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I know that military jets have autopilot, but do the pilots actually prefer to use it?

I ask this question because, unlike civilian airplanes, military jets are more likely to come in a situation where the pilot may have to take quick decision and leave the designated path for some mission (e.g. to intercept a civilian jet flying on a wrong path). In such case, the autopilot may become a problem for quick maneuvering.

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  • $\begingroup$ I would think they do for sure since usually it takes some time to fly to their mission zone and I highly doubt they keep their hands on the "steering wheel" all of the time. The pilots would get some kind of a transmission instructing them to divert to a different mission/path. They would have more than enough time to switch it off during the transmission or just after it. $\endgroup$ – Huangism Dec 8 '14 at 14:41
  • $\begingroup$ Also note that modern military aircraft (particularly fighter aircraft) have extremely advanced onboard computers that calculate and perform operations that civilian autopilots would be completely jealous of. While much of the 8M+ lines of code are war-fighting specific, the goal of military autopilots is to free the war-fighter of remedial tasks so they can focus on their unique mission. $\endgroup$ – Matthew Peters Dec 8 '14 at 18:57
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    $\begingroup$ The Navy has 'auto pilot' for landing on carriers at sea. Its use is optional. Apparently letting the computer land for you is stressful for some aviators. $\endgroup$ – Tony Ennis Dec 8 '14 at 22:08
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    $\begingroup$ Some military jets such as the F-15 are inherently unstable by design (this is intentional to have good maneuverability). Flight computers (independent from autopilot) are always making sure the plane doesn't go tail over nose in supersonic regime, where it's borderline impossible for a pilot to control solely manually. $\endgroup$ – shortstheory Dec 9 '14 at 7:00
  • $\begingroup$ @shortstheory, F-15 is not statically unstable. F-16 is. Besides, at supersonic they are all stable (in pitch): the aerodynamic center shifts back significantly in this regime. $\endgroup$ – Zeus Jun 25 '18 at 1:43
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I'm not in the military, so you could say I'm talking out my rear end here, but based on my experience as a pilot: yes, military pilots use the autopilot all the time.

Here's my reasoning, in order of most to least convincing evidence:

  • Punching the autopilot off takes about a fifth of a second. The button is right there on the yoke, for crying out loud. The time it takes to turn it off is not a good reason not to have it on.

  • The autopilot is a labor-saving device. When you're in an aircraft (and particularly when you're solo in one) there are times when you'd rather be paying attention to your chart or setting up the FMS or stretching or eating a candy bar instead of actually flying the plane. Also, when Air Force pilots fly long repositoning flights, the autopilot reduces fatigue between in-flight refuelings (the Navy uses carriers).

  • Times when you might have to leave the designated path for a mission happen a lot less than you think. Again, not in the military, I'm just basing this on the realities of fuel and the number of military aircraft out there. Maybe if you're flying close air support for teams on the ground or something, but remember that the military is first and foremost a logistics organization - it's a machine for moving people and things from one place to another. Most of the time, military aircraft aren't on a hair-trigger moment's notice ready-to-engage posture, they're going from one airfield to another for training or maintenance or something.

  • In most aircraft, you can override the autopilot if you need to anyway. Again, never flown a military fighter aircraft, but based on what I know about flying in general, even if you're chilling in your F-22 (with the autopilot on) if you grab the stick and yank, the airplane will move. (I would be interested to know whether this is true of Airbus aircraft. EDIT: Question answered after 4 years!)

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    $\begingroup$ As far as I'm aware it's not true for an Airbus - you have to press the over-ride thumb button to take control (and even then, you're still reined in by the "Normal/Alternate Law" systems... which sound a lot like something out of The Terminator) $\endgroup$ – Jon Story Dec 8 '14 at 17:14
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    $\begingroup$ +1 for understanding that most of the military is the "shaft" (logistics), not the "tip" (combat) of the "spear." $\endgroup$ – Smithers Dec 8 '14 at 20:46
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    $\begingroup$ I would be interested to know whether you can override autopilot by yanking the stick on F-16 and newer including F-22 actually. They are fly-by-wire, the yoke is spring-loaded with very strong springs and only moves a little (in the early F-16 it didn't move at all, only sensed force, but it felt too weird, so it was allowed to move a little) and it generally behaves much like the Airbus normal law. So it might well require pressing the override button too (which still is on the stick; fighters have almost all control on the stick and throttle). $\endgroup$ – Jan Hudec Dec 9 '14 at 8:03
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    $\begingroup$ @JanHudec 5 pounds of stick input on the super hornet will disengage the autopilot. I imagine its very similar in other aircraft like the F22. $\endgroup$ – Rhino Driver Dec 11 '14 at 7:09
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    $\begingroup$ @LRT Forty seconds?!? That's an eternity! $\endgroup$ – Steve V. Dec 11 '14 at 16:27
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Military pilots are not unlike most other pilots: we're lazy and love booze, and we become just as autopilot crippled as the next guy.

Fighter aircraft controls are designed around the HOTAS philosophy, or hands on throttle and stick. To quickly perform flight critical functions, like disengaging the autopilot, the pilot's hands do not even have to move from the controls. On the Super Hornet the preferred method to disengage the autopilot is to paddle it off with the pinky finger on the stick. However, 5 pounds of pressure on the stick will also disengage the autopilot. Furthermore, some autopilot functions of the super hornet are always on. For instance, the jet constantly trims itself to 1 G and this autotrim will relatively help maintain a stable platform.

Aside from laziness, there are times when the autopilot can be a large asset to the mission. The cockpit of a fighter aircraft can get very busy when transitioning between phases of flight.

Here are a few mission related examples off the top of my head when having some form of autopilot is really nice:

  • When leading another aircraft (it makes it easy for the wingman if you are stable)
  • When flying parade and trying to do anything besides flying parade. Flying parade sucks.
  • Configuring mission related instruments
  • Performing coupled approaches to the boat (scary)

There are as many, if not more, reasons to use the autopilot in a fighter aircraft than in our civilian counterparts. However, as you rightly assume, when we are flying dynamically (ie, low levels, BFM, bombing, etc), the AP is disengaged (save autotrim), and the pilot controls the aircraft.

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Sure, fighter pilots use autopilot quite a bit. Using an autopilot reduces fatigue on long flights and frees the pilot to navigate, manage systems, and keep a lookout for threats. Disengaging the autopilot is as simple as hitting a button in some aircraft, or just moving the stick in others - it won't slow reaction time or prevent a pilot from responding to some event.

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  • $\begingroup$ Managing systems sounds a bit funny to me in the context of military jets, yet I imagine that it can take up a large portion of pilot's uptime. $\endgroup$ – Pavel Dec 9 '14 at 10:17
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The other answers cover almost everything, but one point that hasn't been mentioned is that the auto-pilot isn't just a labor-saving device, or even a focus-saving device: it reduces human error.

Of course trained pilots, especially combat veterans, can fly extremely reliably, but humans are humans, they can make mistakes and simply engaging the auto-pilot between refueling points on the way to the mission zone and back will get rid of that possibility.

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