cyclic forward (with and without delta3)

The math shows that the rotor stays perfectly aligned thanks to delta 3
and illustrates the remarks Frank Robinson made a long time ago concerning
- right blow back because of coning (wind)
- wee-waa or zig-zag in case of cyclic transient

Image 1. Sudden 50 knts gust : R44 rotor blows back but stays aligned.
See legend to see what curves mean. The X-axis is in number of rotations.
Remark how fast rotors react to disturbances (1,5 revolutions)

http://www.e-sign.be/private/heli/R44_flap_v2c_vx.jpg

Image 2. Same without delta3 : rotor blows to the right (blade at the left is higher)

http://www.e-sign.be/private/heli/R44_flap_v2c_vx_nod3.jpg

Image 3. No wind but sudden 2degree forward cyclic: Rotor moves forward fully align both during and after the transient

http://www.e-sign.be/private/heli/R44_flap_v2c_fwcyclic.jpg

Image 4. Same without delta3 : since there is no wind the rotor is aligned after transient, but tilts to the right during the transient (blade is higher at the left during the firs 180 degrees)

http://www.e-sign.be/private/heli/R44_flap_v2c_fwcyclic_nod3.jpg

With respect to the question in this thread: the possive coning delta3 provoques no instabilities (wind,cyclic, collective inputs). It just increases coning to a design angle.

Removing this delta3 has only one effect : coning angle decreases.

SORRY ... (edited october 22)
The following paragraphs are wrong : the lift increased in the experiment because coning delta3 increased blade pitch

START OF ERROR

So I assume the following design choice were made:
1. the coning is determined by the precise lift distribution and centrifugal forces along the blade (these are fully detailed in the used model).
2. if blades have extra tip weight coning is reduced
3. a 2-3 degree coning is wished
4. the coning delta3 increases coning in this case by approx 0,5 degrees.

I could also model the R22, which I did not yet, but my guess is that the original R22 blades were lighter with less tip weight, so rotor coned enough without coning delta3.....

""(END of ERROR)

CORRECTED VERSION :

After introduction of coning delta3 the collective needs to be lowered to achieve the same trust level. So I guess this delta3 primarily acts as a simple linear (quasi non dynamic) amplifier on the collective handle. I still maintain the conclusions about the stability

END OF CORRECTION


Delta3

A very hypothetical case

Suddenly introduce the coning delta3 to a rotor.
It would in practice take a very advanced servo to achieve this,
but this mathematical scenario can help clarify a stability
question : suddenly introduce the control law in the
system and look what happens:

not oscillations, just an increase in coning angle

http://www.e-sign.be/private/heli/R44_flap_v2c_coning.jpg

Delta3

[delta3]

SMOUC

I have seen people carry just about anything on those seats: from golfclubs to dogs.

What is the formal instruction that forbids this ?. Is there a differnce between professional and private use ?

What about a dog : on a long trip it is in a cage that just fits in the rear seats and can be kept by the seat belt.
On short trips she just sleeps on a seat, and as she does not use a seatbelt this is probably not OK...

This btw sometimes also makes me hesitate when replying to the question from ATC : how many POB.... do animals count...

Delta3

[OHALLY]

HEADSET HAIR - I'm working on it ..... i'll get back to ya asap

[trackdirect]

Back in the 44 eh FIGGIE

[4ero]

delta 3: I think the P in POB is persons, not pets. (Do you have a blue hawian shirt and a KH4?) :)

How do the helipods work?
The manual states that the skids are only designed to bear weight from below and to put weight on top of them will be detrimental to the air frame.


So the issue is the baggage coming free over the top of the belt, rather than the quality of the restraints. I guess it will be difficult to maintain control with 20kg of louis vuitton in your lap.

I generally make judicous use of fat straps and infant belts to secure the baggage if it don't quite fit.

[SMOUC]

YDYJSMO ALL THE DOO DAA DAY

[RobboRider]

How do the helipods work? The manual states that the skids are only designed to bear weight from below and to put weight on top of them will be detrimental to the air frame.


I've got a set for my R22 and they have two hard points attached to the frame and the weight seems to be more suspended from them. There are a a couple of legs which fit into two brackets (one is an add on the other is the existing one in the wheel bracket.) I suspect the makers hope/believe the legs have sufficient freedom to move to allow the vibrations to dissipate around the pod.

Two sets of blades ago I could only use one pod cos when I added the second it caused a vibration so bad it used to turn off the GPS and rattle my fillings loose! (That was with a blade some goose had bent and rebent the tabs so much that even though they were out a bit the engineer wasn't game to try to bend them back anymore in case they broke. Anyway got rid of them and the new ones were fine.

So what I think I proved is that the dissipation IS affected by the pods so I only use them when I need them then take them off - even witht he new smooth blades.

[Lu Zuckerman]

Here is another point. Let's say the basic pitch setting on the R-44 measured at the root is 10-degrees (example only). The pilot pulls collective to a hover adding an additional 8-degrees (example only). In order for the helicopter to hover the blades will cone up until the lift is countered by the centrifugal force establishing the cone angle. The pitch coupling adds in an additional 3-degrees, which is added to the collective input giving a total input of 11-degrees (example only). The additional 3-degrees might or might not cause the helicopter to rise. As I stated previously this in itself is not a bad thing.

Now, let’s enter into an auto rotation. The pilot puts the collective full down but because the blades are still coned he can not return the pitch setting to 8-degrees measured at the root. The actual angle is 11-degrees and this may effect autorotation.

Possibly.

On another forum an R-44 pilot stated that you had to fight the helicopter to the ground. Assuming this is a correct statement could it be due to the pitch coupling on the rotor head during coning?

:E :E

[RDRickster]

When that pilot said he had to, "fight the helicopter to the ground" I think he meant to say he had to actively FLY it to the ground. It was the first time he'd flown an R44 and most of his time was in the smaller Schweizers. He wasn't execting to have to apply so much downward force on the collective (good thing he wasn't flying a B47).

[zeeoo]

Delta 3 ,
would you have the kindness to tell a scratching-head like me the software you used to perform those charts or from where you got them, please ?

thank you
victor

[Lu Zuckerman]

To: RD Rickster (Nee Reynolds)

When that pilot said he had to, "fight the helicopter to the ground" I think he meant to say he had to actively FLY it to the ground. It was the first time he'd flown an R44 and most of his time was in the smaller Schweizers. He wasn't execting to have to apply so much downward force on the collective (good thing he wasn't flying a B47).

I'll accept that it was his first ride in an R-44 however his having to apply more than normal down collective to get it on the ground I go back to my original premise: Do you or anyone else feel that it might be the pitch coupling due to coning that causes a pilot to have to fly the R-44 to the ground.

I also ask you to consider if this pitch coupling has any effect on autorotation since the pilot can't return the blades to basic pitch with the collective all the way down.


:confused: :E :E :confused:

[delta3]

To zeeoo

I basically put al the equations into Matlab (a powerful math solving and simulation package, now common in R&D)

The model adresses
- full dynamics: I checked this with the books of Eric Dick, Gordon Leisman and Wayne Johnson. The equations are similar, but adapted to the specifics of the R44 rotor head. It is not just a linear or first harmonic kind of thing, but the full math.
- airfoils : I assumed a 63015 of which I recalibrated the lift and drag coefficients using XFoil from MIT (freeware). This allows to refine the simple C times v square kind of stuff. Especially in the 0,6 to 0,8 Mach range
- tip losses
- reverse flow

Simplifications
- uniform inflow (I just solve - be it the full- Glauert equation to determine the induced velocity). This is not OK for 0-20 knots transition and during flow reversals such as before entering autorot, but it can be compensated (tdb)
- stiff blades . This I will refine, both bending and twisting, but for that I need to measure the blades otherwise I get GIGO (garbage in and out). I am still puzzled with the famous german film of the rotating blades, so I want to model this and simulate it.

When validating the results I had several 'sleepness nigths' not believing what I saw. After some validation work I am now convinced and 'understand' it better, although some of the stuff is at first very weard (for me at least I am not a Helo-professional).

For those who care about this egg-head stuff an example : total lift per blade plotted as a function of rotation angle, in the following case : R44 level flight (100 knots), fuel fuel, 1 POB, required cyclic and heli pitching.
I show a 'camera type picture as viewed from the front to the rear'. Looking at this I first thought : this can not be It will tip the whole machine, but actually it doesn't....

http://www.e-sign.be/private/heli/R44_blift_1POB_100K_v3a.jpg

Delta3

[helmet fire]

Rotational dynamics (def):
The dynamics resulting from a Zukerman quest for clarification or understanding, that when fully explained or answered, results in yet another example of his point without any form of acknowledging the original responses. Hence, around we go again, thus the term "rotational".

Example: Lu asks/states the R44 has a dangerously unstable rotorhead design. Delta3 kindly maths models the solution, explains it in depth, and comes up with proof that Lu's statement is unsupported. Lu reacts not by acknowledging the explaination, questioning the maths model, nor even the assumptions. Instead he replies..
Here is another point.

Rotational Dynamics at it's very best.:ok:

[zeeoo]

to Delta 3

great thanks, i ll follow your posts here..i ll try to get more about to simulate my own design ( i m not eng)
i tried Xfoil but every time i tried to make it perform the charts, i got a runtime error, so thought it was bugged...

the soft looks great, can you simulate special blade-tips ?
(BTW im looking for a complete doc about berp tips)

i really appreciate someone helping me to acquire some knowledge. Dave jackson also helped a lot
(dave you met another :sad: ..that's it ?, what has he better than me ? :p ok i suppose i ll have to live ith that :} )

thanks again delta 3

[Lu Zuckerman]

To: helmet fire

You must be spring loaded in the pissed off position relative to anything I post and I think it is clouding your vision.

Example: Lu asks/states the R44 has a dangerously unstable rotorhead design. Delta3 kindly maths models the solution, explains it in depth, and comes up with proof that Lu's statement is unsupported. Lu reacts not by acknowledging the explaination, questioning the maths model, nor even the assumptions. Instead he replies..

First of all I never stated that the R-44 has a dangerously unstable rotor system. What I stated that if the R-44 ever entered into a situation where there were extreme flapping on both the teeter and cone hinges I postulated that the delta 3 might exacerbate the flapping by increasing the pitch on an upward flapping blade and decreasing the pitch on a downward.

This is contrary to what Delta-3 is intended for.




Secondly I don't have the engineering background to understand Delta-3s graphs and I can only assume that many of the members of this forum are in the same boat. In a private3 communication from Delta-3 he indicated that in his investigation he determined that the phase angle on the R-44 was 108-degrees. At least that is what I thought he said. I asked him to explain how he arrived at this conclusion and he explained in engineering speak which went over my head.



Please tell me I am wrong. Explaining why I am wrong with technical statements and not vitriol.

This is what I stated in my first post. Maybe I should have added in "not with complex graphs". That way we can all understand the problem.

All of my comments on this subject are based on the kinematics of the R-44 rotorhead and are based on a graph provided by Delta-3. Maybe he can include the graph and we can go from there.

:E :E

[helmet fire]

Almost Lu, almost.
I am springloaded in the about-to-be-amused position.


I:ok:

[Hilico]

Delta3, would you be able to post a similar graph for a 206? This might give us something to compare.

Looking at the graph, it seems assymmetric - though exactly what is assymetric I'm not sure - lift? And if it is lift, why isn't the aircraft rolling left?

[whirlycopter]

Is MR coning not a function of rotor thrust as opposed to gross weight, so in auto configuration the total rotor thrust is massively reduced, thus reducing coning.

That said I didn't really understand Lu's question in the first place.

I'll get me coat.....

[delta3]

To Lu

I must admit it sometimes goes over my head, but then again that is the challenge/charm of helo's it can keep you buzzy for a while.

I really want to try to make sense, but this is perhaps even more challenging then trying to understand it myself.

Fase lags :
gyroscopic precession=flywheel=simple zero excentricity rotor turning in outer space=90°='resonant system'

Real world=not always simple rotors=damping=not resonant
Real world=aerodynamic side effects=not inertial

So fase of a real world rotor is not always 90.
Examples:
For a typical stiff rotor (large excentricity or ridgid joints) the lag will be less
For the R44 (low excentricity non ridgid) with coning and wind it is more

Concerning the coning delta3
It is a dynamic system indeed Lu, but I showed a step responce that is extremely well behaved and fast (less than one rev) , so for all normal disturbances no negative side effects on dynamic behaviour.

I come up with another idea why this could be there : Robinson certainly knows how to reduce designs to the essence, which I would call good engineering practice (Lu you know a lot about maintainability, if I see what a steel plants some of the other rotor systems are...). May be it is by wanting a simple flapping delta3 system he introduced a coning delta3, just because of geometric simplicity, reducing the number of moving parts etc. But this coning delta3 just is an amplifier which can be simply taken care off be adapting the other mechanical (or hydraulic) amplifiers in the overall collective pitch link system. So it is a good approach to simplify mechanically the design.

Continuing to try to make sense....

Delta3

To Hilico

Yes I most likely can, but need to have precise enough data. I don\'t have a 206, but at the heliport I can get the data. Give me some time (2-3 weeks I have to dose the time for this hobby...) Any material is well come (mechanical design drawings of hub, measures, weights, profile, blade twist, this must be reasonably precise, otherwise GIGO)

As far as the assymetry of lift is concerned I worked out an explanation but allow me (sadistically I admit..) to let you guys come up with an explanation (or rebutal..).

Some extra material : the dynamic lift distribution in this case as looked from the front and the right rear (rotor without tip losses) looks like

http://www.e-sign.be/Private/heli/R44_dlift_1POB_100K_F_v3a.jpg
http://www.e-sign.be/Private/heli/R44_dlift_1POB_100K_SR_v3a.jpg

I may try to find a way to have 3d quicktime pictures published on the net (this is what I get, and is very help full when looking into the proposed solutions)

Delta3

To Whirlycopter

you are right about the coning it is a function of trust. In autorot this is however not massively reduced, oyherwise we would fall out of the sky.

Delta3

[Dave_Jackson]

To evaluate the Robinson rotorhead, the first requirement will be to determine whether the two outer hinges are coning hinges (rotate in unison) or flapping hinges (rotate independently).

Is there a venturesome pilot who would be willing to;

~ Remove a coning/flapping hinge bolt, then stick it through a piece of white cardboard and then replace it on the rotor head.
~ Remove the cotter pin from the nut on the other coning/flapping bolt and replace the cotter pin with the innards of a BIC pen.
~ Bend the tip end of the pen so that it's ball is touching the cardboard.
~ Fly the hell out of the helicopter.

http://www.unicopter.com/Temporary/R-22_Hub.jpg

If there is a straight line on the cardboard pointing toward the bolt that is holding the cardboard in place; then they are coning hinges.
If the pen has randomly scrawled on the cardboard; then they are flapping hinges.
If the cardboard, the pen, and the nut are missing; then thank the almighty, whoever she may be, for a safe return.

If the missing nut is the pilot who tried this ridiculous experiment; then the prayers to the almighty must be modified slightly.

Anonymous


I've got to get a real job. :uhoh:

[Hilico]

Delta 3

Please don't spend a couple of weeks of effort! I don't have a 206 either, nor any access to the data you require. It was curiosity pure and simple (I am a very curious chap). I once tried a course in modelling fluid flows - perhaps after this I'll go back to it, as it looked a lot easier.

[delta3]

To Dave

To save on (potential) victims the following thoughts:

- as the blades cone progressively the pen will show the increase from rest to max coning
- if they would flap then they have to go negative, which in view of the hard stops (remeber the not pull down instruction) will create victims even without putting BIC pens to the bolts

The reason/conditions why they are coning is
- The blades are sufficiently equal in weight
- The excentricity is small but not too small so the the centrifugal forces have some leverage
- No unreasonable frictions (bolts stuck or so)

Then
- the centrifugal force will create an equilibrium that makes the hub take the average position between the two blades (try this out on a static model, the centrifugal forces will flatten it so to speak)

Remember centrifugal force are at the root the dominant forces. These forces are equal because any inbalance in centrifugal forces great enough to make the hub unequilibred will be able to shake the heli apart.

Delta3

[Dave_Jackson]

delta3,

I agree. The side hinges are intended as coning hinges. These hinges were probably included to minimize out-of-plane bending moments in the roots of the blades and grips. This probably allowed for a lighter rotor.

Some thoughts.

" - as the blades cone progressively the pen will show the increase from rest to max coning"

My previous posting was not clear enough. Both bolts rotate with their blades, therefore the cardboard and the pen will rotate. It would therefore be possible to see if the rotations were synchronized or out of sinc.


" - if they would flap then they have to go negative,"

Not necessarily. This is a low inertia rotor, therefore under heaving loading the rotor will have a reasonable cone.


" - No unreasonable frictions (bolts stuck or so)"

All three R-22 hinges have a resistance to sliding friction of up to 22 ft-lb., under no load, when initially installed. The bearings appear to be of the sliding bushing type, therefor the breakaway friction will be somewhat higher. [Lu ~ for an unrelated reason, would you confirm that these bearings are actually bushings and not needle bearings. Thanks] . Granted that the static friction under load is very small when compared to the centrifugal force, but under small angle consideration, they will be quite close.

IMHO the concern, if there is one, would be that during an abnormal aerodynamic moment and/or control input the flexible blades may cause the rotor assemble to actually 'flap'. This combined with the delta3 MIGHT prove interesting.

Dave

[[email protected]]

Delta 3 - fabulous diagrams which show a basic problem with flying a helicopter - as you increase forward speed the lift on the advancing and retreating sides of the rotor disc are different and therefore the aircraft will try to roll towards the advancing side. We (brits) call it Inflow Roll, others (Americans) call it Transverse Flow. All that stops it happening is the interference of the pilot who moves the stick towards the retreating side to keep the'wings' level. IIRC the R22 has a little spring/weight combination that reduces the lateral stick force required in cruise flight to ease pilot workload.

[delta3]

To Crab,

To funny thing which took me 3 sleepness nights is that this picture may seem unbalanced, but in fact its fully balanced.

- the proof is of course in the result: the rotor is nicely level as follows from previous published time plots of flapping angle versus time or rotation (I also have a plot of the rotor disk to have a proof of that as part of my reports)

But wat happens, how the understand:

- the total lift diagrams certainly shows a lot of (total) lift on the forward blade
- looking at the distribution one observes that the retreating blade gets all lift from the top while the forward blade gets it from the middle
- why : because of the twist in the blades, when the forward blade flaps such as to reduce lift it gets from the high speeds , the tip gets near zero lift because of twisting. The retreating blade has to coop with a large ineffective area, so it gets all the lift from near the top.
- the middle of the blad has however a far smaller leverage arm than the top, so this is why the rotor, even with those very assymetric pictures is quite in balance.

One thing that triggers my curiousity : the rotor must feel important higher order harmonics:
- tip with large lift alternating with tip with zero or even negative lift
stated otherwise
- center of lift forces shifting all the time from middle to top.

Delta3

[bugdevheli]

Surely they must be only coning hinges as the bearing surfaces are a hardened steel bush running against some form of fibre outer bush. If these areas were subject to continous movement ie once per rev then I think the wear rate would be too great for this type of bearing plus the pivot bolts are tightened to some hundred foot pounds of torque which would suggest they are not designed for a thousand or so direction changes per minute. I think they cone up to accomodate the weight of the machine and any flapping takes place in the form of bending of the blade. I dont suppose anyone has film footage of a Robinson rotor system in action do they?

[Chiplight]

Delta3,

Nice graphs. Especially the delta3 graphs which show that Robinson had good reason to build in the delta3 angle.

I am not sure from reading your posts if you included the effects of flapping in your modelling of lift distrubution.
It seems to me that the disymmetry of lift shown in the graphs is exactly what flapping is supposed to take care of. Flapping will create a cyclical change in angle of attack that should balance the lift across the disc. The graphs don't seem to reflect this.
The massive imbalance shown in the graphs cannot be explained by invoking twist, I don't think. There are numerous helicopters and gyros with untwisted blades that achieve perfect symmetry of lift through teetering rotors.

[Dave_Jackson]

bugdevheli,

The bolts, nuts, journals, and bearings have the same part number for all three hinges. The only difference is a slight length change in the journal and the associated shims.

The teetering hinge bolt is installed with a torque to give the bolt 0.016" - 0.017" of stretch. Unfortunately, I do not have the cone hinge bolt torque value.

Dave

[RDRickster]

For some reason, I couldn't find the Robinson Tech thead (merged), so I'll start a new one.
Yesterday, I received an update for my R44 POH. RHC sent a notice that says:

NOTE: AD 95-26-05 has been rescinded by the FAA. The pages inserted at the ned of Sections 2, 3, and 4 to comply with the AD are no longer required and may be removed.
The page at the end of Section 2 is the R44 Limitations Section and specifies what most of us consider the "SFAR." You know, < 200 hours and/or < 50 R44 hours prohibits flight if winds are > 25 knots or if wind gust spreads > 15 knots. If further goes on to recommend 60 KIAS in moderate to extreme turbulence, provides a few definitions, etc.

The page at the end of Section 3 is is the R44 Emergency Procedures Section and discusses right roll in Low-G conditions, flight turburlence, etc. The short end is to apply gently aft cyclic to reload the rotor and in other conditions do what is necessary to maintain positive G.

The page at the end of Section 4 is the R44 Normal Procedures Section. This provides detailed recommendations concerning factors that contribute to Main Rotor Stall and Mast Bumping. Mostly it recommends keeping your head out of your a$$ when flying and to avoid sideslip and large, rapid forward cyclic inputs, etc... keeping a cruise speed > 60 KIAS.

Now, none of the Safety Notices have been removed and these aren't FAA mandated either. Obviously, these notices were required to be in the POH as part of the AD 95-26-05. My question is, does this mean Frank finally agreed to take the R44 off SFAR requirements (especially wind restrictions relating to hours in type)?

During the last discussion of the SFAR, Frank actually pushed the FAA to continue applying it to the R44 when he really didn't have to. Is this a change in RHC philosophy that is more driven by marketing? Of course, the insurance companies will probably continue to have requirements of their own... especially Pathfinder. Interesting change of events, isn't it? Does anybody have the inside scoop on this?

[bugdevheli]

Dave. It usually takes about 100 ft lbs to get the ammount of stretch specified in the manual. Bug

[delta3]

To Chiplight

You are right, my explanation is probably misleading.

When validating the results, if removed twist to get a different insight. Also untwisted blades display a comparitive behaviour, since the angles of attack are also influenced by the change in speed (for instance forward blad tip also will have smaller angle then middle of blade in case of untwisted blade, because of speed difference). I just used the twist argument to clarify this behaviour, because it makes it more outspoken.

I may try to build up sequences of graphs in an number of cases, but I had/have to be shure the equations were ok, which by now I believe. This will produce lots of graphs (I have more parameters such as mach nr, angle of attack etc).

The goal would be to have some kind of animation with cyclic and collective as input. I do this now point wise : right now load, and speed are the input and the program calculates the rest (pitching or hub-plane angle, cyclic, collective induced velocities etc as input for the detailed dynamic blade model)

The animation will involve extra programming work, that will take time.

Delta3

[bellsux]

Just wondering if anyone else has encountered this before.

On our R44 I found that both upper rear door hinges had cracks radiating from the same area which is about 10 mm behind the pin where the bend starts. Hinges should be checked every 100 hrs but due to one of them cracking underneath the paint it could be very easily missed. If you do check it yourself make sure that you dont use a sharp scraper that will burr over the crack but better still get your maintainer to do it with paint stripper and dye penetrant.

If it does crack all the way through and the door comes off in flight it could really spoil your day. So for this reason I have put in a defect report and notified the manufacturer but the due to the way the red tape wheel turns I thought I would post it on PPrune as a heads up to others. Please PM if anybody has seen it as well.

Thanks.

[EMS K-MAX]

Yeah ive seen it

When dickheads let go of the door in the wind.

[raven2]

Can anybody explain why on the preflight checklist for the R44 that it is not required to check the altenator belt condition / tension.

If I remember correctly this item is listed in the R22 checklist so why not the R44??

Regards

Raven2:confused:

[Grainger]

I would imagine because it's not easily accessible.

Exposed on the R22, but under the rear engine cover on the 44.

You'll soon know if there's a problem when you fire up because of the Alt warning light.

[raven2]

The altenator is easily accessable if you get down and lie down underneath the machine. From there you can easily check the altenator tension and condition.

If you want to properly inspect the “Exhaust system” for “No cracks” you will have to lie down underneath the machine anyway. Or are you expected to view it from the lower cowl door on the right side? If this is the case then you would need a fibre optic camera in your toolbox!

Raven

[WLM]

Hi to our Oz operators

Does anyone know of an approved HF system for R44's? The Sat system is too expensive , about US30,000, so trying to find alternative as we work from sea level with good VHF coverage to zero within 50 nm due to mountain environment. It is not safe specially during our wet season operation
Thanks
WLM:O

[Av8r]

Why can’t you use a new generation Satphone and have it installed just like any other phone? They do come with an external mount aerial. Something like:

http://www.telstat.com.au/comm12.htm

I don’t think they cost much, the calls are expensive, but if you’re just using them for SAR.....

[Giovanni Cento Nove]

There is an aeronautical kit for the Motorola 9500 series phones. Includes a cradle and interface to your ICS and an external antenna etc. Same as an in car kit really. They used to be around USD 3500 then the phone on top which can vary depending where you go. Iridium charge is USD 1.50 a minute from anywhere to anywhere else on the planet regardless of distance. The unit was made by Icarus Instruments in the US who may have moved on to be called Sky Connect. These newer units cost a little more but do offer more with automated flight following, data (low speed text etc) the text is very cheap and could be very useful .
Google - Icarus Sat Talk II or Sky Connect.

[trackdirect]

WLM,

There is a new Qualcom CDMA/SAT that has just come on to the market, works quite well on the globalstar system (vodafone)

Worked most of the way from Alice to the east coast on CDMA a little while back.

[delta3]

Some new examples of the R44 simulator I am building.

Presently I am working on the output..
The program now superimposes the technical results on a 3-dimensional graphical representation of the heli in its position in space.

Still not finished, but some feedback is welcome (especially from pilots/teachers).

If some of you want to use the pictures in classes, feel free, but please reference the author (pm me for that).



Delta 3

http://www.e-sign.be/private/heli/R44_beta_1POB_100K200F_v3c.jpg
--
http://www.e-sign.be/private/heli/R44_alfa_1POB_100K200F_v3c.jpg
--
http://www.e-sign.be/private/heli/R44_dlift_1POB_100K200F_v3c.jpg
--
http://www.e-sign.be/private/heli/R44_lift_1POB_100K200F_v3c.jpg

[LGNYC]

This is really cool!
The third graph, is it total lift? Isn't it rather the coef of lift? If I am reading it correctly I see a huge amount of lift on the tip of the retreating blade, which might be a little surprsing.

Can I ask you, what software are you using ? Mathematica or something like that?

LOG

[delta3]

To LGNYC

The third is indeed lift coefficient (I called it distribution) Remark (Red) Titles are on top.
I will edit post to separate the pictures.

Sofware used is MatLab.

Delta3

[WHK4]

delta3

Have you tried using cylindrical coordinates?

[rotaryman]

Hi there fellow Rotorheads,

Would anyone have a R44 spread sheet for the R44 Weight & Balance.

Exel i guess would work......

Thanks in advance................Safe Flying and have a Great Christmas were ever you may be....:ok:

[WLM]

Try the following site
www.christchurchhelicopters.co.nz
Cheers
:cool:

[rotaryman]

WLM

Many thanks for the info, it was exactly what i was after.

Have a Great Christmas

:ok:

[WLM]

Slinging

What is the official approved load for a Raven, and do you anybody selling a second hand unit?

Cheers
WLM ;)

[DennisK]

Hughes 300C

I wonder if I can ask the knowledgable Lu Zuckerman or another similarly qualified engineer to give an opinion on the series of cluster failures which affected the early Hughes 300's. Serial number 570 and prior.

I think it is common knowledge that the year 2000 failure to my son's Hughes 300C was one of a series of such failures to the part number 234 (left hand) cluster. (clevis lug) The UK AAIB reported it was the seventh such failure since 1972. In fact my own researches uncovered two more making nine in all.

My question is ... at what point should the certifying authority, (in this case the FAA) have effectively grounded the type and mandated the replacement of the later part no 234-3 ?? ... instead of continueing with the policy of releasing ongoing Ad's, SB's LTO's etc. Following the first occurrence, the second, the fifth sixth or at all.

Earlier this year, this mod was mandated and I trust that all the affected airframes have been modified. I'm sure that the position is well known in the UK, but as time goes on and people change, things get forgotten. I know for sure there are some relevent airframes lying around in hangars which one day may be brought back into service. A point well made by the AAIB's report.

The draft report cited two of the causal reasons for my son's accident as. "Failure to mandate the fitting of the modified cluster etc .... combined with an over reliance of a strategy of repetitve inspections .... etc.

But just to return to my question. At what point would this industry consider a responsible certification authority should act once it became apparent that the issued AD's etc were not proving effective ?? A big question indeed. Any help so much appreciated.l

[Bomber ARIS]

Dennis

Your posting deserves to be a thread in its own right.

(This is the only time I've viewed this thread and that was only because I clicked the wrong box)

This is a matter that affects us all and would benefit from input from the PPRuNe "big guns", and maybe some lurkers out there too.



Bomber

P.S. Please don't tell anyone you saw me on an R44 thread!

[chopperchav]

Read about this company in New Zealand who make the helipod for Robinson choppers. Sounds like a great idea considering lack of luggage space.
Any chance of them coming to the UK. I would buy one tomorrow.

[Genghis the Engineer]

Out of interest, is this a general problem with smaller helicopters?

G

[helicopter-redeye]

Have you got a link to more info

?

[chopperchav]

Check out following site:

http://www.helipod.co.nz/

[helicopter-redeye]

Looks like theres a picture of one bolted onto a G Registered R22 in green and gold, so is it CAA certified for the UK?

(and does it go on a 44)?

NB the 'seeder' looks fun. I could do the lawn at the same time as building flying hours ...

:{



edited, as I read on it says United Kingdom CAA AAN certified. Would not fit an R44 with float system though.


edited again (teach me to think on my feet without reading to the end). Says R44 in development "..Due to the limited number of R44 ships in service at this time we anticipate that this installation will for the time being be accomplished as an individual modification to the aircraft under approval of a local modification and Form 337"

Whats with the 'limited'? Almost as many R44s in the UK as 22 now. Does anybody out there have one?

h-r

[Genghis the Engineer]

Odds are that a CAA AAN will apply to only one type - the R22. But, in these brave new days of EASA, it should automatically apply to any R22 in an EASA state.

Wouldn't be too hard to organise approval on an R44 I'd have thought, particularly if there's an FAA STC for it.

G

[kissmysquirrel]

These pods have been out for a while now. I remember seeing them some time ago.

Just out of interest Helicopter-Redeye, does KUKI helis still use G-REDI?

[Whirlybird]

Out of interest, is this a general problem with smaller helicopters?


Is lack of luggage space a general problem? Yes. I can't think of any small (ie 2 or 3 seater) helicopters that really have any.

Or, do you mean the related, and in my view more serious problem, of using under the seats in the R22 to store stuff? The seats are designed to collapse in the event of a hard/crash landing, but it you put things underneath....well, you don't need it spelled out, do you? :eek: And is this a problem in other small helicopters? I'm not sure. The Rotorway has no storage space in the cockpit whatsoever, I don't think the Schweizer 300 does, and I'm not that familiar with any others.

So for the R22, I think this helipod is a brilliant idea. :ok:

[Wildwilly]

chopperchav

I work from the same location as Helipod NZ as a flight instructor although am not involved with the company.

Over 700 Helipods have been manufactured to date, for both R44's and R22's. The last container-load sent to the USA sold within 10 days of it's arrival into that country and there are now over 100 in use in Canada.

The R44 Helipod is FAA certified and the company is currently processing EASA validation for Europe. By all accounts and from what I've seen here, the pods are very strong and well built although still light. Aerodynamically there is minimum effect - to the degree that relatively low-time pilots wouldn't even notice the difference in flight characteristics from a 'clean' profile.

They definately seem to be the answer to the age old question "Where do I put all my gear?" I too am hesitant about putting too much crap under the seats and thereby compromising the ability of the seats to do their job absorbing impact forces.

E-mail the owner at the following address if you need more information as what I've written above is about all I know!:ugh:

[email protected]

Regards.


PS - Helipod website is a bit dated now so a few things have changed and more Helipod versions are available.


PPS - helicopter-redeye;

R44 Clipper version of the Helipod is currently under development so not available just yet

[helicopter-redeye]

Thanks Wild W. These pods would help with carrying the Clipper wheels as they will not fit properly under the back seats.

I'm also worrying about the gas bottle under the left seat now, in the event of a hard landing. Note to self. Always sit on the right ...

:(

[Wildwilly]

...quite right. Gas bottle under seat might be good for a nice quick vertical exit through the cockpit roof, but then an even quicker decapitation...hmmmm...not a good look. Keep it clean and in the green...

[helicopter-redeye]

Still it is an FAA/ CAA approved piece of aircraft equipment. It inflates the floats ...

:{ :{ :{

[Choppersquad]

About to purchase an R44 Raven 1 or 2. Can anyone tell me what is the resale value on a Raven 1 versus a Raven 2 as everyone who has flown both machines is telling me there is no difference flying either in the UK as the raven 2 was not designed for this weather. 3 years from now will anyone want raven one,s ,comments if possable.

ps. raven 2,s sept delivery raven 1,s april from today.

[RDRickster]

2001 Raven w/ 583 hours on EBay with a Reserve starting bid of $260,000 found here...

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=63680&item=4517993519&rd=1&ssPageName=WDVW

Raven I prices aren't fetching as much these days, especially the early models without hydraulics. Raven II commands high price and waiting list until RHC brings the second factory online. With ISO certification, it could be a while before it is in full production to meet demand. You may find a good deal on a Raven with hydraulics and that might suit you very well. Raven II only gets you 40 more pounds of payload and a little better performance (100 pounds more lift, but the blades way 60 pounds more - so it is really only 40 more pounds). Oh... just to clarify, I have no idea who the seller on EBay is... just giving my 2 cents. Also, I probably wouldn't purchase an aircraft from EBay, but the link has the seller's phone number... so, you should be able to arrange an inspection by your A&P. Of course, since you live in Ireland, that may change your purchase methods!

[helicopter-redeye]

It will have something to do with you selling something that somebody else wants to buy (especially with delivery lead times for new machines).

The Raven 1 is still a good machine with the original Lycoming engine and a lot less to buy then the 2.

Also if the machine you are selling has something special (i.e. pop out floats or it's an IFR trainer).

That being said, there are a lot of R1 and R2 machines in UK&I now so demand and supply are more balanced than when the hydraulic machines came out in 2000.

Check out Helidata Classified for resale prices in UK&I.

http://www.helidata.rotor.com/


It's the non hydraulic machines that are absolutely in trouble in price terms now IMHO. It is possible to pick one up for less than the price of an R22 (and not a new one).

The real question is how any of the prices will change if Robinson move to a different engine type to address the AVGAS question over time. A diesel running J A1, now that would change the game.

Also, if Robinson were to focus much/ all of their production capability on the R44 at the expemse of the R22, then there would be an uptick in demand for Ravens for training schools, which may rebalance prices a bit.

No hard and fast rule, depands on age/ condition/ hours/ salesmanship of seller/ equipment on board/ colour (of machine)/ etc

[Choppersquad]

thanks helicopter red eye
looked at a 25 year old 206 but think i will stick to the ravens.
i think i will go for the r2 as i feel the r1 will not be the easy machine to get rid of at a good price 3/4 years from now .but in saying that 46k extra is a lot extra when making up the funds for the r2.

[helicopter-redeye]

Buying the most recent product usually a safe bet (until the next release)

good luck

h-r

[HeliHunter]

Boys & Girls,

Anybody have or know of anyone with an R44 in the QLD area that might be available for a long term cross hire - Astro preferred.....

Send me a PM if you have anything.

Thanks

[helicopter-redeye]

Just out of idle curiosity on a Saturday evening before dinner, why "prefer" the Astro?



:ouch: (in anticipation)

[HeliHunter]

Consistency & cost...... !

Hope you enjoyed your dinner !!

HH

[belly tank]

What type of ops would the machine be doing?

[headsethair]

Just out of interest : http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&category=63680&item=4519897717&rd=1

[Choppersquad]

hi all
can any owner 206 operators tell me the hourly cost of a 206 111 based on approx 175 hours per year usage.
if possible has anyone also looked at the operating cost of
a r44 raven 2 based on its life span taking into consideration
its overhaul at end of life.
Some pilots will tell you are better buying a old jet ranger and paying for componants as they come up,the age of the machine will insure you are at its lowest cost when purchasing the machine insuring you do not loose as much when selling it versus r44 for half what you paid for a new one.
hopfully some one has operated both to settle the mind on the matter.


regards
choppersquad

[Cross-eyed]

If your willing to pay for an excellent model that will answer your question and more both Conklin de Decker (includes helicopter cost database) and SLM (in my opinion, has a better model) offer solutions. Both consider residual value.

Conklin is at: http://www.conklindd.com/cgi-bin/softcart.exe/store/lcc.html?L+scstore+rkpf4610ff7dd87d+1107062294

SLM is at: http://www.aircraftcostanalysis.com/

I have used both but have not stake in either so I hope I'm not breaking any forum rules.

[Choppersquad]

thanks cross-eyed i will look into this,but there must
be a 206 owner on the forum who can give me
a idea .as we all know when turbines go wrong
it hurts the pocket.some one must have gone from a
turbine to a piston machine due to operating costs
who can settle this dicussion.

regards

cs

[Aesir]

I operate B206B and I find that the Bell published Direct operating cost is pretty accurate @ $200.- pr/hr.

The DOC does not include insurance, hangar, crew compensation & financing.

But the R44 is probably cheaper although I have not much experience with the R44 (only R22!) but comparing these two is comparing apples and oranges, they´re not really in the same class if you want to operate them commercially in my opinion.

Its like people often compare the B206B with the AS-350B2 which really competes with the B407.

I guess the B206B should be compared to EC120 really! and I know that the JetRanger will be cheaper and more reliable than the EC120 although the JetRanger will make more noise.

But for a cheap to run personal helicopter I´m sure the R-44 is fine.

[paco]

I know about 10 years ago, it was approx 80,000 pounds per year to run a 206 privately, meaning roughly 250 hours a year - if it was 60,000 one year, it would be 100,000 the next, so the figures were quite accurate.

We operate here on around 200 per hour, but our machines do 600 hours per year on commercial basis.

Phil

[helicopter-redeye]

I did the comparison a while ago for by business plan, so I'll post it when I can find in in the next day or so, - 206 -v- R44 (NB, the R44 won)

h-r

[206 jock]

If you want to keep your machine for your own use and don't need the 5th seat, I'd say the R44 R1 is the machine for you. I'd recommend that you ignore anyone's view on DOC on a 206: the reality is so tied to component times and - frankly - luck, that what the papers say and what you find in reality will be different.

I bought a 206, primarily as I wanted to lease it back to a commercial operator to contribute to operating costs (and keep the VAT-man off my back!). But frankly it's cost me a fortune in the last three years with unexpected repairs and components due. But I've had a good run for the last few year (touch wood), but with a turbine wheel due in a few months, who knows what horrors will come to light when they take it out!

But no doubt, the R44 will depreciate, where the 206 will hold its value - but be warned that the value of a 206 is more closely asscociated with component time than age.

Personally, I love the 206 to fly - it is better than the R44, but whether it's worth the difference is open to debate.

[Aesir]

I guess I have been lucky with the B206 I' ve flown or operated, but unscheduled maintenance has been pretty much non-existent, except for the *:mad: :* Janitrol heater, although right now, "Knock on wood" it works fine.

However "Choppersquad" you asked for operating cost based on 175 hr/yr. Those cost depend alot on the insurance, hangar cost, crew etc.. just figure around 200 USD pr/hr, or if you are in the UK on 200 Sterling, to be on the safe side and if you have unscheduled maintenance its just your bad luck, its really impossible to estimate the unscheduled maintenance required!

You dont really say if the aircraft is for commercial use or private? If for private then you cant go wrong with a Robinson, but commercially then:

http://valfell.4t.com/images/flysmart_logo_jpg.jpg

[Choppersquad]

thanks guys
helicopter/red eye it would be great if you posted the info
on the costs 206/r44 if you find same.

cs

[helo_44]

Hi all....last week I had to (at great expense to management :mad: ) replace the ring gear on my Raven 2 after just 250 hours.

Sitting alongside were two other Raven 2s undergoing the same surgery.

The engineers put the high failure rate down to an incorrect starting procedure used by most pilots.....basically beginning to feed in mixture BEFORE releasing the starter button.

I am a little sceptical and would be interested in feedback regarding:

- experience with with incidence ring gear failure around the traps and if it is higher on Raven 2s than other machines,

- technical thoughts on the explanation offered.

Thanks!

[Lu Zuckerman]

To: helo_44


What Robinson has told you may very well be correct but three failures for the same reason on three helicopters in the same area (Improper starting procedures). Gears fail for many reasons one of which is abuse and overstress. However they also fail due to improper machining (A lot of S-58 T tail rotor gear boxes failed for this reason). Other gears fail due to faulty heat-treat where the gears are either too hard or not hard enough. (There were 43 B-214s that had bull gears that were too soft and had premature wear). There is such a thing, as batch sensitivity where parts are made at the same time and if one has a problem then there is a strong possibility that the other parts made at the same time will have the same problem.

When the gears are removed if you can check the manufacturing date to see if they were made at the same time. Even if they were not made at the same time have your maintenance engineer check the wear pattern and the Brinell hardness of the gear body.


:E :E

[chopperchav]

I've got a raven 2 with 18 hours on clock. I have found that on starting, the blades will start rotating with clutch disengaged. Im putting this down to the clutch belts being tight as it is still very new. Is this normal or should I be getting something done?
Consequently it can be a **** to start and I find myself with the starter button pressed with mixture full in as the drag of the blades keeps stalling the engine. Am I doing some damage to my ring gear by doing this then? What is ring gear anyway?

[Choppersquad]

you might post correct start up on the 44 if you have spoken to
robo on this matter.

cs

[helicopter-redeye]

I have found that on starting, the blades will start rotating with clutch disengaged. Im putting this down to the clutch belts being tight as it is still very new. Is this normal or should I be getting something done?

POH, "Blades turning within 5 seconds"

On a 600hr Raven 1 they turn very early on as well and the engineers say that this is correct.

New R44's can be a bit difficult to start but settle down within about 70hrs. It's then a case of throttle management during the clutch process to ensure it does not stall as the belts tighten.

I've found 62% engine tach reading by the time the belts are going tight gives a smooth start (POH is 50- 60 with clutch light on) but this has also varied between machines (56 - 63 range) and also if it is the first start of the day or the sixth.

Also recall it was harder to start all engines in Maryland, USA, but this may have been because it was much colder outside ...

[Vfrpilotpb]

The mighty Ford Corporation had a very costly time in the early 70's and then the 80's with the ring gears of many Capri 1600 and 2litre engines ring gears failures, and as Lu has already said it was the heat treatment of the teeth making them not hard enough, the secret in starting equipment is to make the smallest and least costly piece of kit the one most likley to fail, Ie the starter pinion should be the weakest item, ring gear next and then engine last.

Vfr

[chopperchav]

Helicopter- redeye, the problem I am having is blades turning with clutch switch 'disengaged'.

[headsethair]

"Helicopter- redeye, the problem I am having is blades turning with clutch switch 'disengaged'."

Easily fixed with a phone call to Wycombe and a little visit to their workshop........it's a belt thing.

[helicopter-redeye]

Correct, on start up (as you turn the key/ press the button in RII) the blades turn. As the engine lights, before you throw the brown guard switch, the blades will be turning about 1 rev per 2 secs.

I'm told that this is normal and expected (the engine likes load). Older machines (& I recall most of the Astros I ever flew) this did not happen.

I've just had a new clutch actuater fitted (the springs lost springiness on the original) and the blades noticably turn more as it is new (engineer says this is fine too).

Check with your engineer if uncertain or if the clutch is not disenganging correctly. 50 to 62 seconds on the timer from switch to clutch light on depanding on usage.

[chopperchav]

Thanks for the info, glad that is normal.

[CRAZYBROADSWORD]

You will find that blades often turn when you start if the aircraft was shut down the day before on a warm day then left overnight in the cold. try engaging then disengaging the clutch before you start the thing up as this should put the belts back to the right tension.

[helo_44]

Hmmmmm....lots of stuff here....but the missing bits seem to be:

What is a ring gear - a gear (usually attached to the flywheel area) that the starter motor engages with to turn the crankshaft of the engine during start up

What happened before/after failure - since close to new and during start up the starter motor would occaisonally fail to engage with the ring gear. this made a sound like high pitched whizz...rather than the usual aruuuugha during a normal piston engine start.....usually stopping the start procedure and waiting about 30 secs remedied the situation.....this happened more frequently until the engine failed to start at all.

What happened - the ring gear had big chunks out of the side of it and rounded teeth in some parts...I will try to recover the failed gear and get some pics....as a matter of interest one of the machines being repaired was from Brisbane....a long way from Sydney so with different pilots....

What is the required starting procedure - of course this is in the manual....but my take on it is (check this with your engineer!!!)

Main switch on
Area clear
Throttle closed
Mixture full rich
Prime (cold engine 6 secs, warm engine 3 secs)
Mixture full lean
Press starter button on collective with left hand
As soon as engine fires release starter button
Quickly feed in mixture to full rich with right hand
Alternator, clutch, oil pressure, etc

The important thing (according to my engineer) is to ensure that the starter is released BEFORE feeding in the mixture rich lever.....

I am still interested if anybody else has had similar issues as I am having difficulty understanding how the damage I obsered was caused by the starting sequence.....

PC

[Gaseous]

Lots of experience of ring gear failure with Enstroms. Mine is on its seventh. (its 29 years old). Looking through the log books it has been a problem all its life so its not likely to be pilot induced or a batch production problem. Enstrom is Bendix fuel injected with Bendix mags which I think is the same as a Raven 2. Enstrom starting procedure exactly as described above.

I assume the R44 uses 2 sets of contact breaker points.

Mode of failure is ususally when the engine doesn't fire until the instant the switch is released. What then happens is that the advanced cb points are then activated causing the engine to fire. If there is not enough momentum to carry it over TDC, the engine will rapidly revolve in reverse for half a revolution. If the starter motor gear is still egaged, something breaks. Ususally its the ring gear but can be the starter motor casting. Ive even had it chew up the sprag clutch in the starter motor.

The next time the starter is tried there is a gnashing of gears. Very unpleasant.

As the starter drops out of mesh with the ring gear pretty quick, it can only happen if the button is released at exactly the moment the advanced points open. This is why it doesn't happen very often.

There is an unauthorised fix for this by putting a switch to hold the retard points on until the engine is actually running but as far as I know there is no authorised fix for this.

Its worse for helicopter engines than fixed wing as the belt drags a bit and there is arguably less flywheel effect. (no prop)

I don't believe it is a problem of wrong starting procedure. It happens if you are unfortunate enough to release the starter at the wrong time, which you have no way of knowing. Crap design.


You gotta live with it.

Gear failure can also be caused if the relay that switches to to retarded points fails but that is not likely in a new 44.

Pushing the start button with the engine running is not good either.

[Lu Zuckerman]

TO: helo_44

You were addressing the starter ring gear on the engine. I thought you were addressing the transmission. My statement still stands and it applies to the engine ring gear as well as the gears in the transmission. Now that I know what you are talking about I have to agree with the starting techniques being the culprit. However faulty manufacturing processes can also effect the gears longevity.

:E :E

[Doucheman]

As a quick question, is there any particular reason that an R44 couldn't do a barrell roll given that it is a 1G positive manouvre??
Look forward to your input
Thanks
Douche

[moosp]

I'll start with a couple of reasons why not.

1) It is against the POH and therefore against CASA regulations and therefore illegal.

2) You WILL crash.

[Flight Safety]

It's unthinkable with a teetering rotor head (the R44). Only possible with a fully articulated or semi-rigid rotor head.

[Gomer Pylot]

Perfectly done, it's theoretically possible. But not with me in the aircraft, or anywhere near it.

[Flight Safety]

Gomer, yes, it's theoretically possible. But unlike the fully articulated and semi-rigid designs, there is no margin for error with the teetering rotor head. The execution would have to be textbook perfect, which is not likely on your first (and last) attempt.

I'm with you, I'd be out fishing that day.

[Gomer Pylot]

FS, theoretically possible and practically possible aren't the same thing. While it is theoretically possible to do it in an R22, trying it is only for the terminally stupid who play in the shallow end of the gene pool. Like I said, it won't be attempted if I'm in the aircraft.

[Vfrpilotpb]

Seems this will help to increase sales of R44's, and give PPL(H) pilots a bad press!

DON'T DO IT! will be a bad end to your exciting day

Vfr

[212man]

Why do people keep repeating the myth that a barrel roll is a 1 g manoeuvre? Think; how do you depart straight and level flight to commence the initial climb and, then, how do you pull out of the final dive?

I agree it is not (or does not need to be) a high g manouevre, but it does require more than one to be pulled.

[2beers]

Well, there is a margin, but not much. Not much at all...

Since it is a teetering rotorhead, it will need positive G during the whole manouvre, so one (not me!) could pull 0.5g over the top so not to loose too much height. The problem with this is that the responsiveness in the helicopter deteriorates, since it need the helicopters weight to pull on the rotordisc to respond. Less weight, less response - 0g no response, at least to my knowledge. There's been a 206 doing a barrel-roll due to stupid parachutists, having the same rotor construction principle and limitation.

The dynamics of aerobatic flight is very interesting and a good discussion would definately bring up a few learning-points on the design of a teetering rotorhead and other designs. And an understanding of why the POH says no to such things. Sometimes it's a design limitation other times a rule-limitation.

Saying that a barrel-roll is a 1g manouvre, shows a lack of understanding of the manouvre. First you have the pull-up, the more you pull it into the vertical, the more g you can pull over the top and keeping it positive. The interesting part is that if you pull it up too much, there's no energy or speed left for you to work with over the top. If you on the other hand don't pull it up far enough, you will probably see the ASI-needle pass the redline twice, and having to pull lots and lots of g's at the bottom.

From a teetering rotorhead point of view, I'd guess a split-S with a low speed entry would be better, but then, if you survive the first part, the obvious risk of overspeed is another thing to contemplate.

This is all in theory. Myself after competing on international level aerobatics in planks, I've never rolled a Cessna or Piper. I know they can do it, but they aren't built or certified to do it, so I don't. Horses for courses.

Bottom line is that if you have the experience and skill to perform it flawlessly, you also have the experience to never attempt it. If you don't have the experience to make it, it WILL be the last experience. And insurance premiums rises for everybody else.

Now get me that BO-105! :E


/2beers

[Floppy Link]

stick a empty fuel drum on its side
hover taxi towards it
use the downwash to roll the barrel

then you can truthfully say you've done a barrel roll in a R44
Just don't try the aerobatic version!

:ok:

[212man]

Really? silly me. I shall have to berate my old ab-initio FW instructor (A2 QFI) for incorrect gen. Even Neil Williams seems to have got it wrong too, then!

[2beers]

An easy way to look at the barrel roll:

If you take a flat gift-wrap string and make a loop with it (looks lika loop) and then pull the ends apart until the string is straight, there will be a 360deg twist on it (roll). Everything in between is a barrel roll.

Too easy! ;)

If you now take the ends and tie a knot instead, it's a snap-roll or lomcevak, depending on the knot-tieing skills. :ok:

As a final show: Take a pair of scissors and cut the string (and maybe your fingers) in multiple small pieces and suddenly you have a R44 doing a barrel-roll :E


/2beers

[warpig]

you can prove on paper that a 44 or even a 22 can do a loop or barrel roll but doing it is another story

[Rotorbee]

Famous last words:
I wonder if ..... ?
Watch this!!!
I'll show you somthing.
Do you think that thing could do ......?

To find out, you could buy a shiny new R44 and install radio controll equipment and then we could all watch from the ground if that would work out. You could even program all the control inputs. PM me, when you are ready. I want to see the crash, too.

:E :E :E :E

[fluffy5]

In theory sounds fantastic,yet then I woke up :\ .
Leave the throwing around to the proper bits of kit .
areobatics for the plank pilots normal vfr civil choppers leave well alone.
sets a not particular good note for a ppl,new shiny chopper and the wrong attitude.........look what i can doooooooooooo?:{
Another point what operations manual civil choppers do allow you to do areobatics any takers,but I bet there are not many if any?

[IntheTin]

Why would you want to barrel roll a 44? Its easier to jump off a high building if you want to kill yourself! :ouch:

[Capn Notarious]

Maybe some kind person with a massive computer and CGI software might do this. Then we could all see it and stay alive. Gravity is okay it's the sudden stop.

[Doucheman]

thanks for the input, to cut a long story short, an aerodynamics arguement between colleagues led to debate on the theoretical possibility. Have since also heard rumors that it has been done in an r22? Am wishing i had of chosen another name than doucheman after having the dictionary meaning explained, but been a work nickname for too long. Thanks again

[Teignmouth]

Don't know about an R44, but I know of a Bell 407 that did a loop and roll at an air show in South Africa.

See http://hagar.up.ac.za/christo/Bell407Loop.wmv

Far as I know, the aircraft has been grounded ever since.

[leemind]

and this was debated at great length in an earlier thread... see The Great Loop Debate (http://www.pprune.org/forums/showthread.php?s=&threadid=137278&highlight=407+roll)

recommended reading for doucheman :ok:

[delta3]

1. I have seen quite some years ago a 206 do it, so yes, it is possible. But NO you should not do this (I'll try to find out if the pilot is old and bold....)

2. Same old story as before about my R44 simulator : it really starts working well, but it takes quite some time to learn to fly with it . This looks more difficult than the real thing, you only have visual clues. I also approach it off-line, that is create sec by sec control sequences that I playback, but that takes time...

Up to now I stick with hover, landing, take-off, autorots etc and validiate standard enveloppes. Of course loops etc are tempting, and this is btw of course the first things my kids want to do with it, but so far margins seem incredibly thin and they seem to crash...


Computer used : standard (uptodate) PC.

Delta3

[rotorfan]

I remember reading somewhere on Rotorheads about an R22 rolling, airborne, not on the ground. (When? What thread? Dunno. Too many late nights ppruning, like right now...) If I remember correctly, it sounded like a low-G tail rotor-coupled roll. :ooh: Somehow the pilot survived, and Frank R. couldn't wait to talk to the lucky SOB. :cool:

[krobar]

It doesnt stand for RRRollling. That rotor head starts to do some funny things once the load ain't pointing down anymore.

[The Rotordog]

Yes, this thread has been done before. But apart from the inadvisability of such shenanagins, why do people say such things cannot be done? Of course any helicopter can be looped and/or rolled, no matter how many (or few) blades it has. The various laws of nature are not suspended simply because we do not like the airframe or it's attached rotor system.

[SASless]

Well Rotordog....old trusty partner....shuck about 80 pounds and rent a 22 and put on a demo for us. Same construction as the 44 , more plentiful and a lot cheaper, thus easier to replace should theory and reality take divergent paths (along with some rather sensitive bits). We could watch a video tape of yer demo by remote computer....no need for solid overhead cover that way thus not as difficult logistically.

If you were to invite the IMAX crew done...we could slow the film speed way down....watch the blades as they twist, scoop, tuck, dive, warp, feather and all that....and see just how the dynamics work out. Think of the fame that would await you here.....with accolades from all around.

[2beers]

Since everybody knows that helicopters actually can't fly, the big thing is to get them off the ground. Once that has been dealt with, it shouldn't take more skill to actually roll it, should it? :cool:
For people lacking that skill, a good dynamic rollover with lots of bouncing around should count as a roll but then the guy or girl inside would need a low level endorsement/waiver first :E