exceeding POH take-off speed
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You two are into a clash of culture FAA V EU on windsheer along with your talking about different things.
There is a rule of thumb out there that you take some factor of the mean speed and third of the gust and add it onto approach speed and Vref. This comes from high momentum aircraft, large fan engines with a slow spool up time. Now this stipulated in the aircraft manuals that you need to add it. The performance manuals have taken this into account and it has also been tested.Unfortunately this has dropped down the aircraft classes and people are doing it to low momentum fast response engine machines. Which don't require it and isn't included in the manuals and hasn't been tested.
The result is aircraft are trying to land with 30-60% more energy than the designer had envisaged. Which causes other issues. My work type there is no requirement to add it and its an up hill struggle to get the practise stopped because it leads to a heap of other issues related to getting raped in the flare and performance issues and also a vastly increased maintenance bill.
Which is what I think PACE is on about which may or may not be in his aircraft manuals for his work machine to add the additions.
F900 eX is on about your in the poo your going down due windshear usually microburst not just a change in direction/speed and there is nothing you can do about it. Which you pitch to just below/on stick shaker don't change the configuration and max power. Then hang in there until you either crash or recover.
Which is the EU method for all aircraft and is also used by airbus and Boeing and the other big jets.
Now the smaller TP types under FAA there is mixture of theory's out there some pilots have been trained to get rid of the drag flap and go for Vyse. On the basis that the drop in height you get removing the flap is more than made up by the additional performance gained by loosing the drag.
Some also say the same for putting the gear up.
There is a rule of thumb out there that you take some factor of the mean speed and third of the gust and add it onto approach speed and Vref. This comes from high momentum aircraft, large fan engines with a slow spool up time. Now this stipulated in the aircraft manuals that you need to add it. The performance manuals have taken this into account and it has also been tested.Unfortunately this has dropped down the aircraft classes and people are doing it to low momentum fast response engine machines. Which don't require it and isn't included in the manuals and hasn't been tested.
The result is aircraft are trying to land with 30-60% more energy than the designer had envisaged. Which causes other issues. My work type there is no requirement to add it and its an up hill struggle to get the practise stopped because it leads to a heap of other issues related to getting raped in the flare and performance issues and also a vastly increased maintenance bill.
Which is what I think PACE is on about which may or may not be in his aircraft manuals for his work machine to add the additions.
F900 eX is on about your in the poo your going down due windshear usually microburst not just a change in direction/speed and there is nothing you can do about it. Which you pitch to just below/on stick shaker don't change the configuration and max power. Then hang in there until you either crash or recover.
Which is the EU method for all aircraft and is also used by airbus and Boeing and the other big jets.
Now the smaller TP types under FAA there is mixture of theory's out there some pilots have been trained to get rid of the drag flap and go for Vyse. On the basis that the drop in height you get removing the flap is more than made up by the additional performance gained by loosing the drag.
Some also say the same for putting the gear up.
Last edited by mad_jock; 22nd Jan 2014 at 07:07.
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gawd stuff me. talk about lost the plot.
there are two speeds of interest to a pilot at takeoff.
the minimum stall speed is a speed below which you cant fly.
if you takeoff at just over this speed as you rotate the aircraft slows slightly and you touch wheels again.
do that in a cross wind and with the aircraft skewed into wind in some aircraft and that is a recipe for an aircraft destroying ground loop.
in those more critical aircraft there is a 'takeoff safety speed' beyond which you will most assuredly establish a positive rate of climb and not be at risk of touching the wheels on again.
a typical takeoff safety speed is stall speed times 1.3
you can work it out yourself.
can you take off faster than that?
wheel hub strength and tyre rating are the limits that come to mind.
most aircraft tyres in lighties are rated to 120mph.
takeoff safety speed is the minimum speed advised not the maximum.
make sense?
there are two speeds of interest to a pilot at takeoff.
the minimum stall speed is a speed below which you cant fly.
if you takeoff at just over this speed as you rotate the aircraft slows slightly and you touch wheels again.
do that in a cross wind and with the aircraft skewed into wind in some aircraft and that is a recipe for an aircraft destroying ground loop.
in those more critical aircraft there is a 'takeoff safety speed' beyond which you will most assuredly establish a positive rate of climb and not be at risk of touching the wheels on again.
a typical takeoff safety speed is stall speed times 1.3
you can work it out yourself.
can you take off faster than that?
wheel hub strength and tyre rating are the limits that come to mind.
most aircraft tyres in lighties are rated to 120mph.
takeoff safety speed is the minimum speed advised not the maximum.
make sense?
My ASI tells porkies on the take-off roll so I've learnt to ignore it.
Too busy tap dancing on the rudder pedals and looking where I'm going.
Can't remember when I last glanced at anything other than RPM.
Edited to add... It lifts off with full power at below the indicated power off stall speed.
Too busy tap dancing on the rudder pedals and looking where I'm going.
Can't remember when I last glanced at anything other than RPM.
Edited to add... It lifts off with full power at below the indicated power off stall speed.
Last edited by Flyingmac; 22nd Jan 2014 at 07:45.
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F900
I may have used the word loosely and would have probably been better using the words strong wind conditions where you are likely to experience all of the mix of wind direction vertically and horizonatlly of air masses and pockets.
Pace
I may have used the word loosely and would have probably been better using the words strong wind conditions where you are likely to experience all of the mix of wind direction vertically and horizonatlly of air masses and pockets.
Wind shear itself is a microscale meteorological phenomenon occurring over a very small distance, but it can be associated with mesoscale or synoptic scale weather features such as squall lines and cold fronts. It is commonly observed near microbursts and downbursts caused by thunderstorms, fronts, areas of locally higher low level winds referred to as low level jets, near mountains, radiation inversions that occur due to clear skies and calm winds, buildings, wind turbines, and sailboats. Wind shear has a significant effect during take-off and landing of aircraft due to its effects on control of the aircraft, and it has been a sole or contributing cause of many aircraft accidents.
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How is it possible for any so called school to teach such absolute rubbish to students?
What this particular school is trying to do, is to teach airline operations to their students. In a perfect world they would do so in an actual airliner, such as a B737 or A320.
Unfortunately using an airliner for ab-initio training is pretty darn expensive. That's why they are using SEP aircraft instead of airliners. But that's not the same as trying to teach someone to fly a SEP aircraft.
In fact, AFAIK on most integrated courses students don't even do a SEP exam. So at the end of their training they don't even get a SEP class rating.
As an aside, did you know that there was an option available for the PA-28 "gear down and welded" Cadet/Warrior, that would add a mock gear lever to the panel? Green lights and all. It was extremely annoying to fly in aircraft fitted with these, since the green lights would blind you during a night flight, but if you "raised the gear", an alarm would sound upon deploying flaps or something. In the end we just pulled the CB to disable the system altogether.
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Backpacker that's the issue.
they are trained to fly a commercial jet.
They are licensed to fly everything.
If they were banned from flying the stuff they are clueless about and haven't been taught properly how to fly there wouldn't be a problem. And there wouldn't be this dragging down of flying standards in the GA world.
I agree.
the problem is these high momentum slow spool types SOP's are being taught from the word go to the commercial students as shown by the guff that was posted from a commercial school in Sweden. These pilots then can't get a job and get an instructor rating and teach the same guff to PPL's.
And then people wonder why there are so many runway excursions, nose legs broken, engines shock loaded, PPL's struggling to go solo, etc etc.
Pace the effect on aircraft is completely related to the aircrafts momentum and by momentum I mean its resistance to change.
A light aircraft when encountering Windshear will virtually instantaneously arrange itself into the new conditions. Something big will take seconds if not 10s of seconds.
So this good airmanship additions to approach speed and landing speed are a complete load of bollocks with anything under 5 tons. In fact they are a load of bollocks with my 7 ton type pref A type as well.
they are trained to fly a commercial jet.
They are licensed to fly everything.
If they were banned from flying the stuff they are clueless about and haven't been taught properly how to fly there wouldn't be a problem. And there wouldn't be this dragging down of flying standards in the GA world.
this has absolutely no relevance whatsoever to a light piston single operation , a bit like Boga's post of complete bollocks, people dragging larger aircraft idea's into light aircraft operations.
the problem is these high momentum slow spool types SOP's are being taught from the word go to the commercial students as shown by the guff that was posted from a commercial school in Sweden. These pilots then can't get a job and get an instructor rating and teach the same guff to PPL's.
And then people wonder why there are so many runway excursions, nose legs broken, engines shock loaded, PPL's struggling to go solo, etc etc.
Pace the effect on aircraft is completely related to the aircrafts momentum and by momentum I mean its resistance to change.
A light aircraft when encountering Windshear will virtually instantaneously arrange itself into the new conditions. Something big will take seconds if not 10s of seconds.
So this good airmanship additions to approach speed and landing speed are a complete load of bollocks with anything under 5 tons. In fact they are a load of bollocks with my 7 ton type pref A type as well.
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dubbleyew, sorry mate but that's bollox. I can hoink the Chippie into the air in the 3-point attitude at a speed way below that at which it'd fly with the power off, and drag it along just above the surface way out on the back of the drag curve. As we accelerate in ground effect one can feel the wing 'come to life' as the AoA moves to min drag and beyond. Then we can climb away normally. This is quite usefull on very boggy strips.
In normal ops one gets the tail up ASAP and lets it fly off when it's ready, x-wind or not!
In normal ops one gets the tail up ASAP and lets it fly off when it's ready, x-wind or not!
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Dear Original Poster:
There is no good reason for keeping the plane on the ground too long. While it may look "COOL" for a quick pull up, it is just someone playing ''spitfire ace" or something like that. Well, let me take it back, if you planned on doing an aileron roll right after takeoff, it might be useful. But then again a cherokee isn't authorized for acrobatics/aerobatics.
I once had a student checkout for someone claiming hundreds of hours in a piper seminole. On a very short strip he held the plane on the runway until blue line (single engine best rate of climb) speed PLUS. AS the dyke or is it dike, at the end of the runway looked quite solid I took over and Pulled up. Circled the field and landed. I told the student/checkout he had never flown the seminole and to get off the field. Honestly a nut job.
ASSUMING you are capable of using your hands and feet normally and have not intended to exceed demonstrated crosswind component, you should take off at normal speeds or so. Otherwise you use too much runway. The reason I mention hands and feet normally is that some people are convinced extra speed allows them to use less deflection of controls. And to some extent they are correct. However, the controls if fully deflected should produced the same result as the test pilot's. Using higher speeds means the controls are required to move less, giving a false comfort to those reluctant to put the pedal to the stop, etc.
I've seen some things written here about landing and additives to vref. We use half of the steady state wind and all of the difference between the steady wind and gust (called the gust factor), so wind 20 gust 40 would be
10 plus 20 equals 30, but NOT TO EXCEED adding a total of 20 knots to vref. IF you have to add more than 20, consider waiting or diverting.
On larger types, holding forward yoke during the start of the takeoff roll is normal to improve nosewheel contact, however as the plane accelerates it is removed.
One more bit of information,not asked for: there is a rule of thumb that if the steady wind, even right down the runway exceeds half the stalling speed in the takeoff or landing configuration (as appropriate), you might want to reconsider flying. We usually call it a day at 60 knots in larger types.
Before I knew this rule, I have landed a PA28 arrow in 50 to 60 knots wind. Ground roll quite short, hands quite full, including to the stops.
Remember, if you are too fast, your nose is too low and you might want to see the new video involving the jet crash at aspen, colorado, USA.
There is no good reason for keeping the plane on the ground too long. While it may look "COOL" for a quick pull up, it is just someone playing ''spitfire ace" or something like that. Well, let me take it back, if you planned on doing an aileron roll right after takeoff, it might be useful. But then again a cherokee isn't authorized for acrobatics/aerobatics.
I once had a student checkout for someone claiming hundreds of hours in a piper seminole. On a very short strip he held the plane on the runway until blue line (single engine best rate of climb) speed PLUS. AS the dyke or is it dike, at the end of the runway looked quite solid I took over and Pulled up. Circled the field and landed. I told the student/checkout he had never flown the seminole and to get off the field. Honestly a nut job.
ASSUMING you are capable of using your hands and feet normally and have not intended to exceed demonstrated crosswind component, you should take off at normal speeds or so. Otherwise you use too much runway. The reason I mention hands and feet normally is that some people are convinced extra speed allows them to use less deflection of controls. And to some extent they are correct. However, the controls if fully deflected should produced the same result as the test pilot's. Using higher speeds means the controls are required to move less, giving a false comfort to those reluctant to put the pedal to the stop, etc.
I've seen some things written here about landing and additives to vref. We use half of the steady state wind and all of the difference between the steady wind and gust (called the gust factor), so wind 20 gust 40 would be
10 plus 20 equals 30, but NOT TO EXCEED adding a total of 20 knots to vref. IF you have to add more than 20, consider waiting or diverting.
On larger types, holding forward yoke during the start of the takeoff roll is normal to improve nosewheel contact, however as the plane accelerates it is removed.
One more bit of information,not asked for: there is a rule of thumb that if the steady wind, even right down the runway exceeds half the stalling speed in the takeoff or landing configuration (as appropriate), you might want to reconsider flying. We usually call it a day at 60 knots in larger types.
Before I knew this rule, I have landed a PA28 arrow in 50 to 60 knots wind. Ground roll quite short, hands quite full, including to the stops.
Remember, if you are too fast, your nose is too low and you might want to see the new video involving the jet crash at aspen, colorado, USA.
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We use half of the steady state wind and all of the difference between the steady wind and gust (called the gust factor), so wind 20 gust 40 would be
10 plus 20 equals 30, but NOT TO EXCEED adding a total of 20 knots to vref. IF you have to add more than 20, consider waiting or diverting.
10 plus 20 equals 30, but NOT TO EXCEED adding a total of 20 knots to vref. IF you have to add more than 20, consider waiting or diverting.
Have you worked out what the additional energy you have added to the aircraft by doing this.
Work it out for Max landing weight you might be surprised.
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http://flightsafety.org/files/alar_bn8-2-apprspeed.pdf
while I would always differ to the specific aircraft manual for advice on additives, I refer you all to the above.
madjock, yes my aircraft manual says to do the above as I have listed. Half the steady, and all of the difference between steady and gust. NOT TO EXCEED 20 knots.
This is industry standard. Our FAA POI and our company have used this for years.
Tailwinds are not used in calculation.
Certainly if your manual, approved by the FAA/CAA says something else for your plane, that takes over.
while I would always differ to the specific aircraft manual for advice on additives, I refer you all to the above.
madjock, yes my aircraft manual says to do the above as I have listed. Half the steady, and all of the difference between steady and gust. NOT TO EXCEED 20 knots.
This is industry standard. Our FAA POI and our company have used this for years.
Tailwinds are not used in calculation.
Certainly if your manual, approved by the FAA/CAA says something else for your plane, that takes over.
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F900 and MJ
I have landed a business jet on 4 occasions with winds of 40 gusting 70 (yes 70kts)
On the approach the ASI was leaping plus and minus 15-20 kts are you both suggesting if ATC wanted you to drag in for spacing from 8 miles you would happily fly VREF?
MJ you often quote light aircraft as being little different to other types yet claim they are completely different here.
Also if you have 30=40 its headwind component on your Heathrow length runway are you really going to worry that much about your inertia? What would that do to your stopping distance?
I think I would be more worried about slamming into the runway when I am hovering over the stall and catch a large downdraught or being in a very bad situation on the approach
Pace
I have landed a business jet on 4 occasions with winds of 40 gusting 70 (yes 70kts)
On the approach the ASI was leaping plus and minus 15-20 kts are you both suggesting if ATC wanted you to drag in for spacing from 8 miles you would happily fly VREF?
MJ you often quote light aircraft as being little different to other types yet claim they are completely different here.
Also if you have 30=40 its headwind component on your Heathrow length runway are you really going to worry that much about your inertia? What would that do to your stopping distance?
I think I would be more worried about slamming into the runway when I am hovering over the stall and catch a large downdraught or being in a very bad situation on the approach
Pace
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I seem to have created quite a future sharing my practical experience of PA 28 and Trinidad flying in strong gusty cross winds. I do follow the POH guidance contrary to popular opinion on here. However I have found from practical experience that in very strong and gusty crosswinds the aircraft can become airborne in a gust and then settle back in a very hairy position at around 55 to 60kias, which is also close to 60 kts ground speed. This is seriously tricky on a narrow runway.
I have found that if one nudges forward very slightly on the yoke then the aircraft won't fly under those circumstances it just becomes a little light and can be kept straight with aileron and rudder (nose wheel steering) input. A positive rotation 5 to 10 KIAS above normal take off speed then gives a reliably quick and permanent departure from terra firma.
The aircraft can then be cleaned up while tracking the runway heading with a suitable drift angle which can easily be 20 degrees under these circumstances.
With a PA 28 or Trinidad fully loaded there's easily enough runway at Alderney for this to work.
I shall now sprint for hills and hide behind a suitable rock.
I have found that if one nudges forward very slightly on the yoke then the aircraft won't fly under those circumstances it just becomes a little light and can be kept straight with aileron and rudder (nose wheel steering) input. A positive rotation 5 to 10 KIAS above normal take off speed then gives a reliably quick and permanent departure from terra firma.
The aircraft can then be cleaned up while tracking the runway heading with a suitable drift angle which can easily be 20 degrees under these circumstances.
With a PA 28 or Trinidad fully loaded there's easily enough runway at Alderney for this to work.
I shall now sprint for hills and hide behind a suitable rock.
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I'm talking about take off not landing. For landings I fly the book speeds and crab down to about 200 ft or so then transition to wing down onto the centre line. For cross winds adding much of a gust factor is asking for trouble you have to be quick on the throttle and ready to around if you get sudden sink.
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No I wouldn't, but feel free to show me where I have suggested doing that in a biz jet, we have been talking about about light aircraft in this discussion, you suggested applying a gust factor correction to Vref in a light aircraft I.E bringing larger aircraft techniques and applying them to small aircraft.
Ok we will talk light aircraft! We have runway 27 winds 300/25 gusting 40
you are flying a PA28 6 miles out on final how would you fly that approach?
You do have shear on the approach and across some hangers?
pace
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exactly the same way as I would flying with the wind calm.
Exactly the same speeds and also configuration for landing as well.
As I have said I have done 27G39with 15knts of xwind in a tommy with all manner of ****e coming off the hills from the south.
You just fly the correct attitude the issue with momentum has nothing to do with runway length.
And gusting 70 really isn't anything strange if you fly into Shetland regularly. Again in the work machine normal speeds and full flap landing way more than 4 times. Those shetlanders have to get there sunday sport you know.
And momentum is a completely different thing to inertia.
This is the nub of the problem. People think that excess energy helps. But the aircraft won't stop flying until exactly the same energy state what ever wind its in. So by giving it more energy to get rid of you just expose yourself longer nearer the ground to anything mother nature throws at you.
Exactly the same speeds and also configuration for landing as well.
As I have said I have done 27G39with 15knts of xwind in a tommy with all manner of ****e coming off the hills from the south.
You just fly the correct attitude the issue with momentum has nothing to do with runway length.
And gusting 70 really isn't anything strange if you fly into Shetland regularly. Again in the work machine normal speeds and full flap landing way more than 4 times. Those shetlanders have to get there sunday sport you know.
And momentum is a completely different thing to inertia.
I think I would be more worried about slamming into the runway when I am hovering over the stall and catch a large downdraught
Last edited by mad_jock; 22nd Jan 2014 at 18:35.
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Pace
I would add 12.5 knots for the steady and 15 knots for the gust, but as this equals 27.5 knots, I would only add the 20 knots to vref as we are NOT TO EXCEED 20 knots additive.
I've not calculated the x wind component nor do I know the limits.
ask the other guy what he would do flying a tomahawk at 70 knots on final with the wind 80 knots right down the runway
I would add 12.5 knots for the steady and 15 knots for the gust, but as this equals 27.5 knots, I would only add the 20 knots to vref as we are NOT TO EXCEED 20 knots additive.
I've not calculated the x wind component nor do I know the limits.
ask the other guy what he would do flying a tomahawk at 70 knots on final with the wind 80 knots right down the runway
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I went back twice to make sure
Pace indicated the steady wind was 25
the gust was 40
last time I checked half of 25 was 12.5 is
and 40 minus 25 is 15 (this being the difference)
25 plus 12.5 equals 27.5. and NOT TO EXCEED 20 knots additive.
so I don't know where you get 7.5 for anything.
Pace indicated the steady wind was 25
the gust was 40
last time I checked half of 25 was 12.5 is
and 40 minus 25 is 15 (this being the difference)
25 plus 12.5 equals 27.5. and NOT TO EXCEED 20 knots additive.
so I don't know where you get 7.5 for anything.
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I do fly jets for a living and have not flown props for well over 25 years.
So, I called up a friend who is a current CFI and asked her opinion , asking specifically for any FAA stuff from her last CFI clinic.
She said there isn't anything by regulation and that just the other day she added 20 knots to her PA28 on final at KMDW due to wind.
Now, I know two things.
ONE: half of 25 is 12.5
Two: it is up to the pilot using all resources to determine the right speed for landing...POH, MANUFACTUER's info, local knowledge of turbulence/etc
and I'll add my 20 knots like I said.
IF the airfield is very short, I might reduce my speed on very , very short final or as the wind changes, but this is something that would take considerable time to discuss.
So, I called up a friend who is a current CFI and asked her opinion , asking specifically for any FAA stuff from her last CFI clinic.
She said there isn't anything by regulation and that just the other day she added 20 knots to her PA28 on final at KMDW due to wind.
Now, I know two things.
ONE: half of 25 is 12.5
Two: it is up to the pilot using all resources to determine the right speed for landing...POH, MANUFACTUER's info, local knowledge of turbulence/etc
and I'll add my 20 knots like I said.
IF the airfield is very short, I might reduce my speed on very , very short final or as the wind changes, but this is something that would take considerable time to discuss.
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dear f900x
if you actually read the document, which I just pointed out to show you that there were other ways of thinking, you would see the phrase :SUCH AS
(not limited to).
my original post stands as half the steady and all of the difference between gust and steady, not to exceed plus 20. none added for tailwind.
IF you google wind additives to vref, you will find many things, if you read what I posted with link there is even another way of doing it involving another two methods.
However, I stand by my original post.
if you actually read the document, which I just pointed out to show you that there were other ways of thinking, you would see the phrase :SUCH AS
(not limited to).
my original post stands as half the steady and all of the difference between gust and steady, not to exceed plus 20. none added for tailwind.
IF you google wind additives to vref, you will find many things, if you read what I posted with link there is even another way of doing it involving another two methods.
However, I stand by my original post.