Globemaster C17 Last Update Problems

After this last update, I’m having BIG issues with the C17.
I have try several different things to figure out how to solve the problem and no luck.
Auto Pilot Problem - Safe altitude for C17 now is Maximum 26,000 ft. - 27,000 ft.
Maximum Speed is 280 - 300
Anything more above those parameters puts the C17 in unstable stage (screen starts to jump up and down) causing Auto Pilot to disengage and go out of control falling down and picking up speed VIO’s on the way down before the crash.

For past several years, I have paid the sub to be able to enjoy flying the C17, even tho it has been neglected by InfiniteFlight dev team, still I was able to make this bird work and fly with its prior specs…

This issue of C17 happens only when auto pilot is engaged, if you turn off the auto pilot, plane stabilizes instantly and you can speed up or climb higher for as long as you stay with manual controls.

Really looking for some solution to this problem, and if anyone can help or direct me on who to talk to about this issue, I would be very thankful for it.

Device: iPad Pro
Operating system: iPadOS 17


Hey brother hope all is well. Just to possibly narrow this down, are you utilizing trim and flaps for ascent profiles? Or is it purely auto pilot engagement at operating altitudes?

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Hi Andrew, yes I did play around with trim, and got that figured out during manual flight. I have try same during a flight with auto pilot on and it does not help at all. It looks like C17 is limited and under different secs when you engage the auto pilot.
Really disappointing … I understand that I may want to fly slow and low, but if I need to be able to climb above 26,000 ft and speed up to M.085, I should be able to do so with no problem as I did before the update.
Again, maybe someone knows what I don’t know, but for sur I have spend a lot of time to try everything I could, reading about the trim and other controls.

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Got it! Hang tight brother I think I suspect what is happening something similar to what is going on with F/18 AP from what I’ve been reading. Can’t promise anything quick on a resolve but may find a tool or two to continue to make her airworthy.

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I have also noticed the same issues with the F-18 as well, it will jerk drastically where at some point will disengage the A/P

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I know for certain this one is being looked into by higher powers than I and it also may solve the issue above as well. I also think I’m going to run the A-10 and F-16 to see if they also experience the same issue.

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Not from any TO but an open source unclass find to try out with C-17.


I’ve had this issue as well with the C-17 in the new update. The autopilot starts over-compensating and goes into an up-and-down pitch “loop.” The performance of the aircraft in general felt really low when trying to reach a normal cruise altitude, even while light.

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Thank you Andrew 🙏🏻
I will definitely play around with this info and see how things workout.


Sounds like the MAX IRL. Except in this case, it took real people’s lives. 😔

From what I found in a check flight it is safe to climb higher, FL320 was my test attempt.
With AP on you need to make sure not to exceed N1 100%, meaning you can’t set speed before reaching cruise attitude.
With AP on you need to keep trim in the green, not by trimming itself, but by adjusting climbrate, and flaps.
Climb rates acourding to the previously shown public sheet were fine in IF.
Speed’s need to be higher in IF then those numbers below FL100 to prevent a stall, but that’s not new.
My findings so far, my load was 83% (max fuel no cargo takeoff)

Cruise attitude was never up to real numbers, FL350 was the max flyable as far as I remember.
TAS seams not to fit MACH, might be the root cause, who knows.

Keep an eye on N1 and Trim Information is the best we can do for the moment. Beside raising the wish for a rework again and again.

Unfortunately the legacy aircrafts will get more and more difficult each time the IF environment were tuned more realistic. It would be a shame to loose this beauty by that, a rework would be fantastic and is desperately needed.


Yes, I have try parameters what Andrew posted above regarding C17 and I have try to play around with all the info you stated in your post, but still same issue.
At 26,000 ft. - 27,000 ft around 280 - 290 speed, all is ok. You try to step above this altitude or increase the speed and auto pilot gets unstable and will disengage …
Without auto pilot, C17 is stable which is great for short local flights, but not long distance cargo transfer, unless you stick around with criteria listed above.
Anyway, thank you all for all the hints and help on this one.

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