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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.

Reid
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Cloud
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    No software needed :D –  Jun 22 '18 at 15:24
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    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. – Zeiss Ikon Jun 22 '18 at 16:45
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    I wonder if the auto pilot even knows about the ejection. – user3528438 Jun 22 '18 at 16:46
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    @ymb1 I can't imagine how bad the ribbing Captain Faust got after that must have been. – ceejayoz Jun 22 '18 at 17:20
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    @ceejayoz Ribbing in person would have been a lot better than at his funeral, so I'd say whatever he got was worth it. – Ron Beyer Jun 22 '18 at 17:31
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    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. – abligh Jun 22 '18 at 18:15
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    @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. – RobIII Jun 23 '18 at 09:16
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    Generally, ejection seats are used in a situation where an autopilot isn't going to do much good, i.e. loss of control, parts of airplane missing, aircraft in an unrecoverable spin, etc. No pilot wants to bail out, and it when they do it's because a very bad choice is the best option available. – Bob Jarvis - Слава Україні Jun 24 '18 at 04:09
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    @ceejayoz: Apparently, the ribbing started while he was still parachuting down. "Gary, you'd better get back in it!" – Vikki Jun 24 '18 at 14:11
  • @abligh, military aircraft (at least Russian ones) generally have small explosives that destroy the most classified systems on the airplane (such as IFF). I don't remember with certainty, but they should activate in case of ejection. In any case, the pilot is required to activate them if the airplane has a chance to end up in the enemy hands. – Zeus Jun 25 '18 at 01:13
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    You're assuming that the airplane HAS an autopilot - many fighters don't have, since they have a highly-skilled and trained manual pilot. – RAC Jun 25 '18 at 09:16
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    Upon ejection, I would have the plane do its best to lawn-dart. No need to leave anything to the scavengers. – Tony Ennis Jun 25 '18 at 18:41
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    @RAC Uh, yeah, military fighters definitely have autopilot systems. Missions aren't dogfights from takeoff to landing, and pilots need time during missions to check maps, adjust instruments, and whatever other cockpit management. There is some flying just to get somewhere and AP allows multitasking in those scenarios. There are also ferry flights where you wouldn't want to be manually holding straight and level for hours without a break. – J... Jun 26 '18 at 10:42
  • I'm wondering if anything like this is even written into the software You can keep wondering, as nobody spending Ministry of Defense, or Department of Defense, money on aircraft subsystems will waste their money on such a pointless piece of software. – KorvinStarmast Jun 26 '18 at 13:30
  • Most fighter type aircraft (A-10, F-16, F-15, T-38, T-6) do not have an autopilot. – Java Addict Apr 01 '21 at 01:39

5 Answers5

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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.

Lightness Races in Orbit
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Hanky Panky
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    Auto-landing safely over enemy territory is also counterproductive :) –  Jun 22 '18 at 16:15
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    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 – Hanky Panky Jun 22 '18 at 16:33
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    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. – rclocher3 Jun 22 '18 at 16:39
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    @rclocher3 With those autopilot capabilities, one begins to wonder why a human pilot would be necessary in the first place! – Todd Wilcox Jun 22 '18 at 17:24
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    At least in the first case (Mig 1989 crash) autopilot was involved. From Wikipedia: "At an altitude of 150 meters and descending, the pilot assumed he had a complete engine failure and ejected without incident. The engine had not failed completely, and the aircraft remained airborne, flying on autopilot in a westerly direction" – abligh Jun 22 '18 at 18:14
  • Yes that is true but note that it was a very crude form of autopilot. In R/C aviation we call it a fail safe in hold mode. So all that the system did in that case was to hold the last commands that were given to it. It did not make any adjustments to avoid something. – Hanky Panky Jun 22 '18 at 18:24
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    Don't forget to answer the question "If a pilot ejects, what is the autopilot programmed to do?", even if the question seems moot. – Keeta - reinstate Monica Jun 22 '18 at 19:34
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    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. – Aubreal Jun 22 '18 at 20:08
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    When a car crashes, from my understanding, the ECU will typically turn off the fuel pump such that (additional) fuel is not pumped into any possible fire by the fuel system. Wouldn't it make sense for an aircraft to do the same? At the very least, the flight computer (not the autopilot) could shut down the engine(s), turn off the fuel pump(s) and shut off power. Furthermore, are there really no realistic cases where the autopilot could attempt to crash land the plane? Even I have seen multiple videos where pilots have ejected because of a lack of a safe place to land, e.g. on bird strikes. – AlphaCentauri Jun 22 '18 at 21:25
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    @AlphaCentauri It's definitely feasible to develop. The algorithm for a completely autonomous transition from arbitrary point in the air to parked on the tarmac just isn't part of current autopilots, even though most of the basic building blocks (nav, autoland) required to put it together are. – Therac Jun 23 '18 at 13:18
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    Good answer. I'd also add that a USAF DC-3 in 1957 landed itself perfectly when it ran out of fuel and the crew bailed out http://www.dc3history.org/dc3fliesitself.html. The DC-3 certainly did not have autopilot – Manuel J. Diaz Jun 24 '18 at 01:25
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    "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." I was laughing out loud for several minutes over this. Amazing. xD – Cloud Jun 25 '18 at 09:57
  • Another related incident is https://en.wikipedia.org/wiki/2002_Jalandhar_MiG-21_crash (don’t think auto pilot was involved in this one either). – Chaitanya Gupta Jun 25 '18 at 20:32
  • I can imagine a situation where a pilot would eject because the pilot could not save the jet themselves. For instance if it requires a sharp turn that would induce too many G's of force that the pilot would pass out before the manouvre is completed. It then would be nice for the plane to be able to safely land. especially in training conditions. – Whacko Jun 26 '18 at 12:05
  • If the pilot has passed out how will he or she eject? – Hanky Panky Jun 26 '18 at 12:42
  • I wonder if it would be worth considering maneuvers (especially with vector engines etc.) that would recover the airplane but kill the pilot to be done after the pilot ejected, but then how to test that... – PlasmaHH Jun 27 '18 at 08:21
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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.

tj1000
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    That’s a great answer. – Hanky Panky Jun 23 '18 at 17:10
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    +1. Ejection is not teleportation. You can get killed/maimed by the aircraft on the way out. – Nelson Jun 24 '18 at 06:07
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    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. – Thorsten S. Jun 25 '18 at 10:37
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    @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 ;) – Piskvor left the building Jun 25 '18 at 15:31
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    Self destruction sounds like an excellent idea for military planes in contested space (provided it doesn't kill the ejected pilot in the process) – rbanffy Jun 25 '18 at 17:31
  • @Nelson I read a great article about the B2 bomber. The journalist was able to fly but was not cleared by medical. In fact, at his over 6' height, if an ejection was required during the flight it would have removed his legs. So, there's that. – Wayne Werner Jun 25 '18 at 20:48
  • @WayneWerner: Ouch! How so? – Vikki Jun 26 '18 at 19:51
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    @Sean at 6'5" apparently his legs and feet might strike the console, which would be unfortunate. Here's the article (still a good read the 2nd time around) – Wayne Werner Jun 26 '18 at 21:03
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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.

Therac
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    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. – Mark Jun 22 '18 at 20:15
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    @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. – Loren Pechtel Jun 23 '18 at 04:43
  • @LorenPechtel: Well when you can land with one wing: https://theaviationist.com/2014/09/15/f-15-lands-with-one-wing/ – Joshua Jun 25 '18 at 16:16
  • @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. – Skyler Jun 25 '18 at 17:08
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    @Skyler great and now I'm imagining a situation that involves refueling a 1-winged bomber long enough to make it to Edwards. – Wayne Werner Jun 25 '18 at 20:50
  • @Joshua But note that he had to land very fast. That plane was capable of landing on the available runway despite that speed. More damage or a heavier airplane could take it beyond any available runway, or beyond what the wheels could take. – Loren Pechtel Jun 26 '18 at 17:45
  • +1 If you build into the autopilot the ability to do something special on ejection, you have to program in a whole lot of safety checks that it won't falsely detect an ejection. Much better to have it ignore the possibility, since it won't be able to do anything anyway. – DJClayworth Mar 30 '21 at 15:25
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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.

Tamás Polgár
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    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. – Pondlife Jun 24 '18 at 20:48
  • Haha that is amazing, I wonder if it ever said that in practice – Cloud Jun 25 '18 at 06:45
  • Perhaps they didn't have much faith in their ejector seat. Maybe it also dispenses a large glass of Vodka for the hapless occupant. – Wossname Jun 25 '18 at 11:00
  • Soviet/Russian seats were always very reliable, even back in the Cold War. It was really just some engineer humor at work. – Tamás Polgár Jun 25 '18 at 18:35
  • Sources are scarce on this. I heard it from a Hungarian fighter pilot who in turn heard it from a Russian. As for autopilots, sure, there are experiments, but there is no system which can reliably pilot a fighter plane, particularly not a carrier-based one. It's still science fiction. – Tamás Polgár Jun 25 '18 at 18:38
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    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. – Chris Stratton Jun 26 '18 at 05:23
  • @TamásPolgár Where have you found information that carriers do not have an autopilot? – Cloud Jun 26 '18 at 09:21
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    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? – Bob Jarvis - Слава Україні Jun 26 '18 at 14:54
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    These things are called anecdotes. Anyone looking for solid evidence to everything, go to a technical library. – Tamás Polgár Jun 27 '18 at 02:17
  • @BobJarvis Hi Bob, just did this. Can confirm story is true. – Cloud Jun 27 '18 at 06:53
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    @BobJarvis PS, how do I land this thing now?! – Cloud Jun 27 '18 at 06:53
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    @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". :-) – Bob Jarvis - Слава Україні Jun 27 '18 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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