Loss of engine cover on Southwest Boeing 737-800 prompts FAA investigation

[CargoOne]

https://aviation-safety.net/wikibase/386398

[slfool]

Video here: twitter.com/SweeneyABC/status/1777018698345120211


https://twitter.com/SweeneyABC/status/1777018698345120211

[BFSGrad]

Not often that you hear a flight crew say the 12,000 ft runway with the 16 kt headwind isn’t long enough.

[waito]

The Latch Mechanism again?? What is the status of the redesign? I lost track of it.

[Big Pistons Forever]

Seems appropriate for this airline, the left cowl went South and the right cowl went West.

At least this one is going to be hard to blame on Boeing, although I am sure the media morons will try 🙄

[waito]

The video most probably shows the landing back into DEN.
The Outboard cowling ENG #2 detached sometime before, its remainings were tangling in the wind in the video.
Avherald states that flaps were damaged
Short after touchdown the inboard cowling jumped open too and ripped off another few seconds thereafter.

[waito]

Seems appropriate for this airline, the left cowl went South and the right cowl went West.

At least this one is going to be hard to blame on Boeing, although I am sure the media morons will try 🙄

The cowling (nacelle) design is responsibility of the aircraft manufacturer, not the engine company. (Correction: I looked up in the book of an Airbus engineer again, it states the inlet is the task of the airframe manufacturer)

It's not clear if it was a handling/maintenance issue in this case here.

There was a weakness in design on Fan Bladeout Event, detected on the mortal FBO accident some years ago, but this didn't play a role here.

[B2N2]

At least this one is going to be hard to blame on Boeing, although I am sure the media morons will try 🙄

BPF,
How often have you seen this on a Classic?
I rest my case your Honor.

[slfool]

BBC coverage: https://www.bbc.co.uk/news/business-68758088

[ZeBedie]

It looks like they made the damage worse by opening the reversers

[TURIN]

I think this happened over 30 times on the A320 before they changed the design. How often does it happen on the 737?

[Peter H]

https://www.reuters.com/business/aerospace-defense/faa-says-southwest-plane-with-boeing-engine-cowling-fell-off-during-takeoff-2024-04-07/

[Del Prado]

Looks like N8668A

https://www.flightradar24.com/data/aircraft/n8668a

[ATC Watcher]

Nothing really to do with Boeing but very bad timing for this to happen , with a sensational video and Boeing name on the headlines again .
For the average Pax it is parts falling off a Boeing 737 . The PR nightmare for Boeing continues .

[DTA]

This picture is from the UK's Telegraph.

https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/629x393/telg_d167b705bc1ff6cb792b59ac3b16995b7824690c.jpg

[goeasy]

I think this happened over 30 times on the A320 before they changed the design. How often does it happen on the 737?

check ya facts matey….

[WHBM]

Southwest Airlines ... We apologise for the inconvenience of their delay, but place our highest priority on ultimate safety for our customers and employees," a statement said.
To quote a UK transport journalist :

"Statements of safety being 'our highest priority' generally follow an incident which proves that it isn't"

[Jonty]

I think this happened over 30 times on the A320 before they changed the design. How often does it happen on the 737?

Not 30 times, I can name about 3 times it happened.
Thing is, it’s a known issue to the point it prompted a design change from Airbus. Why didn’t Boeing take note and change their design?

[FlexibleResponse]

It looks like they made the damage worse by opening the reversers

Looks like a flapless landing so perhaps they had to use the reversers to stop?

[procede]

They landed on the longest runway in North America, so I really do not see why they needed the reversers...

I can understand them not wanting to use the slats, but why would the flaps would not work?

[waito]

Yes, it was a Flaps Up Landing.
I wonder what the Groundspeed was - especially in Denver!! Anybody to retrieve Vref? What was the winds and temperatures at that time?

[ZeBedie]

Fair point Flex

[Jump Complete]

Yes, it was a Flaps Up Landing.
I wonder what the Groundspeed was - especially in Denver!! Anybody to retrieve Vref? What was the winds and temperatures at that time?

Just looked at the QRH performance, for a 65000KG (143000lbs) landing, trailing edge flaps up and no reversers, Max Manual brakes, I came up with a distance of just over 5000’, roughly half the landing distance available.
VREF 40 at 65T is around 140kts and the checklist suggests VREF 40+ 40kts for trailing edge flaps up (180kts) or 55kts for all flaps up. So flying plus 5kts gives a rather tasty 200kts approach speed!
(Just figures based on a nearly max weight landing without knowing any details other than looking up Denver and seeing it is 5500’ ish elevation.)
EDIT: Figures are for a 737-800, 15*, at home base which is 680’ elevation. So speeds for Denver will be even higher, probably!
My figures for All Flaps up landing, Max manual braking come to just over 6000’.

[FullWings]

Based on the approach speed alone I would think you are looking at a serious amount of runway required. There was a headwind but ISA+10/15 at 5500AMSL is going to add all that back in plus a bit. To be on the safe side you’d plan on losing a reverser as you don’t know with the cowl damage if it will deploy.

Would be surprised if brakes on was less than 200kts groundspeed. Long time since I flew the 737 but that’s going to need a lot of the runway assuming the brakes can take that level of input and still slow you down...

[Ikijibiki]

It looks like they made the damage worse by opening the reversers

Could this be related to the comment by BFSGrad (https://www.pprune.org/members/443704-bfsgrad) about the wind and runway length? Perhaps the pilot had to use the reversers.

[Ikijibiki]

They landed on the longest runway in North America, so I really do not see why they needed the reversers...

I can understand them not wanting to use the slats, but why would the flaps would not work?
Well, if the cowling hit the flaps, maybe they didn't or could use them to land, came in hot and still needed reversers? I don't see the slats deployed in the video of the landing from inside the plane.

[waito]

VREF 40+ 40kts for trailing edge flaps up (180kts) or 55kts for all flaps up. So flying plus 5kts gives a rather tasty 200kts approach speed!


Looked up in a very old FM. Vref 40+55 is correct.
With a mass range of 110-170lbs we then get 177-208KN +5 KN wind we can expect the landing was at 182-213KN IAS
Assumed Wind - Actual Wind still unknown?

What is the Altitude based Ground Speed derived from 182-213KN?

Flightaware shows a Speed of ~210KN, and before touchdown one 184KN mark. I dont know what the speed value means on Flightaware.

Edit:
OK, FR24 showed Groundspeed of 211KN the seconds before touchdown, That is something!!!
Tyre Limit is 190KN?

[Peter Fanelli]

Apparently the aircraft concerned identifies as an A320.

[A0283]

Reported to be N8668A (reg not visible on videos) On takeoff right hand eng#2 right hand aft cowl door came loose first, opened and flapping around … pilots only know after CCW and pax report…pilots think inner flap hit … return for overweight and no flaps landing, fuel 22.9 with 6 crew and 135+2 pax … change from rwy 25 to 26 then 34L …on landing left hand cowl visibly opened too… both doors flapping around and shredding, only small pieces remain…

[xetroV]

Apparently they made a flaps-up landing, believing the LE flaps were damaged.

Video and ATC:
https://youtu.be/GBQkk4RcidA?si=lt7Z1ERo37ZVGU1J

[WillowRun 6-3]

No surprise that as SLF/attorney I'm keeping a big whole runway length out of the pilots talking about flying here. But I will momentarily divert the flying talk to note that at least one main media outlet has not piled onto the ongoing Boeing crisis in reporting on this incident. This morning on CNBC Squawk on the Street the reporting was very factual; incident aircraft manufactured in 2015 and not a MAX, FAA investigating, just the facts, sir or madam.

[FullWings]

Having had a think about it, this is quite a nasty problem to be handed. Enough damage to require a very non-standard landing, possibly > MLW, plus time pressure as the cowls are coming apart and who knows what the next loose bit is going to hit (it’s already done for the flaps and slats), which restricts the options to a land ASAP.

Some of the things that would be going through my mind are: high DA and with the resultant GS, that’s 1,100fpm to stay on the glide slope, so a flare is definitely required to avoid a crash, but at the same time a float will use a lot of runway. Which runway? The long one or the into-wind one? Will the brakes take it? They are certified to some fairly extreme requirements but does a flapless landing at high altitude and high weight fall within them? Don’t want to get brake fade at 100kts when the reversers are starting to lose their effectiveness, so maybe a lower brake setting and let the reverse take more of a share of the energy removal? Will they catch fire soon afterwards or can we limit that? Lots of stuff to think about in a very short time...

[WillowRun 6-3]

Having had a think about it, this is quite a nasty problem to be handed. Enough damage to require a very non-standard landing, possibly > MLW, plus time pressure as the cowls are coming apart and who knows what the next loose bit is going to hit (it’s already done for the flaps and slats), which restricts the options to a land ASAP.

Some of the things that would be going through my mind are: high DA and with the resultant GS, that’s 1,100fpm to stay on the glide slope, so a flare is definitely required to avoid a crash, but at the same time a float will use a lot of runway. Which runway? The long one or the into-wind one? Will the brakes take it? They are certified to some fairly extreme requirements but does a flapless landing at high altitude and high weight fall within them? Don’t want to get brake fade at 100kts when the reversers are starting to lose their effectiveness, so maybe a lower brake setting and let the reverse take more of a share of the energy removal? Will they catch fire soon afterwards or can we limit that? Lots of stuff to think about in a very short time...

Given the above - and pending more definitive information from the incident investigation including especially the pilots - this incident appears destined to join the current list of examples of why single-pilot cockpits, as well as autonomous aircraft operations, would be very ill-advised at the present time and for a long time to come. Among the best examples has been the Delta flight which dumped fuel as part of an emergency return to Los Angeles after encountering some difficulties (Flight 89 Jan. 14, 2020 - subject of much discussion on the forum). Never have I seen even a bald-faced assertion that even projected future algorithms could have successfully operated the emergency return, approach and landing.

Okay, here's another example. Write the algorithm which solves for all the variables and decisions noted by FullWings. I would say, "I'll wait" but I think I'd be waiting a long, long time.

[waito]

Okay, here's another example. Write the algorithm which solves for all the variables and decisions noted by FullWings. I would say, "I'll wait" but I think I'd be waiting a long, long time.
Very good Question! Please Open another Thread to discuss this, and I mean it, because it should be quite interesting. I will try to bring some insight into algorithms vs. AI.

​​​​

[waito]

possibly > MLW
time pressure
high DA
1,100fpm influence on flare and float
high altitude
do brakes take it?

Great list of difficulties!
And this really higher than usual speed squeezes the timing. How does it affect the pitch? probably not that much cause you are relatively same percentage above minimum speed?
How high do you flare?
Will you go below G/S to save some distance on short runways? (not a factor here,i suppose)

[BlankBox]

To quote a UK transport journalist :

"Statements of safety being 'our highest priority' generally follow an incident which proves that it isn't"

Were OK Jack...trust us...:ok:

[MechEngr]

It did not appear to have hit the flaps - the outboard cover was still attached after takeoff and was entirely above the wing and the inboard cover spent its time on the loose over the wing as well. The outboard cover appears to have banged up the top of the nearby slat, but the dents on top aren't as bad as some I've seen from hail damage.

I'd go for excessive caution, but given the entirely unknown situation and being unable to observe beneath the wing, with the option of the long runway they had, it was a reasonable choice to take it.

Most likely the tires are heading for a retread and the brakes will need a look; both a small price vs the potential cost of damage to the horizontal stab if a cover let loose at a higher AoA typical during landing.

[Junkflyer]

They landed on the longest runway in North America, so I really do not see why they needed the reversers...

I can understand them not wanting to use the slats, but why would the flaps would not work?

Flaps and slats work off the same lever. Can't speak for the 737, but typically slats are first or in conjunction with some flaps.

[dixi188]

A question re. Brake energy and V1.
What is the max V1 speed that this 737 could have at max weight?
The brakes are certified to work for a Max weight rejected take off at V1 with Max braking. I suspect the max V1 will be around 170 kts. So this aircraft landed at a speed around 200 kts., at less than max weight, with over 12000ft of runway to stop in. I doubt the brake temps were over limits.
Also I don't think the altitude will affect the IAS but the TAS and ground speed will be higher.
I've been out of flying for over 10 years so maybe I've forgotten something.

[Seat4A]

https://twitter.com/bvrtender/status/1776986468524708334?ref_src=twsrc%5Etfw%7Ctwcamp%5Etweetembe d%7Ctwterm%5E1776986468524708334%7Ctwgr%5Ed03a49027bd7d4d521 ab9bc036ddab8c18ac5c8d%7Ctwcon%5Es1_&ref_url=https%3A%2F%2Fviewfromthewing.com%2Fpassengers-witness-engine-cover-peel-away-on-southwest-boeing-737-forcing-emergency-return-to-denver%2F

[waito]

The time Touchdown to a low speed in the video could be in the 50s region. Especially checking ~20s after touch, does that look like just the regular speed at touchdown? Crazy!

A question re. Brake energy and V1.
What is the max V1 speed that this 737 could have at max weight?

The -800 highest V1 in the table is 162kts and up to +1+1kts for rwy slope and wind adjustment
Of course thatt's not ground speed, but it doesn't matter re your question


Also I don't think the altitude will affect the IAS but the TAS and ground speed will be higher.

correct, plus ISA Temp deviation IIRC

[TURIN]

Not 30 times, I can name about 3 times it happened.
Thing is, it’s a known issue to the point it prompted a design change from Airbus. Why didn’t Boeing take note and change their design?
A brief search that took about 30 seconds revealed 8 cowl losses on A320 series.
I'm pretty sure that after the very well publicised BA incident of double cowl loss there was an AD issued that stated something along the lines if about 30 previous occurrences.

[Last200ft]

Definitely not an easy one, well done by the crew. Just a thought re flap up landing… In theory, even if the slats are damaged, there should still be some sort of asymmetry protection. Would it be worth trying in this kind of scenario? Technically if something goes wrong you can bring them back. Or maybe the system design would stop the slats and let you use the flaps at least? Again, those are just thoughts for myself, kudos to the crew and ATC

[waito]

A brief search that took about 30 seconds revealed 8 cowl losses on A320 series.
I'm pretty sure that after the very well publicised BA incident of double cowl loss there was an AD issued that stated something along the lines if about 30 previous occurrences.

Yes, I remember quite some events. And the assembly had to be changed more than once when incidents continued to happen. IIRC
(Edit: I am still talking of the Airbus cowling door issues)

[TURIN]

check ya facts matey….
https://safetyfirst.airbus.com/preventing-fan-cowl-door-loss/
Since the publication of the original issue of this article there have been 12 further cowl loss incidents.
I don't know how many occurred prior (pre 2012).

Edit to add...

In July 2015 the U.K. AAIB published an investigation report into a fan cowl door loss accident involving an Airbus A319. Prior to this May 2013 accident , there were a total of 34 previous occurrences of fan cowl door loss on Airbus A320-family aircraft, including 21 events for aircraft fitted with IAE V2500 engines and 13 events for aircraft fitted with CFM-56 engines. Following the A319 accident, three further instances of fan cowl door losses occurred, bringing the total number of occurrences to 38.
From... https://fodprevention.com/airbus-a320-family-of-aircraft-engine-fan-cowl-door-loss-incidents-timelines/

[tdracer]

Yes, I remember quite some events. And the assembly had to be changed more than once when incidents continued to happen. IIRC
I've seen conflicting information on if this was a 737-800NG or a MAX-8 (although based on the reported delivery date it would have had to have an NG). Assuming I'm correct that it was an NG, there are something like 5,000 of them flying around with the same cowl design, racking up well north of a million engine hours per month.
Given this is the first reported cowling 737 cowling event I can recall, it certainly doesn't sound like the kind of generic problem they had on the A320.
But don't let that stop the dedicated Boeing bashers...

[waito]

I've seen conflicting information on if this was a 737-800NG or a MAX-8 (although based on the reported delivery date it would have had to have an NG). Assuming I'm correct that it was an NG, there are something like 5,000 of them flying around with the same cowl design, racking up well north of a million engine hours per month.
Given this is the first reported cowling 737 cowling event I can recall, it certainly doesn't sound like the kind of generic problem they had on the A320.
But don't let that stop the dedicated Boeing bashers...
Yes, I agree.
To be clear, I was referring to the A320 family with its many cowling door events. And so we should stop now and focus on this incident with the 738.

And it's unlikely that this is a design or durability issue. There are older 738 with no nacelle issue.And what TD said.

[DaveReidUK]

It looks like they made the damage worse by opening the reversers

Well we'll never know what the consequence of not opening the reversers might have been.

[TURIN]

I've seen conflicting information on if this was a 737-800NG or a MAX-8 (although based on the reported delivery date it would have had to have an NG). Assuming I'm correct that it was an NG, there are something like 5,000 of them flying around with the same cowl design, racking up well north of a million engine hours per month.
Given this is the first reported cowling 737 cowling event I can recall, it certainly doesn't sound like the kind of generic problem they had on the A320.
But don't let that stop the dedicated Boeing bashers...

2022, Alaska Airlines.
https://simpleflying.com/alaska-airlines-boeing-737-loses-engine-cowling/

[langleybaston]

To quote a UK transport journalist :

"Statements of safety being 'our highest priority' generally follow an incident which proves that it isn't"

Our first priority is profit
Our second priority is passing the buck up, down, sideways if anything goes wrong
Our third priority is lining up our next career move

[pattern_is_full]

Apparently the aircraft concerned identifies as an A320.

Really? Where?

SWA does not operate any aircraft type except 737 variants (to maintain system-wide crew compatability).

https://en.wikipedia.org/wiki/Southwest_Airlines_fleet

https://registry.faa.gov/AircraftInquiry/Search/NNumberResult?nNumberTxt=8668A

[Capn Bloggs]

Apparently they made a flaps-up landing, believing the LE flaps were damaged.
Why didn't one of them go to have a look?

Really? Where?
He's pulling ya leg.

[22/04]

So do these cowls latch to one another? And would decreasing airflow as the speed reduces then cause the second one to open? And how evident would unlocking be on a walk round?

[waito]

Our first priority is profit
Our second priority is passing the buck up, down, sideways if anything goes wrong
Our third priority is lining up our next career move
Well, safety IS the highest:
https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/1080x1527/safety_is_our_highest_concern_209bbe507d1f03f040d928f5ece271 6ba9dde762.jpg

[framer]

If they had planned on arriving in Houston with around 3T of fuel ( just a guess) then they would have been pretty close to MLW when they made the approach back into Denver. My book gives me an approach speed of 201kts and a factored landing distance of almost exactly 12000ft using A/B 3 and one reverser.
Like others have said there are considerations around wheel fires and brake fade that would definitely drive me to the longest runway available in that circumstance. It would be a delicate balance of ensuring stopping in the distance available and not cooking the brakes to the point they can’t absorb any more energy.
Well done to that crew.

[TURIN]

Really? Where?

SWA does not operate any aircraft type except 737 variants (to maintain system-wide crew compatability).

https://en.wikipedia.org/wiki/Southwest_Airlines_fleet

https://registry.faa.gov/AircraftInquiry/Search/NNumberResult?nNumberTxt=8668A
The A320 family have had multiple events like this, well over 30. He/she was joking.

[framer]

And how evident would unlocking be on a walk round?
You have to get down low to check. I have to rest my weight on one hand and think of it as a kind of yoga stretching exercise :)

[deeceethree]

To quote a UK transport journalist :

"Statements of safety being 'our highest priority' generally follow an incident which proves that it isn't"

Well done that journalist! 👏🏻👏🏻👏🏻

The puerile use of the phrase "our top (or highest) priority" is one of my pet hates. It is used by people within organisations who have absolutely nothing useful, meaningful or sincere to say. Unfortunately, it's use has become so common that it is clear the population of oxygen-stealing morons is rapidly increasing, like an infestation of coakroaches. 🙄

[waito]

We can see the state of the outboard door after many minutes of flight. For me it looks complete, which points to "just" an unlatched status (or broken latch mechanism). Not a crack, not a structural problem in the door itself.

If correct, this makes a Boeing/CFM design or production error extremely unlikley.

Another note: the LE device, slat next to the engine seem to show sort of puncture. Reason enough to avoid using flaps. Possible assymetry in slats is quite uncomfortable. As would TE setting without LE, but I think this is prevented.

[waito]

Reported to be N8668A (reg not visible on videos) On takeoff right hand eng#2 right hand aft cowl door came loose first, opened and flapping around … pilots only know after CCW and pax report…pilots think inner flap hit … return for overweight and no flaps landing, fuel 22.9 with 6 crew and 135+2 pax … change from rwy 25 to 26 then 34L …on landing left hand cowl visibly opened too… both doors flapping around and shredding, only small pieces remain…
What source, is it trustworty? Especially the fuel figure, we could then estimate the landing weight.

[tdracer]

Flaps and slats work off the same lever. Can't speak for the 737, but typically slats are first or in conjunction with some flaps.
If memory serves, the LE device deploys as soon as you go flaps 1 - so there is not a flap setting that wouldn't have deployed the (potentially damaged) leading edge.
There is probably some technique of pulling circuit breakers or the like to prevent LE deployment, but I doubt that would be in the checklist.

[xetroV]

Another note: the LE device, slat next to the engine seem to show sort of puncture. Reason enough to avoid using flaps. Possible assymetry in slats is quite uncomfortable. As would TE setting without LE, but I think this is prevented.
During the roll-out the engine cover punctured a slat (it appears at 7:50 in the video I posted earlier in post #30 (https://www.pprune.org/11631576-post30.html)); the puncture did not seem to be present during flight. Which makes me wonder whether the crew visually inspected the damaged engine cowling themselves before deciding to do a flaps-up landing. Also note that they told ATC they had "structural damage", which suggests that they believed the damage was more substantial than 'just' a loose engine cowling.

I'm not criticizing their decision-making, by the way; after all they did have a very long runway readily available for an immediate overweight flaps-up landing. And I can totally understand why they wanted to land ASAP, considering the possibility of debris from the engine hitting the wing (or even the horizontal stabilizer).

[waito]

If memory serves, the LE device deploys as soon as you go flaps 1 - so there is not a flap setting that wouldn't have deployed the (potentially damaged) leading edge.
There is probably some technique of pulling circuit breakers or the like to prevent LE deployment, but I doubt that would be in the checklist.
Correct in normal conditions
Flaps 1-5 drives the 8 LE slats in intermediate extended, and 2 LE flaps into full extended pos as soon as lever leaves flaps up setting.

[Junkflyer]

If memory serves, the LE device deploys as soon as you go flaps 1 - so there is not a flap setting that wouldn't have deployed the (potentially damaged) leading edge.
There is probably some technique of pulling circuit breakers or the like to prevent LE deployment, but I doubt that would be in the checklist.

I remember the story of a captain on the 727 who used to pull a c/b for L/E devices and put a slight bit of flaps in to increase speed in cruise. As legend goes, one of the other crewmembers came back into the cockpit and noticed the c/b out so pushed it in. The leading edges came out but one tore off or something and sent the aircraft into a roll and the aircraft lost thousands of feet in altitude before recovering.

[waito]

... the puncture did not seem to be present during flight.


Well, look at the picture in post 15. puncture is visible, and it appears to be in flight.

[MartinB738]

Not 30 times, I can name about 3 times it happened.
Thing is, it’s a known issue to the point it prompted a design change from Airbus. Why didn’t Boeing take note and change their design?

What was the design change? I recall talk of a spreader to force the cowls apart if unlatched, and a warning light? Thanks in anticipation.

[slacktide]

I remember the story of a captain on the 727 who used to pull a c/b for L/E devices and put a slight bit of flaps in to increase speed in cruise.

Wow, I bet that was a real Hoot.

[Loose rivets]

It probably went supersonic and caused the right landing gear to be pushed back into the wing structure. The decent was probably the most dramatic for a non fatal accident in the history of aviation.

[TURIN]

What was the design change? I recall talk of a spreader to force the cowls apart if unlatched, and a warning light? Thanks in anticipation.
A key was introduced on the CEO fleets. The key is kept in the flt deck with the landing gear ground locks. To open the cowling the key is inserted under the engine and cannot be removed until the cowlings are latched closed again. The key has a long 'remove before flight' flag attached.
On the NEO fleet there is a spring that pushes the cowlings apart, there is also a mechanical flag that pops out of the side of the cowling if the (no.2?) latch isn't locked and there's also a flt deck ECAM warning if the cowlings are not fully latched.
Maybe it's time Boeing did something similar.

[FullWings]

Definitely not an easy one, well done by the crew. Just a thought re flap up landing… In theory, even if the slats are damaged, there should still be some sort of asymmetry protection. Would it be worth trying in this kind of scenario? Technically if something goes wrong you can bring them back. Or maybe the system design would stop the slats and let you use the flaps at least? Again, those are just thoughts for myself, kudos to the crew and ATC
With a non-normal, once you have got the aeroplane into a configuration which is safe for flying and landing (but maybe unusual) conventional wisdom says stop “troubleshooting” and get on with it. Attempting something novel to make things “better” at that point has a limited upside and a potentially unlimited downside. Especially if you don’t have intimate knowledge of what exactly is wrong...

[Yancey Slide]

I remember the story of a captain on the 727 who used to pull a c/b for L/E devices and put a slight bit of flaps in to increase speed in cruise. As legend goes, one of the other crewmembers came back into the cockpit and noticed the c/b out so pushed it in. The leading edges came out but one tore off or something and sent the aircraft into a roll and the aircraft lost thousands of feet in altitude before recovering.

TWA 841

[OldnGrounded]

TWA 841

It's a helluva story.

Gibson shouted, "We're going over!". Flight 841 dove about 34,000 feet (10,000 m) in just 63 seconds.[3] (https://en.wikipedia.org/wiki/TWA_Flight_841_(1979)#cite_note-AAR-81-08_Final_Report-3): 2  During the course of the dive, the plane rolled through 360 degrees twice and exceeded the Mach (https://en.wikipedia.org/wiki/Mach_number) limit for the 727 airframe (https://en.wikipedia.org/wiki/Airframe).

https://en.wikipedia.org/wiki/TWA_Flight_841_(1979)

https://www.ntsb.gov/investigations/AccidentReports/Reports/AAR8108.pdf

[Sailvi767]

Not 30 times, I can name about 3 times it happened.
Thing is, it’s a known issue to the point it prompted a design change from Airbus. Why didn’t Boeing take note and change their design?

Because the design is fine. You just need to latch it. Southwest Airlines until recently did not require pilot walk arounds relying on rampers to do the preflight. Not sure in this case if a pilot was required to walk around.

[Peter Fanelli]

Really? Where?

SWA does not operate any aircraft type except 737 variants (to maintain system-wide crew compatability).

https://en.wikipedia.org/wiki/Southwest_Airlines_fleet

https://registry.faa.gov/AircraftInquiry/Search/NNumberResult?nNumberTxt=8668A


You must be the life of every party.
It was a sarcastic remark.

[waito]

NTSB stopped investigating this event.
Maintenace haopened the night before, and NTSB is satisfied with declaring it a maintenance issue and the airline addressing it.

See avherald, where I picked this up.

[BFSGrad]

N8668A patched up enough to fly. Currently enroute from DEN to PAE. Since SWA doesn’t serve PAE, assume positioning is for additional maintenance at Boeing.