Helicopter Bell OH-13S Sioux Serial 4011 Register ES721 used by Elliniki Aeroporia Stratou HAA (Hellenic Army Aviation). Aircraft history and location Aircraft History ES721 Elliniki Aeroporia Stratou 1971-05-10Hellenic Army FMS 69-19631 d/d 10may71 Send Updates Use APP to upload photo @ (optional) When Now? / / Send