TYPE: Ornithopter.

PROGRAMME: Early research resulted 1985 in quarter-scale, hand-launched, engine-powered and radio-controlled flying model; this progressively improved into more efficient model flown 4 September 1991 and recognised by FAI as first successful engine-powered ornithopter. Feasibility study 1993-94 for full-scale prototype, construction of which began 1995; this aircraft (C-GPTR) began taxi tests October 1996 and by 1999 had demonstrated ability to accelerate under own power to more than 43 kt (80 km/h; 50 mph) and make a number of brief hops. Further activity suspended in third quarter 2001 pending additional funding and apparently unchanged by mid-2003. In addition to Toronto University, Project Ornithopter currently has some 16 sponsors including Canadian National Research Council, the Ken Molson Foundation and Toronto Aerospace Museum. Criterion for success is considered to be sustained flight of at least 11 seconds.

COSTS: Development costs of full-size prototype £140,000 up to mid-2001.

DESIGN FEATURES: Conventional fuselage and tail unit. Flapping wings are hinged to a centre-section which is moved up and down by pylons connected to the drive train and pivot on the ends of vertical struts mounted on short outriggers attached to the base of the fuselage. Thus, when centre-section pushes up, wings flap down, and vice versa. Wings deflect 53° 36' up and down, and are designed to flap 1.3 times per second.

FLYING CONTROLS: All of thrust and most of lift created by mechanical flapping of wings. Thrust due mainly to low-pressure region around wing leading-edges, which creates suction. Wings also able to twist passively ('aeroelastic tailoring') to prevent airflow separation at trailing-edges. Rudder provides control in roll as well as yaw, due to wing opposite direction of yaw gaining lift while that of other wing loses lift.

STRUCTURE: Fuselage frame of aluminium tube; wings of Kevlar, carbon fibre and epoxy resin; Dacron overall covering.

LANDING GEAR: Tricycle type, fixed, with cantilever, self-sprung mainwheel bows; shock-absorption on nosewheel leg. Gear designed to give aircraft a nose-down attitude on ground, to minimise bounce during take-off run.

POWER PLANT: One 17.9 kW (24 hp) König three-cylinder, two-stroke, fan-cooled engine, with 60:1 reduction gear drive to power wing centre-section. As latter requires more power on downstrokes than on upstrokes, engine stores energy on flywheel between downstrokes.