The rank insignia is a Staff Sergeant so I'm guessing a door gunner or similar. Probably not a crew chief since they have no wings. Since you are Army I'd assume you know more about uniform insignia than I do for the Army.
I don't like the 2 piece flight uniform. Just MHO.
The no wings thing is because there are no leather patches allowed on the A2CUs and pin on wings are a FOD hazzard, so in effect no one wears their wings on A2CUs. I was just generally complaining about A2CUs.