The story of the test flights of the alula wing and the projects proposed by Booth have been covered in this thread already. Among the various characteristics of the wing that enable efficient flights, the alula, a small group of feathers that are attached to the leading edge of the wing, is known to enhance lift. I would think that Handley-Page’s lawyers would have had a close look at this patent as it is very similar to their slot system in some aspects. Bird wings are complex devices that are highly specialized in generating forces necessary for flight. Where Varioplane could appoint three directors and Blackburn two, which probably gives an indication of the split in funding.Ī revised patent for the alula wing was then granted in 1921 this featured a more refined version of the auxiliary aerofoil. It was a co-venture between Holle, The Varioplane Co Ltd and Blackburn Aeroplane and Motor Co Ltd. This was the Commercial Aircraft Wing Syndicate Ltd, with capital of £30000 in £1 shares. In 1919 a new company was formed to build and test an alula wing and exploit the potential. The aim was to manage the flow of air over the wing’s surface through the application of wash-out and taper and to eliminate the need for drag-inducing ailerons by altering the air-flow and lift over the wing by the use of auxiliary aerofoils on the leading edge. For the and wings, a precipitous loss in control power follows lift stall as expected for a control surface placed at the trailing-edge of a stalled wing. The patent for what became known as the alula wing, named after the small feathers on the leading edge of some birds wings, was applied for in 1918. The Syndicate also held patents in association with others applied for during the war years. The word is Latin and means 'winglet' it is the diminutive of ala, meaning 'wing'. Capital was £16000 in £500 shares, directors Holle, G.J.L.Nicholson and G.P.M Van Weel. The alula / ljl /, or bastard wing, (plural alulae) is a small projection on the anterior edge of the wing of modern birds and a few non-avian dinosaurs. Ltd in September 1913 to acquire the rights to his patents. He became a resident in Britain sometime prior to WW1

The earliest appears to be UK Patent 12869 for Improvements in Steam and other Fluid Pressure Engines held in association with the S.M. The alula is a small structure located at the joint between the hand-wing and arm-wing of birds and is known to be used in slow flight with high angles of attack such as landing. This is what I have found.Īlexander Albert Holle, Dutch and originally a tea planter, held many patents. The problems with the theory behind the alula wing are well covered in the attachments to various posts above so I thought I would add a bit of background regarding Holle.

Alula wing