[REPORTED]Low altitude, Low fuel, High speed wobbling - ED Forums
 


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Old 04-11-2020, 03:38 PM   #1
Quetzalkoatl
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Post [REPORTED]Low altitude, Low fuel, High speed wobbling

Hey,
I have found a bug in F-16.

While being low on fuel <2000lbs, and relatively low alt <3000 ft, and flying above Mach 1 speed plane starts to wobble. It's impossible to counter it.

To be honest, moving any surface during this event or when it is about to start wobbling will cause much stronger wobble later.

I've tried it only with no pylons loadout.

Problem doesn't happen when plane has more than 2000lbs fuel.

There are 2 short tracks, in 2nd one I have turned autopilot on (alt and course hold).

F-16C_low_alt_FBW_bug .trk

F-16C_low_alt_autopiloton_FBW_bug .trk
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Old 04-11-2020, 03:56 PM   #2
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Reported for investigation.

thanks
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Old 04-11-2020, 06:28 PM   #3
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Just an update

Maximum operating airspeed is 800 knots from sea level to 30,000 feet MSL. Above 30,000 feet MSL, the aircraft is limited to 2.025 mach.

The team will investigate behaviour outside of the allowed envelope. When I know more I will pass it on.

Thanks
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Old 04-12-2020, 01:37 AM   #4
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For info, it is an engine limitation not an air-frame limitation.
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Old 04-24-2020, 01:21 PM   #5
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Default F16C low level high speed

Is this a bug or something like that happen in the real F16C at low level - high speed ??

https://gofile.io/?c=HwYdKr

The aircraft starts to shake like hell
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Old 04-24-2020, 01:47 PM   #6
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https://forums.eagle.ru/showthread.php?t=269358

Reported
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Old 04-24-2020, 01:52 PM   #7
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threads merged

thanks
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Old 04-24-2020, 01:55 PM   #8
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Thank you
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Old 04-24-2020, 02:53 PM   #9
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I had this happen to me as well, shortly after I bought the Viper. I created a mission where it was clean wing, and full fuel. Quite a lot of fun when you start the takeoff roll and hear the burner kick in!

Anyway, I went low level, about 150 feet over water on full burner with the altitude hold turned on. Don't recall my fuel state, but it was not bingo. As I went faster I started to oscillate side to side as well, which got progressively worse. I pulled back the throttle, but was still oscillating badly. Got to the point that it blacked out my pilot, and when he came to, I was inverted but stable and still flying.

I didn't save that track, but I'll see if I can duplicate it.
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Old 04-24-2020, 03:21 PM   #10
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Just tried it again, and I was able to induce the wild oscillation repeatedly at various fuel states. Above 800 KIAS, kicking the rudder will set in motion the oscillations.

I have been unable to correct it with normal control inputs. My only reliable way out of it is to throttle back and put the speed brakes out. The oscillation starts to dampen out, and the aircraft recovers around 500 KIAS.

EDIT: I did try one where I went low level and full burner, setting the altitude hold and no control inputs. Got just above 900 KIAS and it stayed straight as an arrow the whole time.
Attached Files
File Type: trk f-16 oscillation.trk (62.8 KB, 13 views)
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Last edited by Diesel_Thunder; 04-24-2020 at 03:25 PM.
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