Acquisition, design modification, assembly, and ground test of NPS Hummingbird remotely piloted helicopter

Abstract

The Hummingbird is a 15()-lb. gross weight, remotely piloted helicopter (RPH) with a 50-lb. payload and a rotor radius of 10.25 ft. It is powered by a 25 h.p. air cooled two-cylinder Westlake engine. As such it represents one of the largest RPH's in the world. It was purchased from Gorham Model Products in 1992 to provide a suitable rotor craft research flight test platform for the Department of Aeronautics and Astronautics at the Naval Postgraduate School. The helicopter was delivered disassembled and was accompanied by an ample supply of replacement and spare parts. Also included was a second helicopter in a partially assembled condition that had been previously flown. Assemblies provided comprised the chassis, main rotor transmission, rotor head assembly and tailboom with tail rotor gear box and rotor. The task undertaken by this thesis was to fabricate one complete fully operable RPH and to design, fabricate and install whatever new assemblies that were required for its NPS mission and to make up for deficiencies in the previous design. The work completed required: (1) Design, fabrication and installation of a new skid-type landing gear system; (2) Redesign, and incorporation of a new engine mount system; (3) Modification of the engine and main rotor transmission coupling; (4) Upgrade of the electrical system and elongation of the nose section; and (5) Initial engine testing. Recommendations for future modifications to the helicopter and laboratory facilities, and development of a static hover test fixture are also included