Not_Delta 191

[3WE]

For some reason I do not_remember this crash: https://www.ntsb.gov/investigations/...ts/AAR9503.pdf

However, I find it extremely interesting.

1. It is very similar to Delta 191, and I’m always interested in my hometown Ozark 809 FH-227 crash.

2. BUT, this occurred after we supposedly fixed everything with quadrant-based wind shear alerts and procedures and sim training.

3. Much like Delta 191, this was a rapidly-developing, small storm.

4. Subtlety different, the plane ahead reported a smooth ride (the plane ahead of 191 did not REPORT anything, but supposedly encountered a severe shear. The plane ahead of 809 went around)

5. In both cases, some weather reporting was missed, but, unlike 191 and Ozark 809, the meteorologists seemed to be tracking mundane build ups. With 191, supposedly meteorologists were saying, “wow, this sucker is getting strong” in the minutes before the crash. With 809 a big system was already warning level, and it was more about its arrival on the approach path.

6. This crash and 809 both make mention of “walls of water”. I wonder if that has ever been researched as a possible signature that might be teased out of radar?

7. Very similar to 191, the crew identifies the activity, and discusses potential shear. With 191, the speed increase is noted but not immediately addressed. Here, the PM says 20 knots fast, go around. (809 discusses the weather, but downburst wind shear isn’t really “a known thing” back then.)

8. In both jet cases, the flying pilots are faulted for letting the nose drop and not extracting full performance, (with my favorite “yeah but”) the stall warning did activate which means they weren’t not_trying to climb. With 191, TOGA power was called for. Here, they were supposedly using a “normal go-around” power instead of some slightly higher setting. They were cited as also being slow to get the gear up. And again, this crash was after the development of the “Delta 191 procedures and sim trainings”. (809 did not get a heavy duty performance analysis and may not have had much FDR data.)

9. It’s interesting to contrast a big, lumbering jumbo jet and a “sporty” DC-9-31, but maybe JT-8Ds spool up slow, much like RB-211s.

10. The estimated wind shears were fairly similar and very impressive in this and 191.

11. Similar to 809, the pilots survived, with a similar death toll.

12. I don’t know the exact details, but terminal Doppler radar, with shear detection wasn’t installed yet, and I guess there was no on board shear detection vs nowadays.

13. I’ll have to think/study more- I always felt that 191 was a fumble as the meteorologists were noticing the storm and because in Texas, they have those intense, high-base “dry” thunderstorms” that act like ITS. The Carolina’s (and Flyover’s) are much more juicy- but it almost feels that the US Air encounter was unavoidable given everything. The 809 crash happened 2.5 miles short of the runway which hints at particularly hellacious winds.

[Evan]

5. In both cases, some weather reporting was missed

In the case of 1016, a windshear warning was issued by LCW but on a different frequency than the one they were using (facepalm).

8. In both jet cases, the flying pilots are faulted for letting the nose drop and not extracting full performance, (with my favorite “yeah but”) the stall warning did activate which means they weren’t not_trying to climb. With 191, TOGA power was called for. Here, they were supposedly using a “normal go-around” power instead of some slightly higher setting. They were cited as also being slow to get the gear up. And again, this crash was after the development of the “Delta 191 procedures and sim trainings”. (809 did not get a heavy duty performance analysis and may not have had much FDR data.)

1016 was executing a go-around, not a windshear escape maneuver, so the standard go-around power setting was used (though EPR was a bit below even that).

12. I don’t know the exact details, but terminal Doppler radar, with shear detection wasn’t installed yet, and I guess there was no on board shear detection vs nowadays.

There was only LLWAS detection but it was apparently enough for the tower to issue a windshear warning. Just not on the right frequency (facepalm). Doppler TDWR was mandated by Congress in 1995 (won't happen again...).

The fatal error here seemed to have been the pitch reduction, which seems inexplicable to those who believe 'universal airmanship' will always save the day but understandable to those who acknowledge human factors and embrace the humility of human limitations. Not surprisingly, neither pilot could recall the pitch down command, a common report among surviving pilots who have done inexplicable things under stress and disorientation. The most likely culprit was somatogravic illusion, causing the captain to sense that the F/O was climbing too steeply in the go-around.

The moral of the story, of course, is to go-around sooner, to avoid observed weather with wind-shear potential, better safe than sorry. But we also have far greater ability to detect windshear and downbursts both onboard and on the field than we did in the early 90's. So I think we are unlikely to see these sort of crashes in the current age occurring at most modern commercial airports.

[3WE]

The most likely culprit was somatogravic illusion, causing the captain to sense that the F/O was climbing too steeply in the go-around.

Your unnatural fixation on some things never ceases to amaze me.

Could dangerously slow speeds, stick shakers, and downburst turbulence maybe affected the pitch situation?

I also don’t buy in to your mindset that “it was a go around procedure” which prevented them from surviving. Both “procedures” include lots of power, critical performance and, I dunno FTGDA. I can’t see them devoting great effort to hold the power back. I know the report mentions this, but it wasn’t some goofy conscious decision that we won’t use a bit more power and must not pull up. I recall that maybe JT-8D airplanes had the ability to damage engines, and not all the automatic stuff.

Finally- what I see in the wind shear reports is kind of unremarkable. It they heard them, my bet is that they would have proceeded right to the 20 kt gain.

Like Delta 191, they were “tuned in” to possible shear. Like Delta 191, it was a sudden, extreme event while the plane ahead landed fine. The human factors of riding a bicycle give one a slightly different view.

[Evan]

Your unnatural fixation on some things never ceases to amaze me.

It's in the report. You should read it.

And maybe you have a better explanation as to why a very experienced ex-fighter pilot would tell his F/O to push the nose down while climbing out like that.

[3WE]

It's in the report. You should read it.

And maybe you have a better explanation as to why a very experienced ex-fighter pilot would tell his F/O to push the nose down while climbing out like that.

1. I do have a better explanation.

2. But, you are right, experienced pilots make control inputs based off of feelings of acceleration. Definitely not airspeed or stall warnings.

[Evan]

Definitely not airspeed or stall warnings.

Or altitude. I heard somewhere that when you push the nose down at 200ft you are landing, not going around.

[Gabriel]

Or altitude. I heard somewhere that when you push the nose down at 200ft you are landing, not going around.

On the other hand, if you instead of push the nose down at 200ft you stall at 200 ft ___________ (fill in the blank).

[Evan]

On the other hand, if you instead of push the nose down at 200ft you stall at 200 ft ___________ (fill in the blank).

You pull up in downburst. Up to stickshaker and in and out of stickshaker until you exit the thing. You definitely do not apply sustained airplane-nose-down pitch as the captain called for here. If the stall warning is brought on by downburst and a negative AoA, how is reducing pitch going to save you? Of course, you'll need all the power you can get. If those cans on the back were solid rocket boosters, you'd want to pull up relentlessly. If they are JT8D's left at 1.8 EPR, you do what you can I guess, but you definitely do not point it down at that height.

The problem here was situational awareness. They were wary of windshear and prepared to go-around. When the airspeed jumped by 20kts they did go around. But it was too late to avoid downburst. I'm pretty convinced the captain here was focused on stall avoidance in the go-around and was not mentally aware that they had entered a downburst cell. I think he mistook the stickshaker warnings for conventional stall, mistook somatogravic illusion for a rapid increase in pitch, put two and two together and told the F/O to 'push it down'. I don't think instruments made it into that equation, as they often don't during time-compressed upsets. It was good 'ol seat of the pants stick 'n rudder airmanship.

If he had full awareness of the situation, he would have called for TOGA and fly the stickshaker, and maybe pray for lift. In the end, when asked why he had called for negative pitch input, he could not recall having that thought. Ladies and gentlemen, behold the mysteries of the vastly experienced human mind under stress and confusion.

And again, moral is: don't fly into this stuff.

[3WE]

And again, moral is: don't fly into this stuff.

Not the worst thought, but go to a busy airport some day when a storm rolls through and watch Flightaware and listen to ATC…they often cut it really close.

https://www.youtube.com/watch?v=D5CLNC1kPsQ

[3WE]

If the stall warning is brought on by downburst and a negative AoA, how is reducing pitch going to save you?

The problem here was situational awareness.

I'm pretty convinced the captain here was focused on stall avoidance in the go-around and was not mentally aware that they had entered a downburst cell. I think he mistook the stickshaker warnings for conventional stall, mistook somatogravic illusion for a rapid increase in pitch, put two and two together and told the F/O to 'push it down'. I don't think instruments made it into that equation, as they often don't during time-compressed upsets. It was good 'ol seat of the pants stick 'n rudder airmanship.

If he had full awareness of the situation, he would have called for TOGA and fly the stickshaker, and maybe pray for lift.

Okay.

[3WE]

https://youtu.be/dKwyU1RwPto?si=XuZoLewfQvi55lDr


https://youtu.be/HY7pH3fzsvY?si=dORYduWDcWkLMxiL


[Delta 191 depection] See how the somatogravic illusions, fear of a negative AOA stall and unawareness that they are in a microburst lead the pilots to nose down.

Strikingly similar, I tell ya.

And one subtlety: Pilots in the time of 191 were aware of a theory that a downdraft, hitting the earth might generate a speed increase followed by speed decrease (with a downdraft in the middle) that was consistent with a number of stormy-weather, low-altitude crashes. (727 MSY, et al)

[Evan]

https://youtu.be/dKwyU1RwPto?si=XuZoLewfQvi55lDr


https://youtu.be/HY7pH3fzsvY?si=dORYduWDcWkLMxiL


[Delta 191 depection] See how the somatogravic illusions, fear of a negative AOA stall and unawareness that they are in a microburst lead the pilots to nose down.

Strikingly similar, I tell ya.

And one subtlety: Pilots in the time of 191 were aware of a theory that a downdraft, hitting the earth might generate a speed increase followed by speed decrease (with a downdraft in the middle) that was consistent with a number of stormy-weather, low-altitude crashes. (727 MSY, et al)

What is similar is that they both chose to fly into potential downburst. Both were aware of the possibility. The captain of 191 had already made cautious weather diversions, and had almost 30,000 hours without a magenta line.

But, aside from the fatal decision to continue, the crew of 191 did not make any egregious errors. You simply cannot beat microburst sometimes. The captain called for power at first by saying “push it way up” instead of “TOGA” but aside from that, pitch was increased correctly (I do not see any stall warning there). The pull up is in fact what saved some of the passengers as it slowed the descent to 10fps, allowing the plane to touch down intact with gear attached. It was the rollout that killed them after striking obstacles. If it had been an empty field, they would have walked away.

For the third time, the moral is: don’t fly into this stuff and, thanks to windshear detection technology and widespread respect for microburst, the only other microburst crash of a major airliner since 191 was 1016.

That’s what they have in common.

[3WE]

Did you watch the video or read the report? There’s two small nose overs on 191 (when they weren’t pulling up to stick shaker) and they are cited as contributing factors.

A huge ass wind shear, greater than ever reported before, is another big contributing factor.

And you don’t have to leave the bubble: put a 70 kt shear in at 600 feet and fly a heavy jet through on MSFS. You might end up landing gently, 0.25 miles short of the runway. The best survival trick is carrying extra knots, and firewalling the wimpy plastic power lever the instant the airspeed bobbles up.

A bicycle does add some reality as motion, maintaining things and maybe dealing with bumps isn’t a static arm chair.

By the way: Read the FCOM as much as you want, but pulling up aggressively right to, but not beyond stick-shaker while dealing with significantly varying up and down vertical speeds and winds and and tons of turbulence in other directions, plus sudden, serious airspeed decays, is one hell of a seat-of-the pants, situational awareness, stick-and-rudder undertaking. Repeat the bicycle vs armchair jab.

[Evan]

Repeat the bicycle vs armchair jab.

Until your dying day, I know.

Look, we are not disagreeing here. The only reliable way to deal with microburst is to stay well away from it, which, thanks to modern developments, is not difficult.

Once in it, all you can do is power up, pull up, and pray (and, if you find a spare moment, curse yourself for being there at all).

Maintaining a healthy power setting above idle might help, but I doubt it and it's hard to do when you are trying to catch the GS from above with a speed restriction.

But 1016 pushed the nose down. ANU pitch. The only plausible explanation for that is scrambled situational awareness.

[3WE]

The only

I thought you knew that I have a thing about phrases and words like that.

But oddly enough, my objection is your blindness to some extremely plausible additional alternatives.

And the bicycle analogy fits it all so well.