I was unfortunately unable to reproduce the issue. Could you please try and switch to steam dev and try reproducing the issue there? THank you!

I was able to reproduce it in EXE rev. 131644. I entered into Huron and Ghost Hawk as a pilot, while i looking down. https://www.youtube.com/watch?v=PdjRLgEYg3Q

I have a TrackIR 5 with software TrackIR version 5.2.200 (Build 14548)

Just tried this on the steam Dev build and the issue was still live. Shall try and talk to some other TrackIR users and see if they have the same issue.

It may be useful to compare TrackIR versions, drivers, software and configuration (as danczer already provided).

I am also running version 5.2.200 and the latest arma version on steam.

This issue started since the latest Arma patch (previous to the hotfix)

This issue is not present in the 1.46 legacy. In 1.46 the character looking forward during the get in animation that's why it isn't happen. Check the video: https://www.youtube.com/watch?v=43ZVYxL9szk

The issue is exist, because we are able to turn our head while entering(during the animation) into the vehicle.

Btw I don't know why you can't reproduce it.

I found this in 1.48 changelog:
Tweaked: Moderate overhaul of freelook, ‘Numpad’ looking and head-tracking behavior (more adjustments in the near future, depending on feedback)

Maybe because of this can we look around while get in animation is played.

I'm using an older TIR version with up to date drivers. The issue is still present. Its a bug introduced by 1.48 and I know many guys who are experience it every time. Started to pause TIR while getting in...

Please revert or fix this "overhaul", whatever it is. I didnt notice any "improvements", what does it change exactly?

yup
reproducible here
Using right now TrackIR Version 5.2.200 (Build 14548)

can deliver DXDiag if needed (+ the fancy other stuff you guys would need for it)
because this shit is really annoying (at least i finally know what causes it ...)

The issue has been successfully reproduced and is awaiting fix

Hurray! Is there any chance to push it in the 1.50?

EXE rev. 131862 (game)
Fixed: Bugged view whilst using TrackIR and entering vehicles

I can confirm that it has been fixed.

Thank you Adam.

Any chance you could give us an Update on:
"#0024027: Re mapping controls binds Joystick and key"
Since May no update only that its not occur on a Logitech 3d Extreme. But the issue occurs on other devices like MFG Crosswind, Thrustmaster, Saytek etc.

Thank you.

Just a thank you for attending to this issue in such a speedy manner!