The Crash of United Flight 232 (2017) • Hacker News Board

Re: The Crash of United Flight 232 (2017)

#51

Post by mlyle » Tue, Sep 03, 2019, 1:14 AM UTC

jacquesm wrote: post #14

jonas21 wrote: post #10

With all the attention given to the 737 MAX lately, it's easy to forget that airline travel is dramatically safer today than it was just 30 years ago when this incident took place. Fatalities per revenue passenger-mile have decreased by a factor of 15x from 1989 to 2018 (and 54x from 1970 to 2018) [1]. [1] https://theblogbyjavier.com/2019/01/02/aviation-safety-evolu...

Now assume Boeing and the FAA did their jobs and re-calculate.

Remember that the failure we complain about on the 'MAX was an effort to improve margin on the design (to make over-rotation and nose rising on climb a lot less sporty on a heavier aircraft)... that was completely screwed up by both Boeing and regulators.

Mistakes will be made; automation in the name of safety has killed people and will continue to kill people. But overall automation and resource management in the cockpit have conspired to make aviation incredibly safe compared to the past.

Re: The Crash of United Flight 232 (2017)

#52

Post by mlyle » Tue, Sep 03, 2019, 1:19 AM UTC

joshAg wrote: post #30

Aeolun wrote: post #26

Earlier quoted context omitted.

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…

Yah. The thing is, long-period oscillation modes (phugoid, etc) exist in aircraft but are so readily controlled by pilots with conventional controls that they mostly don't matter from a certification standpoint (and would be difficult to avoid, anyways).

But jet engines are slow enough that any significant control of 10-30s period oscillations with engine thrust alone would be a real, real challenge.

Re: The Crash of United Flight 232 (2017)

#53

Post by DataJunkie » Tue, Sep 03, 2019, 1:26 AM UTC

jonas21 wrote: post #10

With all the attention given to the 737 MAX lately, it's easy to forget that airline travel is dramatically safer today than it was just 30 years ago when this incident took place. Fatalities per revenue passenger-mile have decreased by a factor of 15x from 1989 to 2018 (and 54x from 1970 to 2018) [1]. [1] https://theblogbyjavier.com/2019/01/02/aviation-safety-evolu...

Yes, especially in the US. I think the only crash of a large commercial airliner since 9/11 was AA 587. In the 80s/90s it seemed to happen once a year.

Re: The Crash of United Flight 232 (2017)

#54

Post by DataJunkie » Tue, Sep 03, 2019, 1:28 AM UTC

IIRC, several policy changes resulted from this crash:

- Pathway lighting for exits

- Reminding passengers that the nearest exit may be behind you (not all airlines remind you)

- Changes in how lap children are dealt with during an emergency.

Re: The Crash of United Flight 232 (2017)

#55

Post by dev_tty01 » Tue, Sep 03, 2019, 2:08 AM UTC

matt-attack wrote: post #36

steelframe wrote: post #35

Earlier quoted context omitted.

It seems to me the reason is simply that it wasn't anyone's job to make sure there was really great footage of the crash. Everyone was too busy preparing to respond to an imminent disaster in which nearly 300 lives were, in all probability, about to be lost. "Hey Bob, you have that VHS recorder stowed away somewhere in the locker room, don't you? This guy on something called a website 30 years in the future is going…

I'd image it would have provided more than just lulz. It'd think a video like that would be of enormous engineering value in crash-dynamics.

They may have felt it would be too disrespectful to film the death of so many people.

Re: The Crash of United Flight 232 (2017)

#56

Post by klausa » Tue, Sep 03, 2019, 2:15 AM UTC

DataJunkie wrote: post #53

jonas21 wrote: post #10

With all the attention given to the 737 MAX lately, it's easy to forget that airline travel is dramatically safer today than it was just 30 years ago when this incident took place. Fatalities per revenue passenger-mile have decreased by a factor of 15x from 1989 to 2018 (and 54x from 1970 to 2018) [1]. [1] https://theblogbyjavier.com/2019/01/02/aviation-safety-evolu...

Yes, especially in the US. I think the only crash of a large commercial airliner since 9/11 was AA 587. In the 80s/90s it seemed to happen once a year.

Asiana 214 was arguably a "crash of a large commercial airliners", though thankfully only 3 people died.

Re: The Crash of United Flight 232 (2017)

#57

Post by dralley » Tue, Sep 03, 2019, 2:32 AM UTC

FabHK wrote: post #28

Would ditching (assuming there was a large body of water near) or landing in a huge cornfield (like Ural Airlines 178 out of ZIA (Moscow-Zhukovsky)) have made it better or worse?

Disclaimer: this is total speculation from someone completely unqualified to speculate about aviation

Given the violence of the crash due to the total lack of fine control, likely worse.

A fire in the cornfield could have killed many more people as would the lack of emergency firefighting and medical attention.

A plane that broke apart in the water would likely just lead to most passengers quickly drowning. It might work if the plane remained intact, but that requires landing level and slow, something they had no ability to control.

Re: The Crash of United Flight 232 (2017)

#58

Post by Ono-Sendai » Tue, Sep 03, 2019, 2:39 AM UTC

libria wrote: post #41

dclowd9901 wrote: post #16

Earlier quoted context omitted.

Amazing how that turns out. Like when Sulley had to ditch that flight into the Hudson, and just so happened to be an instructor of water landings. What are the odds?

Could be some survivor bias here. One 747 Max happened to have a jumpseat pilot who knew how to fix the MCAS issue and the plane flew on without issue and thus without much media coverage. [1] Presumably, 2 other 747 Max's didn't have enough SME's on board to save them and crashed. [1] https://www.theatlantic.com/notes/2019/03/jump-seat-pilot-an...

737

Re: The Crash of United Flight 232 (2017)

#59

Post by bdash » Tue, Sep 03, 2019, 3:06 AM UTC

matt-attack wrote: post #34

One thing I never understood as a kid, was why wasn't there better footage of a crash. Many people at the airport knew the plane was coming in, and they had plenty of time. Yes this wasn't 2019 where everyone has a camera in their pocket, but nonetheless I always thought the could have done better than the crazy shot through the chain-link fence.

From the talk by Captain Al Haynes (http://clear-prop.org/aviation/haynes.html):

> We only gave them two minutes to line up for runway 22. They were all set up for runway 31. And when I told Kevin we saw this runway ahead of us, and that's where we were going to land, he had two minutes to get the equipment off the runway. They were actually positioned on that runway, and we could see them moving off that runway. That's the reason the video is no better than it was. With all the notice we had, everyone was set up for runway 31. The two hangars that are built right off to the left of runway 22 were built after the airport was closed, and you can't see the runway from the tower. And that's where the operator was. So he went clearing down the steps, and if you've ever tried to get down tower steps in a hurry, it's a long way down, and that's as far as he could get, before we got there.

Re: The Crash of United Flight 232 (2017)

#60

Post by quickthrower2 » Tue, Sep 03, 2019, 3:21 AM UTC

libria wrote: post #41

dclowd9901 wrote: post #16

Earlier quoted context omitted.

Amazing how that turns out. Like when Sulley had to ditch that flight into the Hudson, and just so happened to be an instructor of water landings. What are the odds?

Could be some survivor bias here. One 747 Max happened to have a jumpseat pilot who knew how to fix the MCAS issue and the plane flew on without issue and thus without much media coverage. [1] Presumably, 2 other 747 Max's didn't have enough SME's on board to save them and crashed. [1] https://www.theatlantic.com/notes/2019/03/jump-seat-pilot-an...

The survivor bias being, a regular plane crash story won't make it to HN page 1.