PAPI guidance below 300 ft
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When I did base training on B732 it was a company or UKCAA requirement to achieve an acceptable approach and landing with VASI off. The technique was similar to that taught at flying school. Now there's a coincidence????
Later I flew the line and indeed there were some minor Greek islands where there were no lights, and even if there were VASI's the sun obliterated them anyway.
Later I flew for an operator that forbid approaches with no glide slope guidance. This became a problem to an airport with an NPA and PAPI's on maintenance. Then it became a captain's day only landing with full VNAV FMC guidance. It was still the case night landings with no glide slope guidance we're forbidden.
If the company considers its pilots to be so incompetent and incapable I wonder what other skills are lacking.
How can this most basic of manoeuvres be considered so difficult? All this talk of PAPI's below 300' etc. You shouldn't need the things below 500' on a visual approach if you're capable. OK if you pop out from an NPA at 600' it is comforting to have PAPI's; even more if they are 2W2R. I get students wanting to G/A with 3 reds at 200'. Guess what; as you go around they become 2W2R for a split second, but then it's too late.
Later I flew the line and indeed there were some minor Greek islands where there were no lights, and even if there were VASI's the sun obliterated them anyway.
Later I flew for an operator that forbid approaches with no glide slope guidance. This became a problem to an airport with an NPA and PAPI's on maintenance. Then it became a captain's day only landing with full VNAV FMC guidance. It was still the case night landings with no glide slope guidance we're forbidden.
If the company considers its pilots to be so incompetent and incapable I wonder what other skills are lacking.
How can this most basic of manoeuvres be considered so difficult? All this talk of PAPI's below 300' etc. You shouldn't need the things below 500' on a visual approach if you're capable. OK if you pop out from an NPA at 600' it is comforting to have PAPI's; even more if they are 2W2R. I get students wanting to G/A with 3 reds at 200'. Guess what; as you go around they become 2W2R for a split second, but then it's too late.
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I agree. My company's guidance and the one we trainers push is ignore PAPI and/or ILS G/S below 200ft. The landing is a visual manoeuvre based on runway aspect. Besides, at major airports frequented by heavies the PAPI are set for the greater eye-height so in a 737/320 you will see 3 reds anyway below 300ft when on the correct flight path to the TDZ aiming point. Furthermore chasing the fairy lights below 200ft risks de-stabilising the approach and increases the chance of a firm arrival or a long landing beyond the TDZ. The latter is undesirable on a short runway with obvious risks. Piratepete talks of maintaining v/s of 700ft/min. That is incidental and we certainly do not tell trainees to chase the v/s. Just look at the TDZ aiming point, keep it 1/3rd of the way up the windscreen, be at the right attitude and speed and you will be on a 3 degree slope. In my aircraft (320 series) when the FDs are deselected the FPV serves as an accurate flight path indicator and it's use is strongly pushed. As far as the ILS G/S is concerned, if it's not a CAT3 installation with the LVO protections in place you should not be referring to it below CAT1 DA.
Last edited by Wingswinger; 21st Jun 2015 at 08:05.
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For the airbuses it's a clear cut deal as per FCOM:
Do not follow PAPI or TVASI guidance below 200 ft if the published MEHT is
below the recommended PAPI or TVASI MEHT. Then there's table
A332 - 52 ft
A333 and A343 - MEHT 51 ft
A 345 - 55 ft
A346 - 53 ft.
Agree with the old and proven strategy, simply look outta window and fly.
Do not follow PAPI or TVASI guidance below 200 ft if the published MEHT is
below the recommended PAPI or TVASI MEHT. Then there's table
A332 - 52 ft
A333 and A343 - MEHT 51 ft
A 345 - 55 ft
A346 - 53 ft.
Agree with the old and proven strategy, simply look outta window and fly.
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It's a very interesting discussion, and leads to a broader one, about the meaning of stabilised approaches.
Wingswinger, above, mentions de-stabilising the approach by chasing the lights or the v/s in the late stage. Newer pilots will probably only know about "stabilisation criteria" being a set of numbers and conditions which are to be met, and maintained.
20 years ago an approach which was steadily and consistently 30 feet low, would not have been seen as unstable (although during base training on the 732, I was criticised for allowing 3 reds at <200 to become 4 reds at<100. Well if you maintain the correct approach angle that is what will happen. I didn't argue).
From 300 feet, even with 3 reds, you are going to hit the tarmac. 30 feet vertical error is about 700 feet of runway.
From the trainer's perspective, or even the normal line captain who has to sign in what's left of the aircraft, I'd much rather see no correction to a slightly low late final than yank-and-float. 4 whites might be a different matter, but it's too late to save it with a stuka dive by then.
Local effects also come into play, eg at Corfu, where a 3.5 slope on the NPA meets 3.1 PAPI. And less objectively at a runway where you "know" that the house thermal over the car park will punt you 50 feet up.
That, I suppose, is when you have to do some of that old fashioned "pilot s**t".
Wingswinger, above, mentions de-stabilising the approach by chasing the lights or the v/s in the late stage. Newer pilots will probably only know about "stabilisation criteria" being a set of numbers and conditions which are to be met, and maintained.
20 years ago an approach which was steadily and consistently 30 feet low, would not have been seen as unstable (although during base training on the 732, I was criticised for allowing 3 reds at <200 to become 4 reds at<100. Well if you maintain the correct approach angle that is what will happen. I didn't argue).
From 300 feet, even with 3 reds, you are going to hit the tarmac. 30 feet vertical error is about 700 feet of runway.
From the trainer's perspective, or even the normal line captain who has to sign in what's left of the aircraft, I'd much rather see no correction to a slightly low late final than yank-and-float. 4 whites might be a different matter, but it's too late to save it with a stuka dive by then.
Local effects also come into play, eg at Corfu, where a 3.5 slope on the NPA meets 3.1 PAPI. And less objectively at a runway where you "know" that the house thermal over the car park will punt you 50 feet up.
That, I suppose, is when you have to do some of that old fashioned "pilot s**t".
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I also find that pilots who pay too much attention to VSI displays, fairy lights and attitude displays at low level do not pay enough attention to what their backside is telling them. You correct for x-winds by instinct and feel, often making the correction before the effect has taken effect: if you know what I mean. The same is true for the vertical bumps & humps that mother nature puts in our paths.
Glad the hear someone talk of 'house thermals'. I briefed an arrival, with ILS, on a hot hot day into a dusty area, reasonable headwind, with slightly rising ground inside the OM. I suggested the PF take gear a little earlier to avoid the a/c accelerating as he pushed down to maintain the glide slope with the balloting a/c. The ah ha moment was a joy as he told the story of exactly this happening the week before when taking gear at the usual close in point aiming for a 500 stable point. The bucking bronco was a handful. Much cursing & swearing. It was only JUST achieved with frisky neck hairs.
The house thermals this week over Montmin & Annecy were a joy: if you know what I mean.
Glad the hear someone talk of 'house thermals'. I briefed an arrival, with ILS, on a hot hot day into a dusty area, reasonable headwind, with slightly rising ground inside the OM. I suggested the PF take gear a little earlier to avoid the a/c accelerating as he pushed down to maintain the glide slope with the balloting a/c. The ah ha moment was a joy as he told the story of exactly this happening the week before when taking gear at the usual close in point aiming for a 500 stable point. The bucking bronco was a handful. Much cursing & swearing. It was only JUST achieved with frisky neck hairs.
The house thermals this week over Montmin & Annecy were a joy: if you know what I mean.
I always found the motorway on final to CIA 15 a particular joy in August for the same reason. Massive lift, power off, nose down, then at around 100ft the lift fairies occasionally just disappear requiring a handful of power and a firm yank. Keeps you on your toes 
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Indeed, especially as the PAPI's bring you over the threshold at 80'. It's bizarre; on glide all the way down; looking good, and the last 300' go haywire as you see the touchdown point migrate too far into the RWY. This really is one where you need to keep the crash point fixed in the screen.
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RE-INVENTION
Not because im any sort of expert but because in xxxxxxxxxx im required to train very low hours young pilots to heavy jet type rating first in the SIM followed by base training PPCs (yes a full PPC in a real a/c to obtain the initial type rating) ive had to re-invent myself as an instructor and first deconstruct in my head how to fly visual one engine and two circuits, touch and goes, and go-arounds etc IN AN EFFECTIVE MANNER.Focusing on a steady V/S coupled with keeping the aim point in the correct position works very well for landings in the SIM but things are much harder in the real world with all the thermals, wind effects etc.Bottom line- keep it simple, and dont over-analyse. Its a visual exercise FFS.
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Improper Use of Aids?
What am I missing? I've read the inquiry several times and it simply does not compute. Here's why: For non-ILS approaches, the properly aligned PAPI is a great aid. However, it seems to me that at levels as low as 200' agl, the pilot should be looking at the rwy, not the PAPI. If, by the time s/he reaches about 200' - 300' agl, but cannot clearly see the rwy, the Go Around procedure should already be in process. I do not know the lowest effective height agl for PAPI, but by 200' the touchdown spot should be the only focal point or, again, the Go Around already in progress.
Go, what am I missing? A lower agl threshold certainly may be appropriate for a low/slow airplane like a C172, with a landing/stall speed of well <<100Kts. But, for a large transport, landing and well >>100kts, it is simply too late for the PAPI to be on any real value. Straighten me out guys! Thanks.
Go, what am I missing? A lower agl threshold certainly may be appropriate for a low/slow airplane like a C172, with a landing/stall speed of well <<100Kts. But, for a large transport, landing and well >>100kts, it is simply too late for the PAPI to be on any real value. Straighten me out guys! Thanks.
re: What am I missing?
I certainly agree that not only below 200ft, but by the time you pass MDA/DA/DH you should be visual and looking for the runway (with approach lights in view) or looking at the runway itself, ideally the actual touchdown zone. If the touchdown zone is in view, the PAPI will be too, since it is longitudinally abeam the touchdown zone. The PAPI should be good reference while visual in extremely windy and limited visibility conditions. It was put there for a reason and designed for this very purpose.
We assume that trained and qualified pilots, ATPs especially, should be able to visually assess the aircraft's position for landing and complete the visual segment to a safe touchdown - or go around. Something in this particular approach event defeated that and the airplane touched down short of the runway.
Without placing blame on anyone, what is it in our system that we see such events? Was the airplane suitably stabilized on the approach? Was there sufficient visibility to conduct the localizer only approach and landing? Was something missing or optically illusional in the visual cues? Is more training and proficiency needed to actually fly the visual segment, and make the correct decision about landing or go-around?
If we cannot count on pilots to skillfully perform the visual segment - visually - then the safety basis for all but Cat III instrument approaches is faulty.
We assume that trained and qualified pilots, ATPs especially, should be able to visually assess the aircraft's position for landing and complete the visual segment to a safe touchdown - or go around. Something in this particular approach event defeated that and the airplane touched down short of the runway.
Without placing blame on anyone, what is it in our system that we see such events? Was the airplane suitably stabilized on the approach? Was there sufficient visibility to conduct the localizer only approach and landing? Was something missing or optically illusional in the visual cues? Is more training and proficiency needed to actually fly the visual segment, and make the correct decision about landing or go-around?
If we cannot count on pilots to skillfully perform the visual segment - visually - then the safety basis for all but Cat III instrument approaches is faulty.
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Got cleared for a visual approach in really bright sunlight and flew a curved constant aspect approach rolling out onto final at about 800' AGL with the aiming point in the right place and stable, on speed, very pleased with myself, and got a very agitated pilot in the other seat tell me I was high when the four whites became just about visible at about 400' (you couldn't see the lights before that because of the sun). They fairly quickly went one white, three reds, two reds two whites, one white three reds and then we landed in the right place at the right speed. I often fly with a logger and we analysed the points afterwards and I had flown a reasonably accurate 3.5 degree glide path with no change in power setting at all from 3500' until I closed the throttles at about 40'. My aeroplane will comfortably fly an approach up to about a 4 degree glide and there are procedures which allow an approach path up to 4.5 degrees. In my opinion, picking up and adjusting to the lights at approximately 400 feet would have destabilised the approach or at least risked that but flying a clearly stable visual approach (exactly as if there were no lights at all or they were out of service) was fine. To answer the original posters question, surely you can't simply fly three whites and a red or three reds and a white to fly a three degree approach in an aircraft thats got a different eye height to what the lights are set for. If you fly 2R2W you are on the path the lights are set for and if the eye height is different you will touch down deep or short (probably deep as they should be set for the largest type). If you fly a different combination, youre on a different path. Isnt it as simple as that?
surely you can't simply fly three whites and a red or three reds and a white to fly a three degree approach in an aircraft thats got a different eye height to what the lights are set for.
Just fly 2w/2r. If you are in a long-body, the PAPI MEHT will/should be set further in so you don't tocuhdown short. If you're in a little tiddler (737, 320) then you will touch down longer than normal (if you haven't changed the aim point to the 300m markers) but who cares, the runway will be more than long enough, unless Aeroscat is doing WIP on the far end!
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Yes. That's why I said "surely you can't"......
And the point is if you can't see the lights you fly an approach based on experience. If you see PAPIs at 400 feet that don't agree, who cares! If the approach is right, carry on. I wouldn't change an approach path on breakout at 200 or 100 based on the PAPIs following a perfectly stable approach. I'd keep the descent rate the same, the aiming point steady in the windscreen, and mentally revise what I'm going to do if I baulk. Sod the PAPIs! Irrelevant at that point.
And the point is if you can't see the lights you fly an approach based on experience. If you see PAPIs at 400 feet that don't agree, who cares! If the approach is right, carry on. I wouldn't change an approach path on breakout at 200 or 100 based on the PAPIs following a perfectly stable approach. I'd keep the descent rate the same, the aiming point steady in the windscreen, and mentally revise what I'm going to do if I baulk. Sod the PAPIs! Irrelevant at that point.
Last edited by GlenQuagmire; 27th Jun 2015 at 11:21. Reason: Forgot what I was going to say. Age getting to me.
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Fairly unusual to get a black hole illusion when flying a visual approach in extremely bright sunshine which is what caused the PAPIs to be invisible..
Just to be clear, what do you do when you break out at 200 feet from an ILS and see three reds or three whites? Keep the stable approach going or fanny about with pitch and power to get 2 reds and 2 whites? PAPIs becoming observable late on a visual approach is the same. Do you divert if they are unservicable?
Just to be clear, what do you do when you break out at 200 feet from an ILS and see three reds or three whites? Keep the stable approach going or fanny about with pitch and power to get 2 reds and 2 whites? PAPIs becoming observable late on a visual approach is the same. Do you divert if they are unservicable?
Originally Posted by GlenQuagmire
If you see PAPIs at 400 feet that don't agree, who cares!
Originally Posted by GlenQuagmire
I wouldn't change an approach path on breakout at 200 or 100 based on the PAPIs following a perfectly stable approach.
Originally Posted by GlenQuagmire
what do you do when you break out at 200 feet from an ILS and see three reds or three whites? Keep the stable approach going or fanny about with pitch and power to get 2 reds and 2 whites? PAPIs becoming observable late on a visual approach is the same. Do you divert if they are unsurviceable?
As for diverting, here, we are permitted to operate without slope guidance for only 7 days. And in that 7 days, you must be qualified for no-slope landings.
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Your mindset of someone needing to be a hero to fly a visual approach is exactly what's wrong with today's fly by numbers magenta line environment.
It's not heroic of a pilot to make a visual approach. It's utterly dismal if they can't! Are you telling me that you can't accurately land your aircraft visually without glide slope information? Astonishing...
It's not heroic of a pilot to make a visual approach. It's utterly dismal if they can't! Are you telling me that you can't accurately land your aircraft visually without glide slope information? Astonishing...