Vectors for the ILS

[IO540]

Unless you are doing a coupled approach in which case you will never get GS capture.

I think intercepting the GS from above is dodgy.

If you are really sure you are just above the GS, you can uncouple the autopilot and push the yoke down hard and hope to get an intercept and then fly it by hand, or even re-engage the AP, but it is a bit tacky.

I have been vectored above the GS a few times; the last time was Bournemouth. But to be fair it could have been avoided by me doing a really rapid (-1000fpm or faster) descent to the platform.

[VMC-on-top]

If you are told "cleared for the approach" then you are cleared to immediately descend to the platform altitude and fly the approach as published. This is true worldwide, including the UK

So is it possible that you ask for vectors to the ILS but are given "cleared to approach" instead? - implying that you fly the procedure instead - or would the instruction be more explicit?

[aluminium persuader]

VMC -
Not in the UK. On contact you will either be told what type of approach to expect or asked what type of approach you require. A commercial operation will invariably want whichever will get them down with minimum delay, however people can require all sorts of different things for training/currency purposes.

If there is any shadow of doubt, just ask for clarification.

[Roffa]

Unless you are doing a coupled approach in which case you will never get GS capture.

I think intercepting the GS from above is dodgy.

Intercepting the GP from above is the norm at larger airports where CDAs are expected to be flown by just about anything that makes a bit of noise.

Possibly irrelevant to TB20 ops but, given intercepts from above happen hundreds/thousands of times every day, it mustn't be too dodgy.

[IO540]

So is it possible that you ask for vectors to the ILS but are given "cleared to approach" instead? - implying that you fly the procedure instead - or would the instruction be more explicit?

This could happen only outside the UK, but no, if you are being vectored you would not fly the published procedure. You would intercept the localiser when you get to it.

If ATC English is suspect (true much of the time in southern Europe) it is best to help them out by e.g. reporting "localiser established". In Spain, if ATC did not understand something you said they ignore the call (presumably as it leaves no evidence against the ATCO on the tape) and they ignore the call even if you repeat it.

Remember that in all flight, the vertical and horizontal clearances are separate. So, cleared for such and such SID is the lateral clearance, cleared to climb FL090 is the vertical clearance. Unless otherwise specified on the plate

But when you are "cleared for the approach" the two clearances merge; you can descend to the platform and fly the approach as published, vertically and laterally. In the UK, the phrase is used only for non-ILS approaches.

What has confused me, in Greece mainly I think, is being told "report ready to commence the approach". What exactly is that?

Intercepting the GP from above is the norm at larger airports

Sure but only from just above the GS, where the GS indication is not right off the scale If you get vectored so the GS is off scale, you must go missed.

BTW Roffa a TB20 can fly the ILS at almost the same speeds as a 737. Once, in Prague, the GS was 210kt (descent + tailwind) and ATC told me to slow down. I do have to slow down a bit more at the end though In the UK, most big-airport ATC is not used to mixing light singles with big jets because of the £500 landing fee.

[Sir Niall Dementia]

LV;

Have a go at Plymouth sometime when Plymouth Mil are keeping you at FL40 and the glideslope is off the bottom stop. Last time I asked to be re-vectored and the mil controller seemed surprised. He certainly struggled with the concept that you shouldn't intercept from above and the approach would be very far from stable.

SND

[IO540]

What about all the stuff "we" learnt in the IR, about multiple false glideslopes which exist above the real one, and on which the GS indicator indicates in reverse i.e. an UP indication actually means you have to go down?

That's why one should not intercept a GS other than as published, or if doing a CDA then one needs to make sure the angle of descent is close enough to 3 degrees to ensure the instrument indication is well within limits for the last few miles.

[Local Variation]

Regarding capturing from above in my previous post, we are talking about no more than 500ft above the cleared height in most ocassions, so no big deal as far as I'm concerned.

I'm sure we've all be trained the same irt false glideslopes.

My point was more to do with the a/c being at a position where both aspects need to be captured at around the same time due to be vectored in early to intercept the loc.

That for me can be the most challenging part of taking vectors for an ILS approach.

That is, of course, aside from using the NDB hold and approach

SND;

Flew into Plymouth City last month, albeit on a visual pattern. Great night out though.

[tmmorris]

Flew two ILSs yesterday after not doing one for a couple of months - rust really setting in!

First was procedural (Cambridge). Second was radar vectored back at home base. What it did get me thinking though was that in IMCR training because we trained to the IMCR ILS DH of 500ft, we flew the ILS at 90kt to keep up with traffic and didn't make any configuration changes until after the decision point. On NPAs we flew the entire approach configured for low level circuit (75kt/2 stages flap - all this in PA28 btw) to reduce workload on circling approaches.

As a result I'm unable to change configuration on the ILS approach without starting to 'lose it' with the trim change.

What do others do in similar ac flying to lower minima - fly the approach slower (i.e. take the config change at GS intercept, which is when I slow to 90kt) and hold up the other traffic, or cope with the config change at say 500ft just before decision height?

Tim

[IO540]

The simplest way is to fly it on the autopilot. Then you fly as fast as you can or want onto the localiser, slow down to intercept the GS at the gear limiting speed (130kt for me), and then gradually bring back the power so as to be at the landing flap limiting speed (about 100kt for me) at the DH. With the drag of the full flap, one can slow down from 100kt to the landing speed even if one gets visual at just 200ft, without engine management issues because the power setting (and the CHT) is quite low at that point.

One can do the same flying by hand but obviously it needs more concentration...

The above offers the greatest respect for fast traffic following behind.

In really crap conditions, knowing the approach is likely to be to minima, it is easier to configure earlier. In that case, perhaps fly the localiser at 90kt; dropping the gear and 1st stage flap at the GS intercept should give you a -500fpm descent (on most IFR SE types) but still 90kt (no trim wheel change) and then you go full-flap when visual.

The most extreme case I know is a circling approach to 20, off an NDB/DME to 02 (flown using the GPS OBS mode, obviously ) at 800ft, with a hill very close on the right. In this case I configure to landing i.e. about 85kt and gear down full flap when flying level prior to breaking off to the right, so the circling turn involves nothing more than a big power reduction and the left descending turn to a landing. But in that case I will still be doing 120kt+ up to the base turn.

IMHO one should never fly procedures really slowly e.g. 70-80kt because of the small margin above Vs and a lack of control authority.

[BillieBob]

My point was more to do with the a/c being at a position where both aspects need to be captured at around the same time

Why would you accept such a sub-standard service from ATC?

[IO540]

Why would you accept such a sub-standard service from ATC?

Substandard or not, it is common enough.

Are you not an IFR pilot, Billiebob?

[Local Variation]

I doubt ATC will see turning a PA28 in at 6 miles as sub-standard. I'm sure they have genuine reasons and given the location, I guess flow has something to do with it, including departures.

I have no complaint, just saying it is sometimes tricky to deal with. Given time and experience, it will become a non-event.

Regarding the question about flaps and DH. My advise would be to keep working at applying before DH. That is what I'm doing now with variable success.

I was trained until the latter part, to go clean to DH. Towards the end, the Instructor had me introducing flaps (PA28) around 1000 ft on the ILS with full configuration just after DH. You need to be prepared for the initial bounce up to kick in (elevator down to maintain the glide) and then look for the drag to have it's effect. I don't mess about trimming. This is fine touch handling as you are now very close in and the glide is super sensitive. Any major increase in power to counter the drag taking you under the glide will see the needle move sharply down and you could be facing a G/A. The local Experts tell me it's more about elevator control than power.

I would say the easy way is to apply the config after DH. If you really want to develop and tune your flying skills, then introduce the config before DH and enjoy very high levels of satisfaction in taking the a/c fully established to the threshold.

What's this about an Auto-pilot ?

[Kerling-Approsh KG]

How many runways are equipped with ILS and also too short to land a PA28 clean?

[thing]

The worrying thing about all of this speaking as someone who is considering taking his PPL next year is that no one seems to know what the score is. Or should I say everyone knows what the score is but it's different to everyone else...I've noticed this in several threads, everybody's opinions seem to differ on what seems to me to be quite important safety subjects. Does anyone in GA actually have a handle on what goes on?

[reportyourlevel]

billiebob, simultaneous localiser and glidslope intercept is not a substandard service - in fact at my airport our largest commercial operator is now asking us to do it like that for all of their flights.

From the point of a radar ATCO (or at least this one!) the shorter the final for a slow(er) aircraft the better. I'm lucky in that for one of our ILS approaches I can descend you below the platform level by a few hundred feet to make sure you're below the glidepath at the FAP (6 miles in this case), but this is not always the case.

[Kerling-Approsh KG]

thing,

You're quite right. Lots of blather and hardly any facts, from people who really should know better... A disappointment.

Shall we start, then, with the over-arching document?

Read extracts from it, and about the role poor vectoring played in the causes of the Turkish Airlines accident on approach at Schiphol in the official report here:

http://www.onderzoeksraad.nl/docs/ra...TA_ENG_web.pdf

The relevant section starts at page 54.

[IO540]

The worrying thing about all of this speaking as someone who is considering taking his PPL next year is that no one seems to know what the score is. Or should I say everyone knows what the score is but it's different to everyone else...I've noticed this in several threads, everybody's opinions seem to differ on what seems to me to be quite important safety subjects. Does anyone in GA actually have a handle on what goes on?

There just is very little standardisation of operating procedures in IFR GA. The airlines have done it, and the (mainly) western ones have used it to achieve a very high standard of safety, but in GA there is a lot of variation.

Aircraft technical capability varies a lot. E.g. I can fly an ILS on the autopilot down to 200ft (legally) but the AP will not capture the LOC or the GS if you are flying a diverging trajectory (laterally or vertically, respectively) at the moment you engage it in the APR mode. This is apparently not unusual, I am told, even in airliner autopilots. If you get vectored above the GS, you may have to do some aggressive hand flying (towards the ground) to get established.

IR training is very basic and mostly still stuck in the 1960s or 1970s. It is done by banging a few well worn routes (true for both FAA and JAA) and you train for the lowest common denominator in avionics etc.

Different pilots develop different preferences. Some like to land with only half (takeoff) flap if the runway is long enough. Nothing wrong with that, except that (on mine) not using landing flap disables one of the two gear-up warnings (the throttle position being the other one) and a good number of Americans (where they have long runways) have indeed landed a TB20 gear up.

And ATC don't always get it right.

Re the Amsterdam crash, I am not going to read all 228 pages (having read a lot of it previously) but was ATC really relevant to it? As the main cause is clearly

The crew failed to recognise the airspeed decay and the
pitch increase until the moment the stick shaker was activated. Subsequently the approach to stall recovery procedure was not executed properly, causing the aircraft to stall and crash.

i.e. the pilots were barely inside the cockpit. The ATC angle is given as

A turn-in, whereby interception takes place at between 6.2 and 5 NM, with no instruction to descend to an altitude below 2000 feet is in deviation of the International Civil Aviation Organization guideline specifying that the aircraft must be flying level on its final approach course before the glide slope is intercepted

which is interesting nevertheless and I wonder how many countries have filed a difference on this, to enable CDA approaches

Due to the fact that the localizer signal was intercepted at 5.5 NM from the runway threshold at a altitude of 2000 feet, the glide slope had to be intercepted from above. As a result, the crew were forced to carry out a number of additional procedures, resulting in a greater workload. This also caused the landing checklist to be completed during a later moment in the approach than standard operational procedures prescribe.
...
As a result of intercepting the glide slope signal from above, the incorrect operation of the autothrottle was obscured for the crew.

Do they mean that if the aircraft was forced to level off, prior to GS intercept as usual, the pilots would have noticed the AT failure? I am not so sure, as they were not paying attention to anything much.

[belowradar]

On the subject of false glideslopes....

Yes they do exist but you should be monitoring distance against height as a cross check (thats why the GS height is given at various distances on the plate). You should definitely know where your DA is in relation to distance from runway

For example "passing 1500ft 2 miles to run looking for 300ft at 0.5dme"

I see a fair number of pilots at renewal who can tell me the Decision Altitude but have no idea where it is as regards distance.

[BillieBob]

simultaneous localiser and glideslope intercept is not a substandard service

As a matter of fact, it is. The standard (in the UK at least) is set down in MATS Part 1 - "Except when Continuous Descent Approach (CDA) procedures are in operation or in an emergency, aircraft shall be positioned so as to maintain a period of stabilised level flight before commencing descent on the glide path, on descent profile of a pilot interpreted approach, or on the nominal descent path of a SRA."

Not to allow a period of stabilised level flight before commencing descent does not, therefore, meet the required (note the use of the word 'shall') standard and is, consequently, sub-standard.