For Testors
O-2 Skymaster 67-21331, USAF
O-2 Skymaster 67-21422, California ANG
O-2 Skymaster 68-7602, USAF
O-2 Skymaster 67-21402, USAF (Vietnam)(*)
O-2 Skymaster 67-21349, US Army
Reims-Cessna FTB337 Skymaster “13704”, Portuguese Air Force