Doofa (oz3253)

About this Plan

Doofa. Glider model. The design dates back to 1947, but appears here in a later 'nostalgia' article from 1989.

Quote: "This'll Doofa now! Try Dave Hughes' three-foot lightweight glider for Vintage fun.

DOOFA is a lightweight tow-launch glider, of low aspect-ratio, designed primarily for those all-but-calm summer evenings which seemed to abound in the late 1940s. It weighed just 2-1/2 ounces and utilised the special LDC 2 section, produced by the LSARA (Low Speed Aerodynamics Research Association) mentioned recently in the Readers' Letters page.

Well, something like that section, anyway, as I cannot recall having used any ordinates, so it was probably 'eyeballed' - and, in 1947, no doubt distorted via the 'pin-prick through onto balsa' technique. But it certainly seemed to work well - and still does!

Years later I was told by some technical type that the LDC 2 section only works for streamlined fuselages. I spent the next few weekends trying to get my Doofa VII to fall out of the air, once this knowledge had been imparted. But it would not.

Drawn, built and flown one Saturday in June, the model seemed promising from the start - though admittedly, the 'flown' part that Saturday was just a hand-launch from the sand-dunes bordering the Royal Liverpool golf course at Hoylake, in the gathering dusk.

For later, tow-launched flights, we moved onto the beach at West Kirby, which afforded something like three square miles of flat firm sand, when the tide was out. The only problem for most of us was that wingtips became 'sandpapered'. Doofa had to go one better than this, however, and wandered away, to land a few inches from the incoming tide. By the time we reached it, the tissue had become very soggy, the model having been trying to emulate a surfboard.

About this time, the Merseyside club obtained the use of RAF Sealand (near Chester) and during the next couple of years I managed to lose three Doofas OOS and burn a fourth. Yes, I said burn. It sat on its own D/T fuse. In view of losing the other models I decided to fit one of these, you see. But not your conventional tip-up tail arrangement. I thought I'd try the swinging-weight type which I suppose I must have seen in Gadget Review.

The system required a small weight to be secured beneath the fuselage, at the CG, by an elastic band, through which the fuse was fitted. From the weight, a length of cotton ran to the wingtip. When the fuse burned through the band; presto! - the weight swung from the wingtip and the model gently spiralled downward..."

Supplementary file notes

Planfile includes article.

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