reported Rapid drift of Attitude Indicator

[BIGNEWY]

threads merged

[Bucic]

I replicated my winter instant action Take Off 1 mission flight and got similar results still. I'll submit a short track tomorrow. This one was over an hour long.

[NineLine]

47 minutes ago, Bucic said:

I replicated my winter instant action Take Off 1 mission flight and got similar results still. I'll submit a short track tomorrow. This one was over an hour long.

I appreciate it, will check where we are on this once you submit a new track. Thanks!

[Bucic]

14 hours ago, NineLine said:

I appreciate it, will check where we are on this once you submit a new track. Thanks!

Done.

This time around I concentrated on doing a shorter stint to make the ADI did something weird and I sure managed to. It flipps in a way I haven't seen in the legacy module. But no drift was present during the flight.

Next I'll try to record a track of anctual Upgrade ADI drift, as I witnessed yesterday.

 

Flight profile:

Instant Action take off 1

flat wide turns and split S with initial climb, then level

Youtube video uploading to confirm we're seeing the same flips. The video starts right after I saw the first flip to make it occur again. It did.

https://youtu.be/JaQuUKjggsE

 

In the legacy version it was enough for me to turn 90 deg on the ground to taxiway to induce a significant change in drift (see my previous youtube upload). As you can see, this time it was not the case. I even caused the 5 to make a 180 deg rapid twister skid. No ADI drift observed.

bug F-5E UPG ADI still 01 2024-12-05.trk

Edited December 5, 2024 by Bucic

[Bucic]

Notably the backup ADI did not follow the main ADI in the flipping process

 

 

[Bucic]

OK, drift replicated. It seems that it can be triggered on command, e.g. an ADI drift to the right can be triggered by a wide right turn. As you can see in my afternoon test flight I follow by "pushing the drift" to the left by a wide left turn.

I triggered the bug in 10 minutes and that includes the takeoff and climb.

What seems to be the problem is while there is an internal mechanism facilitating ........................... self-centering when in unaccelerated straight and level flight the threshold values used for detection of the conditions for self-centering are incorrect (too wide) so the ADI tries to level itself in shallow turns. This would explain the possibility to "reverse the drift" directly following a drift accurence.

OK, at this point I'm going to need further pointers as to what type of tracks to gather. I'm out of ideas for now.

https://youtu.be/Nrb2TNouzEE

 

Track: please disregard the second half of the track after 11th minute mark.

bug F-5E UPG ADI still 02 2024-12-05 replicated.trk

Edited December 5, 2024 by Bucic