Precedent for Characters who are Mechwarriors AND Aerospace Pilots

[guardiandashi]

cross trained by default
special forces such as death commandos and other nations equivalents.
all LAM pilots ... except the jade falcon ones

now I would tend to figure that cross trained and special forces are going to be at least 1 rank less on their cross trained skills than a specialist

[Hellraiser]

Even so I believe it wasn't actual Aerospace Pilot training but rather how to deal with attacking Aerospace Fighters as a MechWarrior.

Agreed.  That was how to understand & deal w/ fighters, not Be a fighter pilot.