U.S. military aviation officials are ordering versions of 58 V-22 tiltrotor aircraft and avionics from the Bell-Boeing Joint Project Office (JPO) in St. Louis under terms of a $4.2 billion order last month. Officials of the U.S. Naval Air Systems Command at Patuxent River Naval Air Station, Md., are asking the Bell-Boeing JPO to build 39 CMV-22B aircraft for the Navy; 14 MV-22B aircraft for the Marine Corps; 1 CV-22B for the Air Force; and 4 MV-22B aircraft for the government of Japan. The Bell-Boeing JPO is a joint venture of Bell Helicopter in Fort Worth, Texas, and the Boeing Co. Defense, Space & Security segment in St. Louis. The V-22 Osprey uses tiltrotor technology to combine the vertical performance of a helicopter with the speed and range of a fixed-wing aircraft. It features vertical take-off and landing (VTOL) and short take-off and landing (STOL) capabilities, and is designed long-range high-speed missions.