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Hang Gliding History : Development in Britain of the Flexwing hang glider : First Generation

First Generation

The reign of the basic Rogallo in Britain began with the building by Geoff McBroom and partners of the first example during 1971. McBroom soon became a manufacturer, as did those 'early birds' who quickly followed, such as Len Gabriels, Gerry Breen, Ken Messenger and the Haynes brothers. Each of these began to apply quickly growing experience and knowledge to the task of improving what was a rather basic and inefficient flying machine. In particular the Haynes brothers, who were to form the Wasp company, were careful and meticulous experimenters. They pushed forward in the quest to produce ever better designs and more professionally finished products.

The years of the first generation glider, which spanned 1971 to approximately 1975, were a period of wild enthusiasm amongst would-be pilots and it has to be said too, a period of many accidents. A lack of knowledge of the dangers and pitfalls together with low or almost non-existent flying skills, further compounded by gliders which could only be safely flown in a narrow range of windspeeds from steep hills ensured that a high accident rate was inevitable. However progress was made and some Rogallo pilots began to actually soar hillsides rather than plummet down in a 'top to bottom' glide. McBroom was perhaps the first to post a flight duration 'record' at seven and half minutes in 1972. In truth the first generation Rogallo probably had a 3.5:1 L/D (the angle at which the glider descends through still air ) which meant that only a few hills were suitably steep and obstruction free to provide a chance of soaring flight. Two of the most suitable and therefore well frequented were Hay Bluff and Rhosilli. This last in particular was to see many attempts to establish a record endurance flight. Whilst in 1973 the longest flights were little more than one hour, by early 1974 it was over two hours and from then on flights of ever longer duration were recorded almost weekly until the record was abandoned as no longer of any significance for upon the introduction of improvements to glider performance the only governing factor to flight duration was pilot fatigue.

The first generation Rogallo hang glider was of a conical design; i.e. each wing of the sail formed a part cone. The early machines were at first without a kingpost, which was universally accepted in 1974. Before its adoption ground handling of the Rogallo had been sloppy due to excessive flex of the frame. However another and more important reason for the adoption of the kingpost and upper rigging was that it retained reflex in the keel boom. The importance of reflex as an auto-stabilising mechanism in tailless aircraft was well understood. Briefly, the reflex, or raising of the trailing edge of the wing ensured that in a dive aerodynamic forces would try to return the wing to trim speed flight. Therefore it was imperative, or otherwise the glider might enter at high speed an ever increasing and uncontrollable dive. This was referred to as the 'luffing dive'. The luffing dive was a bogey then, perhaps comparable with the fear of spinning felt by the pilots of powered aircraft in the early years of the last century, therefore carefully avoided by most pilots. Less inhibited types, who had cracked the challenge of soaring, delighted in performing hammerhead stalls which naturally sometimes preceded an exciting and usually fatal plunge. In May of 1975 Geoff McBroom published details of an anti-luffing system which in essence was the application of lufflines from the kingpost to points near the trailing edge of the sail of a standard Rogallo. Only later was this idea taken up.

General Specification of first generation gliders

Aspect ratio 2.5-3.75.

Nose angle 80-90 degrees.

Sail planform Delta. No roach on trailing edge with a slight hollow cut and pronounced tail.

Sail shaping Normally flat cut but occasionally external camber cut in as a dog-leg to counter leading edge flex.

Keel and leading edges Normally same length.

Cross tubes Exposed and mostly one-piece.

Sail slackness 3.5-5.0 degrees billow.

Top rigging Early versions had no top rigging.

Battens None almost exclusively.

Pitch stability From keel reflex only.

Duration of type 1963 to 1975.

Examples All standard Rogallos including, Wasp 229, Hiway (220 240 260), Breen CustomKite, Skyhook 3, Birdman Grasshopper and Hawk, McBroom Arion.

First Generation
Hang Gliding History : Development in Britain of the Flexwing hang glider : First Generation