Safety in the Air

Sun (Auckland), Volume II, Issue 456, 11 September 1928, Page 9

Safety in the Air

A ustra lia ti s In vcti tion SIMILAR TO SLOTTED WING According: to aviation experts i£ the compound ■wing device invented by Mr. A. C. Wragg, an Australian, which was successfully tried out on a Sikorsky plane at Garden City, United States, proves as effective as the patent Hand ley Page slotted wing, it will do much toward safety in flyiug. The Wragg invention was brought before the notice of the R.A.A.F. authorities in 1926, when it was thoroughly examined and a report made. Since that time no material subsequent information has come to hand, but it would appear as if very important modifications to the design have been made, judging by the reported success of the trials. Australian experts believe that the invention possibility resembles the Handley Page slotted wing, which has been so successfully tried out in Britain. The Moths which have been ordered by the Australian Commonwealth Government, are to be fitted with the device, and there are a few here already so fitted. The eightpassenger D.H.61, ordered by Mr. Ronald Knott, of Sydney, for a flight to the New Guinea goldfields, will also have the attachment. Danger of Stalling Commenting on the Wragg device and its prototype, a civil aviation official said: “There is but little doubt that 90 per cent, of serious aviation accidents in the past have been caused by the machine spinning to ground after an involuntary ‘stall.’ This spin, after ‘stall,’ will be practically eliminated when all airplanes are fitted with the Handley Page slotted wing, or a similar device, which enables the pilot to maintain control of his machine even when it is in a ‘stalled’ position. “It is difficult to estimate the value of devices of this nature on popular estimation of flying as a safe form of transportation.” The wisdom of permitting airplane patents, of which the extra cost might have the effect of retarding the popularity of aviation, was brought up by another expert. “In the case of the Handley Page device,” he remarked, “the patentee charges 5 per cent, on the capital value of the machine for the attachment. In a Moth costing! £6OO Othe extra £3O does not matter much, but in a £5,000 or £IO,OOO plane the 5 per cent, additional cost is a very great expense. “Throughout the world it is now generally recognised that inventors cannot secure patents for airfoil sections or a new design for a plane, but only for patents embodying a new jn-inciple. Apparently the-authorities have agreed that the Handley Page device offers an entirely new principle,