From Wikipedia the Arms of the 633rd Airbase Wing Host Organisation of the Joint Base Langley-Eustis, VA. This is the Former Langley AFB united with the Army’s Fort Eustis.

http://upload.wikimedia.org/wikipedia/commons/thumb/3/37/633d_Air_Base_Wing.PNG/200px-633d_Air_Base_Wing.PNG

Quite good for a USAF Shield, clear symbolism of the fighters (F-22 Raptors at present) the 633rd ABW supports.