The gyro instruments soon proved their value and were installed in the cockpits of transport planes the world over. The Sperry Gyropilot then was perfected. This remarkable instrument, based on the gyroscope movement, was developed actually to manipulate automatically the controls of even the largest airplane, keeping it directly on the desired course and leaving the human pilots free for their many other duties.
In 1933, Wiley Post flew around the world alone, but the Gyropilot piloted the Winnie Mae over most of the route. This relieved the fatigue of constant flying and allowed Wiley to keep a continual check on his maps. His successful use of the automatic pilot soon caused its adoption by most of the major airlines of the country.
Thus, with the aid of the radio beam, better flight instruments, special octane gasoline, two-way radio, sound-proofing, wheel brakes, and adjustable pitch propellers, the airlines of America were fast emerging into a safe and comfortable means of travel.
While the DC-2 was coming into prominence in the air transport field, Boeing engineers had gone on with their idea of a two-engined plane and had built an all-metal bomber for the Army.
In building the two-engined, all-metal B-9, Boeing engineers learned how to build another plane with a more peaceful purpose. This ship was the famous Boeing 247-D commercial transport plane. The 247-D was an all-metal, low-wing monoplane, powered with two 550-horsepower Pratt & Whitney Wasp radial engines. It had a top speed of 200 miles per hour and a cruising speed of 180 miles per hour. It was America’s first three-mile-a-minute air transport plane.
In designing the speedy 247-D, the Boeing did not forget the comfort of the passengers. The plane was fully heated and ventilated. Its seats were deeply upholstered and had reclining backs. There were broad windows at each chair. There were dome lights and individual reading lamps; and the plane was equipped with a tiny galley and a complete lavatory. Insulation kept the 247-D quiet and comfortable in any sort of weather.
The 247-D carried ten passengers, a pilot, co-pilot, and stewardess, plus baggage and mail. It was first put into service by the United Air Lines in 1933, on their coast-to-coast route. Incidentally, it was United who had introduced to the airlines the third member of the air transport’s crew, the stewardess. The pretty young stewardesses were all trained nurses. They looked after air-sick passengers, served food en route, and looked after the comfort of the air travelers.
