Affirm - NAVAIR had different specs and the jacket was made to that. The AF version is different in cut and pockets/velcro. Most of the AF folks in my office (pilots) have the OCP version and wear it with standard flight-suit. The NAVAIR version fits better I think - although in general Massif garments are cut rather generously. Both jackets are fantastic - warm and functional. I believe the CWU series jackets are dead across all the services.There’s a difference between the USAF and NAVAIR Massif jackets?