PPRuNe Forums - SWA 737 overrun at BUR

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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)

I bolded the most relevant parts pertaining to NTSB 830 reporting requirements. Major repairs are defined in CFR 14 part 43 and require a properly filled out and signed form 337. The completion of this form constitutes the approval of the repair by an appropriately qualified and authorized inspector and becomes part of the aircraft maintenance record.

Quote:

Originally Posted by NTSB 830.2 (definitions)

[edited for brevity]

Aircraft accident means an occurrence associated with the operation of an aircraft which takes place between the time any person boards the aircraft with the intention of flight and all such persons have disembarked, and in which any person suffers death or serious injury, or in which the aircraft receives substantial damage. For purposes of this part, the definition of “aircraft accident” includes “unmanned aircraft accident,” as defined herein.

Substantial damage means damage or failure which adversely affects the structural strength, performance, or flight characteristics of the aircraft, and which would normally require major repair or replacement of the affected component. Engine failure or damage limited to an engine if only one engine fails or is damaged, bent fairings or cowling, dented skin, small punctured holes in the skin or fabric, ground damage to rotor or propeller blades, and damage to landing gear, wheels, tires, flaps, engine accessories, brakes, or wingtips are not considered “substantial damage” for the purpose of this part. Substantial damage means damage or failure which adversely affects the structural strength, performance, or flight characteristics of the aircraft, and which would normally require major repair or replacement of the affected component. Engine failure or damage limited to an engine if only one engine fails or is damaged, bent fairings or cowling, dented skin, small punctured holes in the skin or fabric, ground damage to rotor or propeller blades, and damage to landing gear, wheels, tires, flaps, engine accessories, brakes, or wingtips are not considered “substantial damage” for the purpose of this part.

edmundronald

That is a comforting sentiment to entertain, but in the real world, a pilot who diverts to an alternate in order to avoid a landing that the data supports will most certainly get a phone call from his base chief pilot asking him to explain himself. This implicit pressure certainly can cloud judgement. Unfortunately, the aviation industry employs "binary decision making" (i.e. there is no spectrum of safety, an operation is either safe or unsafe, no grey areas are acknowledged).

My operator uses LD*SAFO +500'. I'm very happy to report that we're unlikely to get a phone call for making a prudent decision in marginal Wx.
Either the environmentals were incorrectly reported in this case, or the jet didn't land in the right place. I know Burbank is closer to many peoples destination than LAX, but this was taking things a little too far...
As an aside, I watched Mike Pences' 737 steer round the EMAS in LGA one rainy night. Luckily the six lane Grand Central Parkway was there to absorb his overrun...Some wit photoshopped the Vice Presidential Seal on a satellite picture of the EMAS....

Perhaps at SWA, but not at most airlines on that runway with the weather at the time.

NTSB Accident Docket opened: NTSB Docket - Docket Management System

Tower reported wind with the landing clearance directly from the tail, 9 kts, advisory call later with 10 kt tailwind, duly noted as a maximum by the pilots on the CVR.
Approx. 750 RA crew verbalizes 20 knots tailwind from the FMC, but then mere 4 seconds later the tower advises 270/11.
(*)
No further wind observations recorded on the tape.
GS faster than IAS at touchdown by 23 knots, ouch.
Touchdown at Vref 126, around 2500 ft beyond the threshold.
Deceleration diminished to half the previously recorded rate for the last 5 seconds before entering the EMAS.

(*) in detail here what followed:

Quote:

Originally Posted by CVR

0901:36.2 BUR wind two seven zero at one one.
0901:41.3 HOT-2 #.
0901:43.2 HOT-2 er there's five hundred.
0901:44.8 HOT-1 roger.
0901:48.9 HOT-1 we need some kind of lights. I got some lights.
0901:51.6 HOT-2 alright we got eleven knots. you want to call it good?
0901:54.5 HOT-1 yeah.

This, even from a cushy chair, is still somewhat an eye-watering read. If CRM classes on confirmation bias had an exercise for the students to write a script from a hypothetical accident, this would be exactly it. Check the timings, one can almost hear the skipper's brain working the human error. Then the sentence in brown just sealed it airtight, for the grace of God.

Quote:

Originally Posted by 737er (Post 10330765)

Im just trying to keep it real here regarding the specific issue of did they think they had an 11 knot tailwind component and just landed anyway. To that I’d say it’s monumentally and fantastically implausible.

It looks like they acknowledged the 11 knot tailwind and indeed landed anyway.

The Aircraft Performance Study in the Accident Docket has this analysis:

Quote:

Reported vs. actual wind conditions

The maximum tailwind allowed by the SWA AOM is 10 kt. The tailwind component corresponding to the wind report provided by the ATC tower at 09:02 (wind from 270° (magnetic) at 11 knots) is 10.8 kt., i.e., higher than the limit. However, the Captain stated in his interview that he and the First Officer “acknowledged this call and agreed that the tailwind component was 9-10 kt. and it was within limits.” The error in the crew’s estimate of the tailwind component is admittedly small (about 1 kt.); consequently, it is possible that if the winds reported by the tower had been more consistent with the winds recorded by the ASOS (and computed using the FDR data), which were 3 to 5 kt. higher than those reported by the tower, the crew might have recognized that the AOM tailwind limit was exceeded and abandoned the approach.

And, it wasn't just the one knot over the AOM tailwind limit that caused the plane to overrun the runway according to the Aircraft Performance Study:

Quote:

The higher than expected tailwind, the longer than normal touchdown point, and to a lesser degree, the faster than nominal approach speed all contributed to the overrun. However, of the three, the long touchdown is the most significant contributor. The airplane could have stopped on the runway with the high approach speed and tailwind even if the touchdown had been 312 ft. longer than the nominal 1,500 ft. from the threshold; however, with the actual touchdown point of 2,504 ft. from the threshold, either the tailwind or faster approach speed by themselves would have prevented a stop on the runway. Per the SWA AOM, once the airplane overflew the nominal 1,500 ft. touchdown point, the PWB landing distance calculations became “invalid” and “a go-around [was] the better option.”

They did discuss the threats in the briefing.

Quote:

0824:52.9 HOT-2 yeah it's wet with a tailwind...and # short runway.

0824:58.3 HOT-1 awesome.

0825:00.0 HOT-2 yeah that's great. what could possibly go wrong.

Quote:

Originally Posted by Airbubba (Post 10988952)

They did discuss the threats in the briefing.

Now I really start wondering how the "awesome" word was pronounced.
I tend to imagine it with a sarcastic touch, but what if the pilot behind HOT-1 was actually excited about this challlenge?
The pilot behind HOT-2 was far more afraid, yet didn't speak up for busting the OM limit and calling for a go-around.

Contrary opinion here. The HOT2's indistinctive relay of information and downplaying tone greased the stairs.

Clear, unbiased and precise delivery of support facts is the true responsibility of the PM and that has completely failed here. Although we do not see the whole story, why he communicated in such an inadequate manner.

Tangent question: If there was a SIM scenario where tailwind would gradually increase from 7 to 20 knots (assuming limit at 10) below say 400 feet once visual after breaking the cloud, and the PM failed to speak up that the landing must be discontinued,... is it a fail-and-retake situation where you work? Probably it should be, it is a two-pilot operation after all, yet my bet is there is no such general training practice. Certainly have not experienced one like that.

Regardless of the above, the crew was illegal to start lt the approach with regards to LDA under the reported wind conditions. No lessons learned from the previous overrun. The only topic left to discuss is if they did, what will prevent me doing the same as well.

1) Clarify to oneself the difference between the so-called and useless touchdown zone definition (shortest of 900 m or 1/3 runway) and the acceptable touchdown point from the stopping performance viewpoint: THR plus 400 m +/- 200 or 1200 ft +/- 600.

Going beyond the target of 1500 ft / 500 m starts to remove the first protective coat and losing three of them will put the naked truth on the front page. So, train your mind thoroughly to execute a G/A when landing deep. Let there be no doubt the subconscious WILL play your rational self very dirty, same as it did to the skipper here. There will be zero defences not do the stupid thing. Raw sensory information that will trigger an automated escape drill is the
only hope for cases where the PM is gone missing. If you happened to step over any lines in the previous moments no matter how thin and formal, do not expect the F/O to speak as the plot thickens. It's the human nature to stay put and be a good boiled frog.

In pilot speak: No landings beyond the last distance markings! Be acutely aware that PAPIs must be disregarded as a general rule because many of them mark for an aiming point that is already on the far edge of where the touchdown is permissible.

2)... passing on to the next contributor..

YouTube: Southwest Airlines 737 Runway Overrun at Burbank

I notice in the video at 1:10, there is a flash on the left side, which might have been a compressor stall. Is that to be expected if you apply max reverse when moving slowly?