
If a pilot ejects, what is the autopilot programmed to do? - networked
https://aviation.stackexchange.com/questions/52862/if-a-pilot-ejects-what-is-the-autopilot-programmed-to-do
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mabbo
I'm annoyed that the top answer is basically saying "well that wouldn't
happen". So what? The question wasn't about how likely a thing is, it's what
happens should it occur.

It would be like if someone asked "what would happen if a C program tried to
access uninitiated memory?" And the answer was "Good programmers would never
do that".

~~~
everdev
My kids ask questions like this all the time.

Them: What if a shark jumped into a volcano?

Me: That wouldn't happen because sharks live in the ocean and can't jump high
enough or far enough to reach land.

Them: OK, but what if?

Me: ... It would get burned and die...

So yes, if a pilot ejects and the plane had auto-pilot on and the auto-pilot
was programmed to try to land after a pilot ejection and the plane was still
safe to fly, the plane would in fact attempt to land.

~~~
dotancohen
A few decades ago an F86 pilot ejected from a flat spin. The resulting
changing in CG leveled off the aircraft and when his wingman saw the plane
flying level and straight again, he radioed "You better get back in that
plane". It landed in flyable condition in a corn field, engine running.

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theoh
This is a similar story. (Maybe it is actually the incident to which you are
referring?)

[https://en.wikipedia.org/wiki/Cornfield_Bomber](https://en.wikipedia.org/wiki/Cornfield_Bomber)

~~~
dotancohen
Thanks, that's the one! It was an F-106, not F-86.

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Ylodi
After The Pilot Ejected, This F-106A Flew for Miles Before Landing Gently in a
Field! [https://www.warhistoryonline.com/history/plane-flew-pilot-
ej...](https://www.warhistoryonline.com/history/plane-flew-pilot-
ejected-f-106a-flew-miles-landing-gently-field.html)

~~~
JshWright
That wasn't the autopilot though, that was just aerodynamics.

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samlittlewood
Somtimes, you don't even need an autopilot:

[http://www.ejectorseats.co.uk/ejection_from_a_harrier.htm](http://www.ejectorseats.co.uk/ejection_from_a_harrier.htm)

~~~
knodi123
fantastic, i love anecdotes like these.

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sandworm101
Take this from someone in an actual air force: (On lunch break atm by I am
wearing a flight suit.)

(1) The chance that the 'autopilot' will even be on in an ejection scenario is
very low. If something does go wrong, pilots will take control first, eject
second. Disconnecting the autopilot will happen either deliberately or
automatically as the pilot moves the stick.

(2) Aircraft with ejection seats are not Cessnas. The "autopilot" might not be
on, but the fly by wire control system is never really off. That system will
remain active and could potentially "fly" the plane some distance. Think of it
like a car sliding on ice. The cruise control might be off, but the stability
assist system isn't. The driver can jump out and the car still recover itself.

(3) The engine(s) will keep going. Ejection does not turn off anything. It's
not like falling off a jetski where a kill switch is pulled. The throttle will
be wherever the pilot left it.

There have been a handful of incidents where a pilot has ejected and the
aircraft continued on without him/her. I've read about this with test pilots
in spins. The aircraft is spinning and unrecoverable, so the pilot ejects. The
aircraft then self-recovers through a combination of inherent aerodynamic
changes (falling into thicker air) and/or efforts by the fly by wire system to
maintain the commanded heading/pitch from a now-unmanned stick.

There is an adage amongst fighter pilots that they shall not punch out until
they know where their aircraft will land. Hanging in a parachute as your
aircraft recovers and continues strait into a school. If over land/people they
will stay with it until VERY close to the ground.

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cbr
[https://en.wikipedia.org/wiki/Cornfield_Bomber](https://en.wikipedia.org/wiki/Cornfield_Bomber)

[https://en.wikipedia.org/wiki/1989_Belgian_MiG-23_crash](https://en.wikipedia.org/wiki/1989_Belgian_MiG-23_crash)

~~~
huhtenberg
Re: Mig-23 incident - at the time of the incident it was a popular theory that
this was Soviet's answer to Mathias Rust landing his Cessna on Red Square two
years prior.

[https://en.wikipedia.org/wiki/Mathias_Rust](https://en.wikipedia.org/wiki/Mathias_Rust)

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BuildTheRobots
I thought with military craft, as soon as the ejector handle is pulled the
onboard computers are wiped/destroyed before the seat even exits the aircraft.

~~~
derefr
Even moreso, I would expect that with most experimental or non-commodity
military craft in actual combat situations (i.e. the kinds you really don't
want the enemy analyzing or using against you), the plane would just explode
as soon as you're a safe distance away.

Like scuttling a ship, but smaller.

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rurban
I can answer a similar question in Formula 1 engine testing failure. It might
be similar to the plane problem.

There are basically two options: Hard shutdown (power off, full brakes) vs
Soft shutdown (power off, doing nothing). Both have it's merits and usecase,
and are selected by the SW automatically. HS could save lives but could be
very expensive, as the engine could be broken by the strong forces. SS could
last a few minutes and destroy the engine also.

In the plane cases you don't have that many options there, though usually with
4 more degrees of freedom yodur options on a plane are much higher. I don't
think that there are programmed sequences, but with military applications I
would be not surprised to see both options implemented. Escape as far as
possible vs hard vertical acceleration for maximal destruction.

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zimbatm
Once the pilot is ejected, the autopilot doesn't need to concern himself with
human G limitations. That could be useful for drastic recovery maneuvers.

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yardie
Considering that a rocket was just lit in an enclosed area, how much of the
autopilot is left to be functional anyway?

~~~
ceejayoz
I suspect it's fine. Two-seater planes fire the seats in sequence - if it's
not frying the other passenger, it's highly unlikely to be melting the
instruments.

[https://upload.wikimedia.org/wikipedia/commons/9/9c/Ejection...](https://upload.wikimedia.org/wikipedia/commons/9/9c/Ejection_seat_test_at_China_Lake_with_F-4B_cockpit_1967.jpg)

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tabtab
Per military planes, I suspect they select the preferred behavior ahead of
time based on the mission and estimated flight path. In some cases self-
destruct may be the better option, in others, a controlled landing is better.
You probably don't want to self-destruct over your own cities and thus build
in logic to find a rural landing spot if it's a local or training mission.

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gnode
I would object to the premise of the question:

> I would want to build in a way for the plane to try and save itself if
> possible

In a combat situation, I would imagine you'd want to destroy the aircraft if
you lost control of it, to prevent the enemy recovering: the working aircraft
itself, the technology it contains, or any sensitive reconnaissance recorded
on it.

~~~
kejaed
As someone who has worked on the F/A-18 (actually CF-18) mission computer
software, when the pilot ejects the mission computers start to erase the
sensitive information that they contain.

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chaitanya
This reminded me of a tragic incident from my hometown a few years back
(though I don’t think autopilot was involved):
[https://en.wikipedia.org/wiki/2002_Jalandhar_MiG-21_crash](https://en.wikipedia.org/wiki/2002_Jalandhar_MiG-21_crash)

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artur_roszczyk
[https://www.warhistoryonline.com/history/plane-flew-pilot-
ej...](https://www.warhistoryonline.com/history/plane-flew-pilot-
ejected-f-106a-flew-miles-landing-gently-field.html)

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mongol
I think it is programmed to control the plane. Not to autoland it, but to keep
it flying. When JAS Gripen crashed in Stockholm after instability, the pilot
ejected and the plane managed to improve its stability somewhat before
crashing.

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rconti
TL;DR: "It's not"

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pbhjpbhj
Which isn't an answer to the question.

"The autopilot doesn't change its operational parameters to account for
ejection." would be an answer, meaning it takes no account of it and continues
as before.

Saying "it's programmed to do nothing" is very different: meaning it would
stop, meaning it would be taking notice of the ejection.

~~~
rtkwe
The real answer is more along the lines of 'if the pilot has ejected there's
some serious issue with the plane and the autopilot has been disengaged in
attempts to rectify the problem, either automatically in the case of a stall
or spin or by the pilot giving inputs which would disengage the autopilot.'
There's no instructions after that because the plane is assumed lost once the
pilot ejects.

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Shivetya
It likely isn't active because any event which causes loss of control of the
aircraft will exceed the autopilots limits.

As for crashed military, state side decades ago I did a shoulder to extended
arm walk in the wood. Overseas a sister squadron deployed some guys to recover
what they could and destroy the rest; that was in a "not so hostile" country.

~~~
Someone1234
The autopilots flight envelope limits are somewhat artificial though. If you
wanted to, you could design it to try and take over no-matter-what in the
event of an ejection.

The biggest question I'd have is: What would you even want the auto-pilot to
try and do after an ejection? Assuming it somehow gained full flight control,
then what?

~~~
pbhjpbhj
You might eject when in control of the vehicle if it couldn't land, or there
was an engine fire say. You probably want the vehicle to ditch where it will
do least harm.

~~~
ceejayoz
> You probably want the vehicle to ditch where it will do least harm.

Not if it's a military aircraft with classified equipment over enemy
territory.

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Crespyl
In that case, "least harm" might mean "find the least accessible location and
crash in whatever manner does the most damage to sensitive components",
assuming "go to nearest allied country and crash-land" isn't an option.

~~~
rtkwe
This falls along the same lines to me as the "autonomous car morale quandary"
questions that were really popular for a while. Both assume the situation is
bad enough that the pilot has ejected/car can't avoid the accident but the
airplane/car has the control authority left to actually make the choice.

~~~
Crespyl
Right, as the commenters in SO point out, any situation that's bad enough for
the human pilot to eject is also almost certainly bad enough that the
autopilot won't be able to do much.

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drivingmenuts
Favorite answer:
[https://aviation.stackexchange.com/a/52931](https://aviation.stackexchange.com/a/52931)

Clippy's flying the plane, folks.

