... yep, this happens when the Head is misplaced in the hier.him file, the Attaching values of the Head msh file are wrong ...
Example :
[Pilot1_D0]
Mesh Pilot1_D0
Parent CF_D0
Attaching 1 0 0 0 0.12187 -0.992547 0 0.992547 0.12187 0 -0.209591 -0.386555
CollisionObject xpilot1a
CollisionObject xpilot1b
[Head1_D0]
Mesh Head1_D0
Parent Pilot1_D0
Attaching 0 -1 0 0 0 -1 1 0 0 0 0.0122687 0.619208 <== these values are wrong in your example[HMask1_D0]
Mesh HMask1_D0
Parent Head1_D0
Attaching 1 0 0 0 1 0 0 0 1 0 0 0
[Pilot1_D1]
Mesh Pilot1_D1
Parent Pilot1_D0
Hidden
Attaching 1 0 0 0 1 0 0 0 1 0 0 0
... where did you find the Hawk 75a-3 with new pilots, as it is not in this topic ...?
Here is what you can do yourself to fix this issue ...
First, and as usual, Back Up the faulty Hawk folder ...
1) Open the Hier.him file of any Hawk that works for you (without the head problem)
2) Scroll down to the [Head1_D0] line, and copy the Attaching line (right click etc ...)
3) Open the faulty Hawk Hier.him and scroll down to the [Head1_D0] line and replace the Attaching line with the one you just copied ...