[1] The tandem seat Harbinger was designed jointly by Waclaw Czerwiński, who had already developed several gliders in Poland before World War II,[2] and Canadian Beverley Shenstone, who had worked in Germany on the Junkers Ju 52 then later, in the UK, on the Spitfire.
On each side another pair of horizontal braces ran from the rear root connection to a point on the spar at the inner-outer panel junction.
A central landing skid ran from the nose to below the bottom of the lift strut where there was a single, part exposed, fixed wheel.
The UK aircraft was built at Camphill, Great Hucklow, the home of the Derbyshire and Lancashire Gliding Club by Fred Coleman and was not completed until the Summer of 1957, when it was discovered that as designed the cg was too far aft.
Construction of the Canadian aircraft was not so far advanced in 1957 and its builders chose to retain the original design fuselage but add slight rearward sweep to the outer wing leading edge, moving the center of pressure backwards.
[2] The UK Harbinger returned to Camphill after its early tests and flew there until damaged in an aerial collision in June 1959.
Returned to flight in 1962 with a more rounded canopy closer to the original design, it was the highest ranked two seater at The Northern Glider Competition held at Doncaster in July 1965.
[2] The Canadian Harbinger made some thirty fights with the Gatineau Gliding Club, based at Pendleton Airport near Ottawa, between 1975 and 1977 before being retired.