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-   -   SWA 737 overrun at BUR - Dec 6 2018 (https://www.pprune.org/accidents-close-calls/616111-swa-737-overrun-bur-dec-6-2018-a.html)

vilas 12th Dec 2018 03:33


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...
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.

punkalouver 12th Dec 2018 03:40


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.

Different type of operation, but when operating turboprops on short, snow covered remote airstrips years ago, we would almost always intentionally go below the Papi's on short final. No doing so was the higher risk decision.

Sailvi767 12th Dec 2018 11:42


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 ?

i think the question is did they have the performance data. Was it updated with the large report of very heavy rain?

Check Airman 12th Dec 2018 12:29


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).

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.

aterpster 12th Dec 2018 12:47


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.

At LGA if I did that in the 1011, I'd be risking leaving the main gear with the end of the pier.

West Coast 12th Dec 2018 15:10

That's where airmenship comes into play. Long body/heavy perhaps not, narrow body perhaps yes.

meleagertoo 12th Dec 2018 15:23


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 ?

Alive and still in posession of licence and job.

Check Airman 12th Dec 2018 16:02


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.

I've seen Air Canada go to LGA with a 767-300. Not an assignment I'd be hurrying to take. In a narrowbody though, it's quite safe.

172_driver 12th Dec 2018 16:06


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.
I am aware of the realities we face in day to day operation, I am assuming we have a valid landing performance. With good visual references and decent knowledge where my under carriage is, I could easily buy myself a couple of hundred feet. What if the undershoot is a displaced threshold? As I said, not everyone's cup of tea.

PEI_3721 12th Dec 2018 18:04

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 … .

FlightDetent 12th Dec 2018 18:17

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.

Airbubba 12th Dec 2018 18:54


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.

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.

Check Airman 12th Dec 2018 19:37


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.

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.

JPJP 12th Dec 2018 21:01


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.

True. Although, more commonly the mains are touching at or just before the 1000 foot markers. Rather that being in mid-flair there.

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.



The Ancient Geek 12th Dec 2018 22:42

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.

Fursty Ferret 12th Dec 2018 22:47


. 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.
Absolutely spot on.

Vessbot 12th Dec 2018 23:02


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.

Are you calling the 1000 foot markers the piano keys?

aterpster 13th Dec 2018 00:25


Originally Posted by West Coast (Post 10334094)
That's where airmenship comes into play. Long body/heavy perhaps not, narrow body perhaps yes.

Before I flew the 1011 into LGA I briefly flew the DC9-10 into there and many years flew the 727 into there. I wouldn't have considered a duck-under with the 727. The only difference the company touchdown zone for the narrow bodies was 500 feet closer to the threshold then with the 1011.

Capn Bloggs 13th Dec 2018 03:32


Originally Posted by Ancient Geek
All modern aids such as ILS and PAPI are calibrated for the piano keys Fixed Distance markings so the actual landing distance available is less than the runway length which can become an issue for shorter runways in poor weather conditions.

Apart from the mixup with Piano Keys and the Fixed Distance markings at 1000ft in, this statement isn't right. The LDR takes into account an air-run distance from 50ft to touchdown. In my aeroplane the air-run distance is 455m, almost 1500ft. "Duck under" and use part of that 455m to roll along on if you wish, but the LDR figures assume you will take 455m/1500ft to get the wheels on the ground.


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.

I think those effects are overstated. But more importantly, flying three reds allow you to plant it with almost no flare. In my experience, it is the type of flare that is the thing that most-affects the touchdown point. Not that I am suggesting you routinely fly three reds! ;)

vilas 13th Dec 2018 04:08

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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