AERONAUTICS: Packard's Diesel

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A Stinson-Detroiter monoplane glided down upon Langley Field, at Hampton, Va., one day last week and the two men who stooped out of her cabin asked army mechanics to help them trundle the plane at once into a hangar.

That done, they hauled tarpaulin, chain and padlocks from their cabin and securely shrouded their motor from prying eyes. They had reached Langley Field in 6 hrs. 50 min. flying time and they took precautions because, underneath the chain-wrapped tarpaulin, was the first diesel-type motor ever used successfully for airplane propulsion. The flyers were Mechanical-engineers Lionel M. Woolson and Walter Edwin Lees. Their employer, developer of something new and great in the air, was Packard Motor Car Co.

No patents now are obtainable on diesels or their modifications, for plane-power or other drive.* Several manufacturers have been experimenting with diesel modifications for aircraft. Some of their representatives were at Langley Field last week, attending the fourth annual Engineering Research Conference conducted by the National Advisory Committee for Aeronautics (initiated by President Wilson). It was to astonish their peers that Packard Engineers Woolson and Lees had flown the 650 wind-jostled miles from Detroit. It was to frustrate competitive inquisitiveness that they hooded their motor.

Five years Engineer Woolson and his research staff at the Packard plant have labored designing the motor. They had, first, the diesel principle to go on, i.e., that air can be heated by compression until hot enough to ignite a jet of fuel oil.

Their problem was to make such an engine light enough for efficient flying.

Their accomplishment, reached and tested episodically last year, is a nine-cylinder, radial, air-cooled motor. It lacks, of course, the sparkplugs, wires, magnetos, etc., essential in spark-ignited gasoline engines. A pipe line distributes oil under pressure to each of the cylinders. The present machine delivers 200 h.p., and is slightly less in diameter than gasoline radials of like power. It weighs nearly 3 Ib. per h.p., against the average 2 Ib. per h. p. of gasoline types. But it travels farther and more cheaply on a gallon of its fuel. For example, last week's 7-hour (actually 6 hr., 50 min.) astonishment flight required 54 gal. of oil, costing $4.68 and weighing 365 Ib. A gasoline radial would have required for the same trip 91 gal. of gas, costing $27.30 and weighing 546 Ib. On last week's short flight the gasoline engine and its fuel would have been slightly lighter than Packard's diesel and its oil. On longer flights with more gallons of fuel needed the diesel combination would obviously be the lighter. Other accomplishments included reductions of fire hazard (oil requires higher temperature than gasoline for ignition) and radio interference (by the electrical wires of the gasoline engine's ignition system).

Because no patents are obtainable, Packard is guarding its new product until it can get into production and thus "get the jump" on the rest of the industry. To that end the company has already started a special 300,000 sq. ft. factory and scheduled future production. And in anticipation of new profits Packard motor car stock last week began ascending.

Richthofen to Rickenbacker