The air force includes the 449th Helicopter Gunship Squadron (449 ΜΑΕ) – operating Aérospatiale SA-342L and Bell 206 and the 450th Helicopter Gunship Squadron (450 ME/P) – operating Mi-35P helicopters and the Britten-Norman BN-2B and Pilatus PC-9 fixed-wing aircraft. Current senior officers include Supreme Commander, Cypriot National Guard, Lt. General Stylianos Nasis, and Chief of Staff, Cypriot National Guard: Maj. General Michalis Flerianos.[citation needed] The Evangelos Florakis Naval Base explosion, which occurred on 11 July 2011, was the most deadly military accident ever recorded in Cyprus.