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Another Southwest close call

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Another Southwest close call

Old 17th Jun 2024, 16:29
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Originally Posted by EXDAC
The RNAV 17 approach plate I'm looking at has an MDA of 940. Is SWA using a different procedure with a DA? if so, what is that DA and what would be a reasonable descent below DA for a missed approach?
....I'm guessing more than 409'RA
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Old 17th Jun 2024, 17:24
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Originally Posted by Check Airman
US airlines operate a bit differently. Unless the FO is "high mins" (under 100hrs on type), he/she would be expected to handle all 3 of those situations you mentioned. The CA may ask a relatively inexperienced FO if he's comfortable with a particularly challenging approach, but at some point, you'll have to give the FO a chance to do it. The report even states the CA elected to have the FO fly the approach in order to build experience.
I did not mean to insinuate the captain would NEED to fly the approach under those conditions but with a new FO the Captain may have considered those more challenging than your typical IMC approach.
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Old 17th Jun 2024, 17:29
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Originally Posted by Lookleft
I would guess that the Captain is regretting his decision.
Yeah, I'm sure he would like to rewind that one for a do over.
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Old 17th Jun 2024, 18:19
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Originally Posted by EXDAC
The RNAV 17 approach plate I'm looking at has an MDA of 940. Is SWA using a different procedure with a DA? if so, what is that DA and what would be a reasonable descent below DA for a missed approach?
The descent to 400 was not intentional, MDA is irrelevant. It was the bottom of the pullout from the 4000 fpm unintentional dive.
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Old 17th Jun 2024, 18:46
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Originally Posted by Vessbot
The descent to 400 was not intentional, MDA is irrelevant. It was the bottom of the pullout from the 4000 fpm unintentional dive.
I don't understand the point that you and Capn Bloggs are making. If the approach had an MDA and the aircraft descended below MDA without visual contact how was it not below minimums? Unlike a DA the MDA is intended to be a hard floor that is not violated during a missed approach (or is that what you disagree with?)

I'm not saying the crew intentionally descended below minimums, only that they did. From the leaked report it seems it was only the EGPWS that saved them.
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Old 17th Jun 2024, 19:06
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Originally Posted by EXDAC
I don't understand the point that you and Capn Bloggs are making. If the approach had an MDA and the aircraft descended below MDA without visual contact how was it not below minimums? Unlike a DA the MDA is intended to be a hard floor that is not violated during a missed approach (or is that what you disagree with?)

I'm not saying the crew intentionally descended below minimums, only that they did. From the leaked report it seems it was only the EGPWS that saved them.
Your question over whether the airline is authorized lower than published MDA, as if you're looking for a justification on crew's part to descend that low, is what made me interpret your post this way.

Sounds like we agree it was not intentional.

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Old 17th Jun 2024, 19:40
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Originally Posted by EXDAC
I don't understand the point that you and Capn Bloggs are making.
You seem to be stuck.

Read AVHERALD to get a good initial overview - it even shows the RNAV chart 17!

​​​​​They decided and executed a missed approach at ~1000ft AGL. MDA seems to be 800ft AGL. So they did not bust the minimum at that point! I haven't read yet if they had a short climb or not.

Only AFTERWARDS​​​​, the PF inadvertently dived towards the ground. That's not simply a MDA bust, but rather sort of loss of control. With or without visibility conditions. They were low, and had a large sink rate, that's what went wrong
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Old 17th Jun 2024, 19:49
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Originally Posted by Vessbot
Your question over whether the airline is authorized lower than published MDA, as if you're looking for a justification on crew's part to descend that low, is what made me interpret your post this way.
I was attempting to find some meaning in "EXDAC, the 400ft was the descent after the Missed Approach was in progress."

That statement seemed to imply that descending below MDA is ok afer the missed approach has started. Since that's not true I was wondering if a DA was in effect for a special SWA approach procedure. So far, no one has confirmed that such a special procedure was in use.


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Old 17th Jun 2024, 20:15
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Originally Posted by EXDAC
That statement seemed to imply that descending below MDA is ok afer the missed approach has started.
It does not imply that. It implies that after the missed approach started, they lost control and nearly lawn darted into the ocean (repeat of Atlas 3591), before barely pulling out.

Last edited by Vessbot; 17th Jun 2024 at 22:48.
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Old 17th Jun 2024, 20:21
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This is the best I can do for data for this flight. A KML file was exported from ADS-B exchange and imported into GE. The data is low resolution and has other limitations but I see no missed approach climb before the uncontrolled dive. (Please note that the x axis of the elevation profile is along path distance not time.)








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Old 17th Jun 2024, 20:59
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I don't see comments and thoughts on what I am thinking. IF durning the go-around, with the application of TOGA AND if then the F/O pushed down on the elevator AND without any other info relevant to that what makes this any different than the Atlas/Prime 767 accident approaching KIAH? This would be a case of Somatogravic Effect. I understand that the flight instruments displayed the reality as they did on the 767 accident. However I am thinking this may be it and SWA dealt with it as it would if it was reviewed as what it was.
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Old 17th Jun 2024, 21:42
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Originally Posted by EXDAC
I don't understand the point that you and Capn Bloggs are making. If the approach had an MDA and the aircraft descended below MDA without visual contact how was it not below minimums? Unlike a DA the MDA is intended to be a hard floor that is not violated during a missed approach (or is that what you disagree with?)

I'm not saying the crew intentionally descended below minimums, only that they did. From the leaked report it seems it was only the EGPWS that saved them.
The impression you are giving us readers is that you think the minimums are relevant at all during the missed approach. It wouldn't matter if the minimums were 200' and they descended to 400', the point is they lost control of the fricken aircraft, not the fact that it happened to take them lower than the minimums for the approach that was, by this point, behind them. To say they descended below minimums seems to be missing the much bigger picture.
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Old 17th Jun 2024, 21:58
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Originally Posted by WITCHWAY550
I don't see comments and thoughts on what I am thinking. IF durning the go-around, with the application of TOGA AND if then the F/O pushed down on the elevator AND without any other info relevant to that what makes this any different than the Atlas/Prime 767 accident approaching KIAH? This would be a case of Somatogravic Effect. I understand that the flight instruments displayed the reality as they did on the 767 accident. However I am thinking this may be it and SWA dealt with it as it would if it was reviewed as what it was.
The Atlas FO thought the aircraft was stalling. He intentionally pushed forward on the yoke. He failed so many training programs I can’t remember all of them. Train to proficiency is a bad concept for professional pilots. There need to be limits on how much extra training a pilot receives before being removed from the program.
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Old 17th Jun 2024, 22:42
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Originally Posted by AerocatS2A
To say they descended below minimums seems to be missing the much bigger picture.
They say Asiana 214 flew slower than Vref, but why would someone possibly do that? I can't find a single reference to that airline having special permission to do that... none of this is adding up, make it make sense?! Seems like a huge violation.
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Old 17th Jun 2024, 22:57
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Originally Posted by AerocatS2A
The impression you are giving us readers is that you think the minimums are relevant at all during the missed approach.
Of course minimums are relevant during a missed approach. Had the aircraft been flown competently the aircraft would not have descended below minimums and would not have been in an uncontrolled dive. That does not mean that I believe a descent below minimums was the cause of the uncontrolled dive.

This unproductive discussion seems to have been started by my post that said "Having read the leaked report, and looked at the speed and altitude profile for the excursion below minimums, I find the crew performance far more alarming than the "clickbait" is alarmist."

Perhaps, instead of the euphamistic expression "excursion below minimums" , I should have been more direct as some later posters have been.





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Old 17th Jun 2024, 22:57
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S-767. Yes all true and the absolute obscene event was this F/O working the system. Why wasn’t or still is no PRIA. Going back to the sensory issue it doesn’t matter if you are descending as Prime was or pitched up, once the rapid acceleration occurs you may feel as if you have excessive pitch up and then, without scan and interpretation of the instruments, you react. Just a thought and definitely without knowing any more than anyone else, probably less.
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Old 18th Jun 2024, 00:05
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Originally Posted by EXDAC
This is the best I can do for data for this flight. A KML file was exported from ADS-B exchange and imported into GE. The data is low resolution and has other limitations but I see no missed approach climb before the uncontrolled dive. (Please note that the x axis of the elevation profile is along path distance not time.)


There seems to be a slight change in the profile right before the lowest decent point when you enlarge the graph. I would not call it a climb but a possible pitch change to level and then a decent?
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Old 18th Jun 2024, 08:32
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EXDAC, as mentioned on AVherald, there's 16 seconds missing in the trace. That's where the shanigans occurred.

My reading is this:

They commenced the approach. As shown on the trace, they descended at a nice ROD down towards the MDA. The FO decided to Go Around, which he called. They don't go below the MDA.

We're now in the 16 second blackout. The FO hits the TOGAs, the MAX goes to Max power (Boeing 2000ft/min climb first push, anyone?) and there's a hefty nose-up pitching moment. Jet starts climbing.

FO gets startled/frightened by this pitchup (Somatogavic illusion?), stuffs the nose down, sees the speed increasing and pulls the power off. Jet stops climbing and starts descending.

GPWS wakes up and says uh oh, "Don't Sink" (Missed Approach Mode 3?) and "Pull Up". Jet now descending at 4400fpm towards the water.

Captain steps in and tells FO to "climb and turn left" (missed approach procedure). FO realises what's going on/follows orders, firewalls the throttles and climbs, more Max Powering going on and jet climbs at 8500fpm after bottoming out at 400ft.

Nothing to do with the MDA.
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Old 18th Jun 2024, 09:11
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Originally Posted by Capn Bloggs
EXDAC, as mentioned on AVherald, there's 16 seconds missing in the trace. That's where the shanigans occurred.

My reading is this:

They commenced the approach. As shown on the trace, they descended at a nice ROD down towards the MDA. The FO decided to Go Around, which he called. They don't go below the MDA.

We're now in the 16 second blackout. The FO hits the TOGAs, the MAX goes to Max power (Boeing 2000ft/min climb first push, anyone?) and there's a hefty nose-up pitching moment. Jet starts climbing.

FO gets startled/frightened by this pitchup (Somatogavic illusion?), stuffs the nose down, sees the speed increasing and pulls the power off. Jet stops climbing and starts descending.

GPWS wakes up and says uh oh, "Don't Sink" (Missed Approach Mode 3?) and "Pull Up". Jet now descending at 4400fpm towards the water.

Captain steps in and tells FO to "climb and turn left" (missed approach procedure). FO realises what's going on/follows orders, firewalls the throttles and climbs, more Max Powering going on and jet climbs at 8500fpm after bottoming out at 400ft.

Nothing to do with the MDA.
I never flew the max, but I did fly the Classic and I believe this will depend on whether the automatics were in or not. To add to the excellent post above for those unfamiliar with the 737.

IF AP and AT were in, on the first push of TOGA the autopilot disconnects and the autothrottle will command sufficient thrust for a ~1000 to 2000fpm climb. It will remain armed for the level off. Second TOGA push gives you full chat.

IF the PF was hand flying then the AP and AT would be off and thus the power setting is down to the PF setting the thrust. I used to brief that I would initially set 85-88% N1 (I think - it has been a long time!) but of course I have no idea what this would be on a Max.

In either case, an inadvertent double push or firewalling the thrust levers (instead of a “Boeing arm” as I was trained) would potentially lead to the scenario you propose…. but really should not, the GA in the 737 is fairly benign particularly if you think about power settings.
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Old 18th Jun 2024, 10:13
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Originally Posted by Capn Bloggs
EXDAC, as mentioned on AVherald, there's 16 seconds missing in the trace. That's where the shanigans occurred.
The AV Herald article says "According to ADS-B Data the aircraft descended normally through about 950 feet MSL at 05:12:31 with a sink rate of about 800-1000 fpm, at 05:12:47 however the aircraft is seen climbing through 875 feet MSL at a high climb rate."

I did not see any statement that suggests there was 16 seconds of data missing but I have not read all the comments.

In the ADS-B Exchange data between 12:31 and 12:47 I see data points at 12:35, 12:39, 12:41, 12:43, and 12:46. To the best of my knowledge all those points are included in the profile graphic previously posted.

Edit to add - The graphic, which does not depend on speculation about what happened during a "data blackout", shows a continuous descent below MDA with rapidly increasing airspeed.

Last edited by EXDAC; 18th Jun 2024 at 10:56.
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