GERMAN AIRLINER

Evening Star, Issue 22463, 7 October 1936, Page 15

GERMAN AIRLINER

HEAVY OIL ENGINES USED The visit to Croydon air port of a German airliner fitted with four 750fa.p. Diesel heavy-oil engines is a marked step forward in one of tho most important aviation developments of Hie present time (writes Major C. C. Turner, in the ‘ Daily Telegraph ’). In this country engines of this type are being fitted as an experiment into one of the new Blackburn flying boats, and in Franco the Air -Ministry has offered a prize of £135,000 for a heavyoil aero engine of French design and construction. The German machine was a Junkers G3B, carrying 34 passengers and a crew of seven. Heavy-oil engines, in which ignition is due to intense heat of compression in the cylinders, are now in regular use on some of the German air lines. Such engines are used also in the big German airships. The British airship RlOl had heavy-oil engines. On the German air lines there are five single-engined, two four-engined, one three-engmed, and one two-engined liners using Junkers heavy-oil engines. In Britain the Junkers “ Jumo 4 ” is made under license by Napiers, and some have been ordered by the Air Ministry. The principal British aero-engine makers are developing heavy-oil engines, but owing to important recent improvements in their fuel system petrol engines will not easily be ousted. They will certainly continue in use in certain classes of aeropane. The greater weight of heavy-oil engines prevented their adoption for flying until recent years; but now that the weight has been much reduced their fuel economy becomes an important factor. ON LONGER FLIGHTS. The advantage of this manifests itself in journeys exceeding about six hours. For the shorter flights of nmst military and civil aeroplanes the petrol engine is still preferred. Heavy-oil engines offer comparative but not absolute immunity from risk of fire. They require less fuel, thus saving in tankage space on long voyages. Tho oil costs about 9d a gallon, against about Is 6d lor petrol. The efficiency and economy of the Junkers heavy-oil engines are valuable over the long ocean route from the West Coast of Africa to South America. They are fitted to the “ Do. 18 ” flying-boats, and have extended the flight range of these machines to 2,670 miles without sacrifice of useful load. This is a good margin over the 1,860 miles of the South Atlantic stretch. Two “Jumo” engines, built under license in Franco, have been officially approved after a 50-hour test, and for the heavy-oil aero engine _ competition these engines will bo used in a “ Bernhard 82 ” long-rango bomber.