NEW DEVICE FDR AIRCRAFT

Otago Daily Times, Issue 24750, 29 October 1941, Page 6

NEW DEVICE FDR AIRCRAFT

INCREASED EFFICIENCY' A device which may have far-reach-ing results on the performance of aircraft of the future has been produced in England. It is known as a constant speed contra-rotating airscrew, and consists of two three-bladed air-screws on the same engine rotating in opposite directions. It is claimed that the use of such an airscrew will eliminate swing and generally assist take-off; that it will allow of a reduction in the diameter of airscrews; will increase transmission efficiency; and that it will add considerably to the performance of fast aircraft when operating at high altitudes. The use of twin airscrews on the same engine, rotating in opposite directions, counteracts the effect of the slip-stream! and thus increases safety in take-off. This innovation should be particularly useful for fast ship-borne fighters, which must take off from and land on the deck of a carrier. It will also enable the engine nacelles on amphibian machines to be nearer the water. The fitting of the twin airscrew adqls only 471 b to the weight, the weight of the normal airscrew being about 4501 b, compared with ,4971 b for the contra-rotating equipment. Either metal or wooden blades of any type may be used.