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If a pilot ejects, what is the autopilot programmed to do? (2018)

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Re: If a pilot ejects, what is the autopilot programmed to do? (2018)

#33
> The only victim of the accident was Wim Delaere, a computer science student reported to have been either 18 or 19 years old.[4][5][1] He was sleeping alone after celebrating the end of his university exams the previous day when the MiG crashed and killed him at 10:30 am. His mother and brother were shopping for groceries in Kortrijk, and his father was working in Ypres.[4]

From the linked Wikipedia article on one of the answers.

What an unlucky kid.

https://en.wikipedia.org/wiki/1989_Belgium_MiG-23_crash

Re: If a pilot ejects, what is the autopilot programmed to do? (2018)

#34

A pilot would only eject if the aircraft was uncontrollable with no reasonable hope for recovery. Unlikely the autopilot can do anything deliberate at that point.

Yes, but the autopilot should have some kind of contingency programming in case the pilot is mistaken about the aircraft being unflyable.

Even in that case this is a military aircraft, one of the most highly prized secrets many nations hold. Probably the most reasonable response to an ejection the aircraft could take is to nose dive into the ground and slam the throttle to afterburners, which isn’t far of what will happen naturally as soon as the pilot isn’t asking the plane to stay straight and level.

Re: If a pilot ejects, what is the autopilot programmed to do? (2018)

#35
I was astonished at the claim that pilots ejecting can lose half an inch of height due to spinal compression induced by the G-forces. Claims seem to be borne out:

https://www.forcesnews.com/news/can-ejecting-aircraft-make-p... https://www.quora.com/Do-pilots-lose-height-when-they-eject-...

Re: If a pilot ejects, what is the autopilot programmed to do? (2018)

#36

Earlier quoted context omitted.

If this was possible it would just be part of regular flight control laws and would be used to avoid becoming uncontrollable in the first place.

Huh? If I'm the human pilot, I can pull the ejection lever for multiple reasons, including my just being an idiot. The plane, after I eject, should do something reasonable. Maybe it * starts broadcasting a mayday? * crashes into the nearest large body of water? * attempts to fly itself back to base (we have the technology)? I mean, it has to do something and flying straight and level until it runs out of fuel is unli…

I dunno, the current approach seems quite reasonable. In the grand scheme of things the overwhelming majority of the Earth's surface is empty space where a plane crash is unlikely to cause much damage. You also have the complication that military pilots usually try to make sure their plane will crash in a "safe" area before they eject - many have died because they waited too long to eject trying to avoid a populated area. Giving the plan a mind of its own after they pull the handle would be unlikely to go over very well. I believe the scenario of a pilot ejecting from a perfectly good plane that keeps flying for more than a few seconds has only happened perhaps a dozen times in the entire history of aviation? Not really worth worrying about.

Re: If a pilot ejects, what is the autopilot programmed to do? (2018)

#37

A pilot would only eject if the aircraft was uncontrollable with no reasonable hope for recovery. Unlikely the autopilot can do anything deliberate at that point.

Unlikely, you say? That's why it's being discussed. Like, if a pilot ejected because the engines stop, but the control surfaces still work... Maybe the plane avoids a kindergarten on its dive to the earth-sky interface.

Re: If a pilot ejects, what is the autopilot programmed to do? (2018)

#38

Earlier quoted context omitted.

If this was possible it would just be part of regular flight control laws and would be used to avoid becoming uncontrollable in the first place.

Huh? If I'm the human pilot, I can pull the ejection lever for multiple reasons, including my just being an idiot. The plane, after I eject, should do something reasonable. Maybe it * starts broadcasting a mayday? * crashes into the nearest large body of water? * attempts to fly itself back to base (we have the technology)? I mean, it has to do something and flying straight and level until it runs out of fuel is unli…

> The plane, after I eject, should do something reasonable.

There’s a good chance that it can't, and its not impossible that trying to do something reasonable combined with damage that led to and/or resulted from ejection could make things worse.

> starts broadcasting a mayday?

Great idea for peacetime over the homeland, maybe a very bad idea for military operations over contested or enemy territory.

> crashes into the nearest large body of water?

> attempts to fly itself back to base (we have the technology)?

If either of these are useful in a nontrivial share of ejections (except perhaps the former in conditions where it takes no special effort), then there is a serious problem with the training of the people pulling ejection handles and that needs to be fixed, rendering the action not valuable.

> Why would it be controversial to say "Look, guys, we should decide what the plane does after the pilot ejects. Maybe the best policy is just flying same course and speed until fuel exhaustion, but we should choose this policy, not default into it without consideration."

Because ejection is an action chosen when you can no longer meaningfully say what the plane does in any significant way. That’s the whole purpose. If it it is useful to address this question then you have a bigger problem that you need to urgently fix first.

Re: If a pilot ejects, what is the autopilot programmed to do? (2018)

#39
post #35

I was astonished at the claim that pilots ejecting can lose half an inch of height due to spinal compression induced by the G-forces. Claims seem to be borne out: https://www.forcesnews.com/news/can-ejecting-aircraft-make-p... https://www.quora.com/Do-pilots-lose-height-when-they-eject-...

Making sure that the consequences are well-publicized also has the useful side-effect of making sure that ejection is regarded as a last resort.

Re: If a pilot ejects, what is the autopilot programmed to do? (2018)

#40

A pilot would only eject if the aircraft was uncontrollable with no reasonable hope for recovery. Unlikely the autopilot can do anything deliberate at that point.

At the very least, something to keep the flight path predictable would make sense, to give the pilot a chance to point the plane at a "safe" area to crash in before pulling the lever. I remember reading several stories of pilots taking "where is the plane going to crash" into account for their ejection decision or last moves before ejection.

There were also several incidents where a pilot ejected because the plane was somewhat controllable but it was clear it couldn't be landed safely. At least one of them where they had tens of minutes of controlled flight before ejecting (they flew it over the ocean to minimize the risk of collateral damage).

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