If the undershoot is flat you can duck under to get extra distance. Not everyone's cup of tea, but if you're close to the margain... |
Originally Posted by vilas
(Post 10333658)
The very fact that you feel that the approch requires something which is not done is a message that you shouldn't be landing there. Short runway, limit tail wind which could easily go over the limit, heavy rain can make the braking action poorer than imagined and control of flight path difficult these are too many variables which can prevent a successful outcome. Not a safe decision to continue the landing.
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Originally Posted by Meester proach
(Post 10333330)
So if the performance data was OK, and you diverted where does that leave you ? What could make a difference is local knowledge - does this runway feel like it actually meets the performance normally or not from past experience ? |
Originally Posted by CHfour
(Post 10333476)
"Not everyone's cup of tea" Really? If you try that one over on my side of the pond you'll find yourself in the Chief Pilot's office and there won't be any "cup of tea" (or any biscuits for that matter).
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Originally Posted by Check Airman
(Post 10333961)
For exercising airmanship? In limiting conditions, many ppl will go 3 red on the PAPI at LGA or DCA for example (where your final approach is over water) to get a few extra feet of runway.
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That's where airmenship comes into play. Long body/heavy perhaps not, narrow body perhaps yes.
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Originally Posted by Meester proach
(Post 10333330)
So if the performance data was OK, and you diverted where does that leave you ? What could make a difference is local knowledge - does this runway feel like it actually meets the performance normally or not from past experience ? |
Originally Posted by aterpster
(Post 10333980)
At LGA if I did that in the 1011, I'd be risking leaving the main gear with the end of the pier.
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The very fact that you feel that the approch requires something which is not done is a message that you shouldn't be landing there. Short runway, limit tail wind which could easily go over the limit, heavy rain can make the braking action poorer than imagined and control of flight path difficult these are too many variables which can prevent a successful outcome. Not a safe decision to continue the landing. |
172, ‘valid landing performance’, no such thing before the landing, only judgement of the unknowns: wet or flooded, what about all the conditions in between. Who measures / reports the conditions; the same with wind, at least +/- 2, so allow +/- 5. There are few absolutes in flying other than the position where you stop; assumption kill, so concentrate on minimising all other variables, speed, touchdown, bakes, etc … . |
There is no short landing technique on a jet this size. Arriving on a decreased angle (3 red) carries higher pitch, more thrust, flatter sink and in general results in a longer touchdown and a higher speed at wheel spin-up. After that, exactly the same sort of people who use the A word to cover gaps in competency or understanding, will immediately claim: see how tight this was? Lucky my skygod decision to go 3 reds, it saved us. Yeah.
Aiming closer to the threshold, steepening the angle in the last stages is more consistent with the intention. Why not, if you know how not to try too hard. Still, reducing geometrical margins on purpose, creating ad-hoc flying techniques, is not the road to a happy retirement. Land it consistently, as much identical as your everyday approach. Consistency brings predictable results. The touchdown is usually decided between 150 and 50 feet above the ground. If a runway below 2000 m requires a different skill-set, then the one you have on the longer runways is not a correct one. (Placement of PAPI at 400 or 450 m beyond the THR, as opposed to 291 m where the G/S geometric intercept is, WILL create a wrong skill set for those who follow PAPI through to the landing). The above is a comment to the discussion here, not the incident itself. We will see what the investigation reveals, however, "no landings beyond TDZ markings" is a sound principle. I am curious to see if it did not work in BUR? One last note: the (lack of) friction over THR markers at the far end, when wet/snowed, is what makes this man uneasy. The last 60 m you might critically need, and as if they did not exist. I suppose everyone had a NW skid during line up once, for no apparent reason. |
Originally Posted by Check Airman
(Post 10333961)
For exercising airmanship? In limiting conditions, many ppl will go 3 red on the PAPI at LGA or DCA for example (where your final approach is over water) to get a few extra feet of runway.
Originally Posted by aterpster
(Post 10333980)
At LGA if I did that in the 1011, I'd be risking leaving the main gear with the end of the pier.
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Originally Posted by Airbubba
(Post 10334268)
I've seen folks who brief that they want to drop a dot low on the glideslope on short final in widebodies 'since the weather is good'. Is this in the book anywhere? I get the impression that this 'technique' was taught in some Air Force communities (possibly the C-141) years ago. |
Originally Posted by Check Airman
(Post 10334300)
Not in any book that I've seen, but when landing on a short, wet runway as described above, most of the people I fly with decide against leaving the first thousand feet of the runway behind.
The expression used was ‘duck under’ (the glide path) on short final. The concept, and the expression were remarkably unpopular with the FAA due to the quite sensible requirement for a stabilsed approach. Ducking under was replaced with the more politically correct term of ‘adjusting the aim point’. Midway, Key West and Burbank are relevant examples. |
This boils down to how much runway should be behind the touchdown point. When I were a lad, many moons ago, there were no piano keys and we were taught to aim for the numbers. The piano keys were introduced to reduce the incidence of landing short of the paved surface, thus "wasting" part of the runway. All modern aids such as ILS and PAPI are calibrated for the piano keys so the actual landing distance available is less than the runway length which can become an issue for shorter runways in poor weather conditions.
Should we aim shorter for the numbers in these cases ? - I will leave that can of worms for others to chew, the risks have not changed. Aiming for a firm contact, avoiding greasers, is probably a better idea getting good weight on the wheels ASAP to improve braking. |
. If a runway below 2000 m requires a different skill-set, than the one you have on the longer runways is not a correct one. |
Originally Posted by The Ancient Geek
(Post 10334412)
This boils down to how much runway should be behind the touchdown point. When I were a lad, many moons ago, there were no piano keys and we were taught to aim for the numbers. The piano keys were introduced to reduce the incidence of landing short of the paved surface, thus "wasting" part of the runway. All modern aids such as ILS and PAPI are calibrated for the piano keys so the actual landing distance available is less than the runway length which can become an issue for shorter runways in poor weather conditions.
Should we aim shorter for the numbers in these cases ? - I will leave that can of worms for others to chew, the risks have not changed. Aiming for a firm contact, avoiding greasers, is probably a better idea getting good weight on the wheels ASAP to improve braking. |
Originally Posted by West Coast
(Post 10334094)
That's where airmenship comes into play. Long body/heavy perhaps not, narrow body perhaps yes.
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Originally Posted by Ancient Geek
All modern aids such as ILS and PAPI are calibrated for the
Originally Posted by Flight Detent
Arriving on a decreased angle (3 red) carries higher pitch, more thrust, flatter sink and in general results in a longer touchdown and a higher speed at wheel spin-up.
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No aircraft manufacturer or Company SOP suggests duck under technique nor does certified landing performance expects a pilot to do that. So there is simply no justification narrow body, wide body, turbo prop all included. If there is a runway which requires that then that type of aircraft should not be operating there. It is not proper to suggest unsafe alternate techniques to increase landing run for the present SWA case. If the touchdown was at proper distance then it will prove that the landing should not have been affected with so many limiting variable environmental and RW lenth factors.
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