National Research Council Tailless Glider

NRC tailless glider being towed on the ground, Arnprior, Ontario, 11 June 1949.  (Library and Archives Canada Photo, MIKAN No. 3584258)

The Flying Wing or Tailless Aircraft format is a concept that was pursued from the beginning of flight, the Burgess- Dunne was one such early design.

 During the interwar period, research continued in various countries. In Britain, Geoffrey T. R. Hill, interested in designing a safer, more stable airplane constructed, with help from his wife, a working glider in 1924. His goal was an aircraft with no definite stall point and one that was resistant to spinning, making it safer to fly. The glider gained official interest and when later fitted with an engine, was shown at the Farnborough air show.

 The Westland-Hill aircraft company contracted him to build a series of tailless aircraft which they labelled Pterodactyls. In 1932 the final Mark V variant was constructed which was said to have worked as well as conventional aircraft but it was not developed further. There is a popular saying that if a plane looks right, it is right. This one could not be described as such. 

 During the Second World War, Geoffrey Hill served as the British Scientific Liaison Officer at the National Research Council (NRC) in Canada, where he proposed continuing his research. In 1946 a wooden twin-cockpit glider was built and a test program was initiated. It seems a bit strange, the Northrup Flying Wing would seem to have already advanced quite a bit further than this program.

From the Harold Skarup pages, The glider was constructed predominantly from wood with a single spar built from laminated wood supporting wooden built up ribs covered with a relatively thick plywood skin, which resulted in a smooth surface with minimal distortion.  The wing had three distinct sections, comprising a constant-chord, unswept centre section flanked by swept tapered outer sections. Primary flight controls consisted of elevons on the trailing edges of the outer wing sections for pitch and roll, with fins and rudders on the wing-tips for yaw stability and control.  Trim in pitch was achieved by adjusting the incidence of movable wing tips using screw jacks.  For approach and landing split flaps were fitted to the wing centre section trailing edge.

The undercarriage consisted of a retractable tricycle arrangement with auxiliary skids which could be lowered in case the undercarriage failed to extend. Differential brakes were fitted to the main undercarriage wheels.

The pilot and flight test engineer were accommodated in two separate cockpits protruding from the top surface of the wing centre section with the pilot in the port cockpit and test engineer in the starboard cockpit.  A comprehensive instrumentation package was fitted, with automatic recording of time, airspeed, altitude, wing tip incidence, flap angle, side-slip, roll rate, pitch rate, yaw rate, elevon hinge moment, elevon angles, rudder angles, ambient air temperature, normal acceleration (gy), longitudinal acceleration (gz), gyro attitude, pendulum attitude and bank angle.  In addition radio transmissions from the pilot and test engineer were recorded on the ground.

Flight testing of the aircraft began in 1946 at Namao, Edmonton, flown by S/L Robert Kronfeld, AFC, RAF initially and continued by S/L. E. L. Baudoux, D.S.O., D.F.C., F/L. G. S. Phripp and F/L. G. A. Lee.  Mr. T.E.Stephenson was in overall charge of the flying operations as well as scientific observations in the starboard cockpit.  Ground handling of the glider was found to be good, using the differential brakes.  Launches were carried out as aero-tows behind an RCAF Douglas Dakota with a 350 ft nylon tow-rope, at a normal towing speed of 100 mph, but tows at 140 mph were found to pose no difficulties.  Flight testing was carried out predominantly in the glide after a tow to between 6,000 ft and 10,000 ft, testing being terminated at 4,000 ft to allow positioning for entering the landing circuit.  Flight characteristics were found to be good with the exception of poor yaw control at low speeds.

In September 1948, the glider was towed 2,300 miles across Canada to Arnprior, Ontario for further testing, completing 105 hours before the project was terminated. The aircraft was stored for several years before deteriorating and being scrapped in the mid fifties.

Larry Milberry, 60 Years, CanAv books, 1984