If a pilot ejects, what is the autopilot programmed to do? (2018)
43 comments
·October 30, 2025ortusdux
I recently learned about the Green Ramp disaster, where the crew ejected from an F-16 under full afterburner, and the jet continued on to collide with several parked airplanes, resulting in 24 fatalities.
"As of 2025, this incident has the largest number of ground fatalities for an accidental crash of an aircraft on U.S. soil. It was also the worst peacetime loss of life suffered by the division since the end of World War II."
hex4def6
It seems like the sensible thing to do would be to fry / erase any IFF and encryption related stuff, but otherwise continue as before.
E.g, if it's already been programmed to fly straight and level, continue to do that. If it's deactivated, stay deactivated.
Just seems like a whole 'nother set of characteristics to test otherwise, as well as adding extra unpredictability. The aircraft is probably damaged / on fire, so its flight characteristics are already going to be extremely different to normal. The best thing in the moment may be to let the aircraft lawn-dart in a field, rather than attempt to get straight and level, and in the process potentially fly over inhabited area or towards a friendly set of aircraft / buildings / vehicles.
pdonis
If the autopilot is engaged, the pilot won't be ejecting, because the aircraft will be in some kind of controlled flight. Autopilots will be disengaging and lighting up a big red light in the cockpit well before the aircraft gets to the point where the pilot would consider ejecting. Remember that ejecting is an absolute last resort, since the pilot is quite likely to be injured and runs a significant risk of being killed in the process of ejecting.
cluckindan
About one in 20 ejections results in death, usually due to low altitude, or being hit/crushed by the seat.
Compare to 20 in 20 jet airplane crashes resulting in death and suddenly pulling that lever might seem a worthwhile risk to take
Spooky23
This thread is a great example of how engineers by nature are tempted to add complexity to nearly any scenario.
ternus
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-...
ern
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.
SoftTalker
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.
RobotToaster
Planes that keep flying after an ejection do happen
https://en.wikipedia.org/wiki/Cornfield_Bomber
https://www.marinecorpstimes.com/news/your-marine-corps/2024...
tekla
These are not equivalent.
The first one, the Airplane was in an uncontrolled spin, the ejection happened to fix it.
tgsovlerkhgsel
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).
bravoetch
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.
the__alchemist
Not necessarily. For example, you'd eject if unable to get as safe landing configuration.
quotemstr
Yes, but the autopilot should have some kind of contingency programming in case the pilot is mistaken about the aircraft being unflyable.
appreciatorBus
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.
quotemstr
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 unlikely to be the optimal value of "something"
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."
jon-wood
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.
whycome
This is silly. And not true. There is no “would” other than your own prediction. What if the pilot deliberately wanted to crash the plane but not do it intentionally?
the__alchemist
If it's a controlled ejection scenario, you try to fly to a specific location, airspeed, heading, and altitude, then pull. It will be in your local-area in-flight guide. The intent is, the plane ends up somewhere away from civilization. This if, of course, only suitable for scenarios where you have this luxury.
bragr
The analysis and conclusions of the responders here (2018) seem pretty invalidated by the 2024 F-35B ejection incident. Maybe more thought should be put into what the autopilot should do?
https://www.marinecorpstimes.com/news/your-marine-corps/2024...
ffb7c5
I think we should make an API call to an LLM with the current GPS location to decide what to do, bonus points if we can mount a forward facing camera and upload the picture as well
cosmicgadget
Thinking about this one (https://theaviationist.com/2025/02/12/ea-18g-growler-crashes...), it seems like after ejection you'd want the plane to lawn dart whenever possible. It allows the pilot to know if it is an okay place to ditch and it minimizes the reverse engineering risk.
I imagine there is a good reason this isn't the way things are though.
darkhorn
I think the most proper thing for the jet should be to destroy itself. In a war enviornment I would not like my enemy to gain intel about my military jets.
crazygringo
I think its high-speed collision with the ground or ocean generally takes care of destroying it. Especially with no pilot attempting to keep it level and slow it down and minimize damage.
yjftsjthsd-h
Not my wheelhouse, but doesn't that involve packing the aircraft with explosives, and wouldn't that involve risk of blowing up if someone else shoots you? Or is there some better way to self-destruct?
estimator7292
One could calculate the amount of energy in a given amount of explosive and smashing into the ground at high velocity. I'm too lazy to do so, but I can tell you they're on the same scale.
A heavy object moving fast has a shocking amount of energy. When such an object impacts the ground, all that energy has to go somewhere.
klysm
Assuming there is an autopilot present, nose diving at max afterburner straight down is probably going to yield a similar result
cosmicgadget
There are probably a number of clever and failsafe ways to divert jet fuel somewhere that would destroy the plane on command.
SoftTalker
Impacting the ground usually does it.
DonHopkins
Jets are usually full of jet fuel that can blow up if someone else shoots you, or they run into the ground.
jojobas
Would you go near a plane that's an electronic signal away from blowing itself up?
Even if mechanical, warplanes get combat damage, and having a system like that could make a difference between survivable and sure death.
dylan604
Maybe bring some strong jamming equipment to prevent the electronic signal from being received?
tekla
TLDR: It does nothing and it should never do anything
> 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