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If a pilot uses their ejector seat during flight, what is the autopilot programmed to do?

As a developer myself, I'd want to build in a way for the plane to try and save itself if possible (to save money) by auto-landing, or at the very least, calculate the nearest least-populated area for a crash-landing. So I'm wondering if anything like this is even written into the software.

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    $\begingroup$ No software needed :D $\endgroup$
    – user14897
    Jun 22, 2018 at 15:24
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    $\begingroup$ Not many situations where the pilot needs to eject, and the autopilot is active -- usually you'd have that off if: being shot at, doing high-energy maneuvers, landing or taking off, etc. And once you need to eject, activating a near-useless autopilot is likely to be the last thing on your mind. $\endgroup$
    – Zeiss Ikon
    Jun 22, 2018 at 16:45
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    $\begingroup$ @ceejayoz Ribbing in person would have been a lot better than at his funeral, so I'd say whatever he got was worth it. $\endgroup$
    – Ron Beyer
    Jun 22, 2018 at 17:31
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    $\begingroup$ I suspect the military preferred option for some aircraft (e.g. classified stealth aircraft) would be to cause the most self-destructive landing possible - the last thing they want is for the aircraft to be recovered by the enemy. $\endgroup$
    – abligh
    Jun 22, 2018 at 18:15
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    $\begingroup$ @ZeissIkon And once you need to eject, activating a near-useless autopilot is likely to be the last thing on your mind. Ofcourse, the AutoPilot could activate on/by the pilot's eject button/switch/handle. If it would do any good is another matter. $\endgroup$
    – RobIII
    Jun 23, 2018 at 9:16

5 Answers 5

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I would want to build in a way for the plane to try and save itself if possible (to save money) by auto-landing

Had the situation allowed saving the airplane the human pilot would definitely have tried that first. The fact that a trained fighter jet pilot decided to eject from an aircraft knowing that the ejection was a last resort and could be deadly, signifies that the plane was not able to be flown safely anymore.

On top of numerous irrecoverable problems at that point, one of the most significant issues is the fact that ejection destabilizes the flight path and the increased drag (because there is no longer a canopy on top) makes it even harder to safely glide that jet, let alone land it somewhere.

There is nothing much autopilot can do at that point.

There have been two famous incidents that are related to your question but afaik neither of them involve Auto Pilot.

It's just like saying I know the airplane can be saved but my computer will take care of it, I'm outta here. See you at the Court Martial.

Some commentators have noted that I did not answer one basic question:

Don't forget to answer the question "If a pilot ejects, what is the autopilot programmed to do?", even if the question seems moot

This question is too broad: there are numerous models of fighter jets all around the world, built by a number of manufactures and internal details of which are closely guarded secrets. You are not going to generally find out a manual on the web listing all the actions that the autopilot software will perform after a bail out. If the OP can narrow down the question to a certain model one can research and try to find something but I don't believe its going to be an easy find. Hence I'm sorry I don't have an answer to that question. I hope someone more knowledgeable goes ahead and posts an answer to that.

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    $\begingroup$ Auto-landing safely over enemy territory is also counterproductive :) $\endgroup$
    – user14897
    Jun 22, 2018 at 16:15
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    $\begingroup$ Yeah, thank you for letting me eject on my side of the border, here take our airplane and all its secrets on your nearest runway $\endgroup$
    – Hanky Panky
    Jun 22, 2018 at 16:33
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    $\begingroup$ Or in peacetime, the plane wreaks havoc by going to the nearest airport and landing, ignoring air traffic control, deciding for itself which runway is active, and disregarding whatever is happening in that airspace and on the ground. $\endgroup$
    – rclocher3
    Jun 22, 2018 at 16:39
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    $\begingroup$ Don't forget to answer the question "If a pilot ejects, what is the autopilot programmed to do?", even if the question seems moot. $\endgroup$
    – Keeta - reinstate Monica
    Jun 22, 2018 at 19:34
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    $\begingroup$ You've explained why you think autopilot would be useless, but haven't actually answered the question: "what is the autopilot programmed to do?". The answer may be "nothing", because of reasons stated in your answer, but there may be more to it. You should at least try to answer the question. $\endgroup$
    – Aubreal
    Jun 22, 2018 at 20:08
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To add some context to the other answers...

Ejection is not a safe thing to do.

The two most popular ejection systems today, the ACES II and Martin-Baker, have around a 90-92% success rate... the definition of success being the person lived. Most ejections result in some injury to the person, as it is a fairly violent activity, with a brief 20g impact when the seat fires.

Almost all ejection occupants will suffer some form of spinal compression, typically they'll lose half an inch of height. If the person doesn't follow protocol exactly, they may lose an arm on the way out. If the head isn't perfectly in line with the spine, the neck can be broken.

Ejection is a measure of last resort, to be used only if the only other option is certain death.

So it's pretty much a given if the crew member fires the ejection seat, there is no other viable option, and the aircraft is uncontrollable, or will very soon be uncontrollable, by a pilot or an autopilot.

Also, if the aircraft is gyrating wildly, the seat can malfunction, or the occupant can be struck by parts of the aircraft, so waiting until the aircraft is completely out of control isn't a wise move, either.

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    $\begingroup$ That’s a great answer. $\endgroup$
    – Hanky Panky
    Jun 23, 2018 at 17:10
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    $\begingroup$ +1. Ejection is not teleportation. You can get killed/maimed by the aircraft on the way out. $\endgroup$
    – Nelson
    Jun 24, 2018 at 6:07
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    $\begingroup$ Question: Is there a second, less-violent mode for ejection seats if you have perfect conditions? For example the aircraft is fully functional, but you will ran out of fuel and there is only wood/water, so you really cannot land safely, if at all. $\endgroup$
    – Thorsten S.
    Jun 25, 2018 at 10:37
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    $\begingroup$ @ThorstenS.: No, the ejection system is strictly binary: fully in/fully out. Anything else is a malfunction (you don't want to eject halfway, or sort-of-eject and immediately get hit by the rudder). The thing is complex enough without a trim knob ;) $\endgroup$
    – Piskvor left the building
    Jun 25, 2018 at 15:31
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    $\begingroup$ Self destruction sounds like an excellent idea for military planes in contested space (provided it doesn't kill the ejected pilot in the process) $\endgroup$
    – rbanffy
    Jun 25, 2018 at 17:31
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Whatever it was programmed to do at the moment the pilot ejected.

Ejection seats are complex enough without integrating special processing of the event into the autopilot. Since the autopilot can't land even an intact plane on its own, there's nothing it could do to save the plane.

Some ejections are indeed performed from aircraft that could potentially be saved, and have been landed with similar damage. It's a matter of avoiding excessive risks from a gamble for an 80% chance of a safe landing and 20% a violent crash that sets the deck park on fire. For certain historical reasons, many navies maintain an understandable bias against fires on the deck, and would prefer just ditching one plane. On dry land, there's more latitude for crash landings.

As for preventing (or causing) collateral damage on the ground, the only way is for the pilot to point their plane somewhere and pray. The autopilot is a reactive system - it doesn't concern itself with what's wrong or model the aircraft, just corrects what happens, so, possibly counterintuitively, it's often not too bad at controlling a damaged plane.

Since fighter control surfaces are large enough to counteract a lot of damage-induced drag, a working autopilot has a chance to maintain its last heading even with a damaged craft. And that's as good as you could get with the current level of flight automation.

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    $\begingroup$ In particular, when ejecting from large aircraft (eg. bombers) or when the aircraft is currently flyable but shortly won't be (eg. uncontrolled engine fire), it's common to set the autopilot to hold "straight and level" to make ejection easier. If they've got time, the pilot might additionally aim the plane for the nearest large body of water or other unoccupied area. $\endgroup$
    – Mark
    Jun 22, 2018 at 20:15
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    $\begingroup$ @Mark Yeah, fly away from civilization and towards water would be a good last order. Also, in wartime you might like something that causes it to auger in once it's down to a few thousand feet. There's also the plane that can be flown but can't be landed--anything that takes the minimum airspeed high enough that there isn't a runway long enough. $\endgroup$
    – Loren Pechtel
    Jun 23, 2018 at 4:43
  • $\begingroup$ @LorenPechtel: Well when you can land with one wing: theaviationist.com/2014/09/15/f-15-lands-with-one-wing $\endgroup$
    – Joshua
    Jun 25, 2018 at 16:16
  • $\begingroup$ @Joshua Sure, but it needed a lot of runway due to the high landing speed. Had it been a bomber instead, there would probably be nowhere (outside of Edwards) with a long enough runway. $\endgroup$
    – Skyler
    Jun 25, 2018 at 17:08
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    $\begingroup$ @Skyler great and now I'm imagining a situation that involves refueling a 1-winged bomber long enough to make it to Edwards. $\endgroup$
    – Wayne Werner
    Jun 25, 2018 at 20:50
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It generally does nothing. When a pilot ejects from the plane, that bird is screwed beyond saving. There is no autopilot in the world which is sophisticated enough to fly a military plane even when it's fully intact, let alone when it's on fire and going down.

However, as I heard, there was a Su-27 model (or some descendant of the Flanker, maybe just a prototype?) which had a peculiar easter egg: after ejection the onboard voice announcement system (the female voice which warns the pilot to certain things) talked for the last time: "Good bye, and thank you on behalf of the fleet." There was nobody to hear it, and the pilot's helmet has already been disconnected by this time, so it was really just some engineer's idea of a joke. I don't know if it's an actual feature in current Russian naval Flankers.

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    $\begingroup$ Welcome to aviation.SE! Do you have some sources that you can link to? The comment that "there is no autopilot in the world which is sophisticated enough to fly a military plane" is confusing because we know that at least some military aircraft do have them. $\endgroup$
    – Pondlife
    Jun 24, 2018 at 20:48
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    $\begingroup$ This is backwards. A modern fly-by-wire control system is basically an always-on autopilot that gives consideration to the pilot's input. Giving it basic hold modes in addition to maneuvering ones is comparatively trivial. $\endgroup$
    – Chris Stratton
    Jun 26, 2018 at 5:23
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    $\begingroup$ Hmmmm... If an airplane talks to the pilot after he has ejected, does it make a sound? But seriously - there's way too much "I heard this from a guy in a bar who got it from someone who oughta know". Tell you what - take up an Su-27, climb out of the seat (but still in the cockpit, but out of the way of the ejection seat), trigger the seat, stay plugged into the headset, and you tell me what happens next, OK? $\endgroup$
    – Bob Jarvis - Слава Україні
    Jun 26, 2018 at 14:54
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    $\begingroup$ These things are called anecdotes. Anyone looking for solid evidence to everything, go to a technical library. $\endgroup$
    – Tamás Polgár
    Jun 27, 2018 at 2:17
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    $\begingroup$ @Cloud: no worries. The aircraft has an autopilot and will land itself shortly (for sufficiently small values of "land" and sufficiently large values of "crater". :-) $\endgroup$
    – Bob Jarvis - Слава Україні
    Jun 27, 2018 at 11:11
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I imagine there's probably a switch such that over enemy or unknown territory the plane self-destructs. But you don't want this over your own training areas such that some kind of controlled landing may be programmed in when in training mode.

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    $\begingroup$ Military aircraft "self-destruct" is actually kind of boring. It's more of a frying of circuits than a dramatic explosion. $\endgroup$
    – Karl Bielefeldt
    Jun 26, 2018 at 1:30
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    $\begingroup$ This answer seem wrong. Do you have any references to support it? $\endgroup$
    – Dmitry Grigoryev
    Jun 26, 2018 at 9:12
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    $\begingroup$ You're right - you "imagine". There is no "make the airplane explode" switch. $\endgroup$
    – Bob Jarvis - Слава Україні
    Jun 26, 2018 at 14:53
  • $\begingroup$ @DmitryGrigoryev I apologize for not having sources, but these planes are full of technology. Countries go through great lengths to destroy downed planes so that nobody can reverse engineer them. In fact, these events are kept as secret as possible, making finding sources difficult. $\endgroup$
    – Carl
    Jun 26, 2018 at 15:36

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