THE ALBATROSS

Otago Daily Times, Issue 23685, 17 December 1938, Page 32

THE ALBATROSS

STREAMLINED SPEED AND ECONOMY NOVEL CONSTRUCTION FEATURES (From Our Own Correspondent) (By Air Mail) " ii .. " LONDON, Nov. 17. .Official performance figures of the Albatross four-engined monoplane airliner, ninety-first de Havilland design, justify expectations based on its purity of form and exceptionally low head resistance. Test flights have shown that, with its four Gipsy-Twelve engines each delivering only 325 h.p.— 62 per cent, of their take-off power—the Albatross carries its full payload and fuel at a cruising speed of 210 m.p.h. • For purposes of comparison with the ideal, mathematicians have assumed tP at ,,&? weight of the Albatross and its 4000 square feet of exposed surface is represented as a pane of glass of negligible thickness towed edge on through the air by the same equivalent power as is needed to drive the aeroplane forward at 210 m.p.h. Then this perfectly streamlined object would travel at 259 m.p.h., or only 49 m.p.h. faster than the Albatross. A'erb* dynamically, therefore, the aeroplane is 81 per cent, perfect—an extraordinarily high figure. This excellent aerodynamical rendering is directly reflected in economical running. The Albatross, in passenger form and carrying a crew of four and enough fuel fpr a normal airline journey of 600 miles, transports 2.4 tons of payload a distance of 210 miles in an hour, while consuming 83 gallons of fuel. Its " power-enonomy " factor—a vital detail in airline working—is, therefore, 6.07 ton/miles of payload per gallon, a figure unequalled up to. the present by any airliner of comparable speed and payload capacity.

"LOBSTER'S CLAW" FUSELAGE The fuselage and the stressed skin monoplane wings are exquisitely formed, deriving from the structure of the Comet twin-engined racing monoplane which in 1934 won the EnglandAustralia speed and handicap races, and has since established record times over many long journeys. The four engines are installed in a fashion planned to keep down head resistance to the minimum. The Gipsy-Twelve engine, which has two inverted banks of air-cooled cylinders, has low frontal area, and though the wings of the Albatross are extremely thin, no less than 55 per cent, of the frontal area of the engines is absorbed in the thickness of the wings. Each engine is closely encowled in a bullet-shaped nacelle, the form of which is unimpaired by a scoop to admit cooling air; instead the air is brought in through apertures in the leading edges of the wings at controlled pressure and rate of flow. Novel methods of construction are embodied in the fuselage. It is circular in cross section, and is built like a lobster's claw. A double stress-bear-ing shell, with an inter-layer of light stabilising material and hermetically sealed by films of synthetic resin, makes up the structure. 3300 MILES WITH MAILS Two Albatross aircraft have been built for long-distance mail flying. The specification to which they were built called for the transoort of 10001 b of mails over a distance of 2500 miles nonstop against a continuous headwind averaging 40 m.p.h. The aeroplane produced to fulfil these exacting requirements actually has a range in still air of 3300 miles, with the tanks full to their maximum aggregate capacity of 1320 gallons. It is equipped for operation by a crew of three, for whom resting quarters are provided in one of the fuselage compartments. An automatic pilot is installed. Loaded to maximum weight of 32,5001 b, the Albatross can maintain a height of 11,900 feet with one outboard engine stopped and the three others giving out only their normal " climb" power of 390 h.p. each. The fuel tanks are provided with jettison valves for use in extreme emergency, but the security margin implicit in ability to continue flight with an engine out of action should eliminate forced landings. FAST TRAVEL OVER EUROPE The first of the passenger-carrying Albatross aeroplanes, called by Imperial Airways the "Frobisher," will shortly be commissioned for service on European routes. In this form the monoplane carries 22 or 23 passengers in three main saloons. There is a vestibule and main entrance aft. Other compartments comprise a lavatory, a space for mail or hand luggage, a radio cabin, and a baggage hold behind the passenger quarters. The crew of four —pilot, first officer, radio operator, and steward —have a separate entrance forward. For " short-haul" runs the Albatross may comfortably accommodate 30 or 32 passengers. In another form, known as the Albatross " Nightrider," simple and rapid adjustment of the seating provides luxurious sleeping berths for twelve, arranged as three upper and three lower berths on each side of a wide aisle, with a bedside armchair for each passenger.