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The Crash of United Flight 232 (2017)

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21–30 of 75 posts

Re: The Crash of United Flight 232 (2017)

#21
"A fireball and smoke rose from the middle portion of the plane as banks of seats began vaulting and somersaulting high above the flames. Some of the banks of seats were thrown far above the fuselage in great parabolas, shot as if from a cannon by the centrifugal force of the aft end of the fuselage swinging in its majestic, flaming arc. What must it have been like to take that ride, alive, aloft, alone, aware, unhurt as yet, and looking down on the green earth?"

Holy shit.

Re: The Crash of United Flight 232 (2017)

#22

I notice that the flight instructor disobeys the captain, who says to says to remove power from the engines, and does the opposite right as they're touching down. Was there ever any thought as to whether that contributed to the loss of life?

I read the wiki article[0] about this after reading the article and found it a lot more informative. It says just before touchdown "Fitch noticed the high sink rate and that the plane started to yaw right again, and pushed the throttles to full power in an attempt to mitigate the high sink rate and level the plane". It seems a more complex situation than him just deciding to apply power to the engines as the right wing would likely have made contact with the ground anyway.

I wasn't able to find any speculation if Fitch could have acted differently and had a better outcome in the official report[1]. The report states that the "captain's acceptance of the check airman to assist in the cockpit was positive and appropriate".

Regarding disobeying the captain we can see from transcripts from the CVR that the captain (probably) knew what Fitch was doing:

    Records: "Close 'em off."

    Haynes: "Left turn."

    Records: "Pull 'em off"

    Fitch: "Nah, I can't pull 'em off or we'll lose it, that's what's turning ya."

    Unidentified: "Okay."

    Fitch: "Back ya’ll!"

    Haynes: "Left, Left throttle, left, left, left, left, left, left, left, left, left, left, left!"

    Ground Proximity Warning System (GPWS): "Whoop whoop pull up. Whoop whoop pull up. Whoop whoop pull up."

    Haynes: "Everybody stay in brace!"

    GPWS: "Whoop whoop pull up."

    Haynes: "God!"

    [Sound of impact, end of recording]
[0] https://en.wikipedia.org/wiki/United_Airlines_Flight_232

[1] https://www.ntsb.gov/investigations/AccidentReports/Reports/... (Discussion of the performance of the flight crew from page 75 [81] onwards)

Re: The Crash of United Flight 232 (2017)

#23

I notice that the flight instructor disobeys the captain, who says to says to remove power from the engines, and does the opposite right as they're touching down. Was there ever any thought as to whether that contributed to the loss of life?

No. It's remarkable that they even got to the runway with such precision.

Re: The Crash of United Flight 232 (2017)

#26

I notice that the flight instructor disobeys the captain, who says to says to remove power from the engines, and does the opposite right as they're touching down. Was there ever any thought as to whether that contributed to the loss of life?

Presumably using only one engine would have prevented the plane from flipping like it did, but it might have smashed into the ground harder or turned into a fireball.

Ultimately it is impossible to say what kind of effect it would have had, though I’m inclined to say it would likely have been better if the thrust was applied equally.

Re: The Crash of United Flight 232 (2017)

#27
post #12

This is one of those classic aviation tales I'm never not going to re-read when they pop up, right there with the Gimli Glider [1] and the various SR-71 stories. [1] https://en.wikipedia.org/wiki/Gimli_Glider

For me it’s BA9 that piques my amazement

“Ladies and gentlemen, this is your captain speaking. We have a small problem. All four engines have stopped. We are doing our damnedest to get them going again. I trust you are not in too much distress”

And for absurdity the one where the pilot was sucked out of the window and the cabin crew had to hold on to him

https://en.m.wikipedia.org/wiki/British_Airways_Flight_5390

https://en.m.wikipedia.org/wiki/British_Airways_Flight_9

Re: The Crash of United Flight 232 (2017)

#29
Air Crash Investigation/Mayday does a pretty good dramatization of this flight:

https://www.youtube.com/watch?v=N-UM-YcwWBc

A similar incident took place in 2003 on a DHL cargo plane after being hit by a surface-to-air missile. Miraculously they did manage to land the plane intact despite the total loss of hydraulics and needing to rely on engine thrust alone to control the plane.

https://en.wikipedia.org/wiki/2003_Baghdad_DHL_attempted_sho...

The Mayday episode might also mention (least from my memory of last watching it) an experimental NASA program developed sometime after this crash that would allow "full airplane control" via computer in the event one more more control surfaces could not be used. It achieved this by translating normal flight inputs into sophisticated throttle manipulation of the engines, just like the pilots on flight 232 did, but with the reflexes and modeling of a computer.

https://www.nasa.gov/centers/dryden/pdf/88794main_PCA.pdf

Re: The Crash of United Flight 232 (2017)

#30
post #26

I notice that the flight instructor disobeys the captain, who says to says to remove power from the engines, and does the opposite right as they're touching down. Was there ever any thought as to whether that contributed to the loss of life?

Presumably using only one engine would have prevented the plane from flipping like it did, but it might have smashed into the ground harder or turned into a fireball. Ultimately it is impossible to say what kind of effect it would have had, though I’m inclined to say it would likely have been better if the thrust was applied equally.

Thrust was applied equally in the cockpit, but jet engines don't respond immediately and don't spool up in sync. Normally that's not an issue because you're not making large adjustments in short spans of time, you can use various control surfaces to compensate for the brief asynchrony, and you're far enough away from the ground to have room to maneuver.

If you remember the Korean airlines flight that crashed at SFO a few years back, the spool up time for the engines came into play as well. The pilots noticed the issue with too little time for the engines to deliver more power before the plane crashed.

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