In 1928, the fledgling commercial aviation industry in the United States was flying high, thanks in large part to Charles A. Lindbergh’s epic solo flight from New York to Paris in 1927. The prairie city of Wichita, Kansas, benefitted greatly from “Lucky Lindy’s” flight. The city was home to three major airframe manufacturers – the Travel Air Company, Cessna Aircraft Company and the Stearman Aircraft Company. The latter had relocated to Kansas from California and was busy building open-cockpit biplanes for private, business and air mail operators.
The pace of production at the Stearman factory increased in the autumn of 1928, with more than half of the year’s output being built in the last three months of year. Since beginning operations in Wichita late in 1927, about 70 airplanes worth $500,000 had been manufactured, and production for 1929 was projected to approach 150 aircraft.
Company president Lloyd Carlton Stearman and chief engineer Mac Short decided that the time had come to design a cabin aircraft aimed at the growing number of executives using airplanes to expand their business. The emerging market for an enclosed-cabin aircraft was being driven chiefly by officials who had grown tired of flying in open-cockpit aircraft. Above all, they wanted a spacious, comfortable and well-equipped cabin environment suited to conducting business in the air.
Stearman’s and Short’s answer to those demands was designated the CAB-1 and marketed as the Stearman Coach. The ship was based largely on the M-2 Speed Mail that operated with Varney Air Lines in the Northwestern United States. The prototype CAB-1 made its debut at the aviation show in Detroit, Michigan, in April 1929 and made a favorable impression on the crowds.
Having a wingspan of 42 feet (upper wing panels, 30 feet lower wing panels) and a length of 29 feet, the CAB-1 was a large airplane by the standards of 1929. Painted in a two-tone cream and tan color combination with a contrasting scheme of cream and red with a black band and striping, one of the big biplane’s unusual features was its large cabin surrounded by windows that provided occupants an unprecedented 360-degree, in-flight view of the outside world.
The interior was fitted with plush, deeply upholstered seats for six people, plus two for the pilots, and was heated and insulated. A large baggage compartment on the left side of the fuselage allowed for easy loading and unloading of suitcases, golf clubs and small packages.
Stearman’s Coach was powered by a Wright Aeronautical nine-cylinder, R-975 static, air-cooled radial engine rated at 300 horsepower that was fed fuel by two tanks in the upper wing panels and a third tank below the cabin floor for a total capacity of 110 gallons. Maximum range was 480 statute miles.
The cockpit instrument panel was equipped with altimeter, airspeed and rate-of-climb indicators, tachometer and an eight-day clock. In addition, landing lights, flares, dual controls, mechanical brakes, a generator and an inertia starter were standard equipment.
During test flights the biplane cruised at 115 mph and demonstrated a maximum speed of 135 mph. Landing speed was a benign 47 mph. Weighing in at a hefty 4,270 pounds maximum takeoff weight, the CAB-1 could climb to an altitude of 16,000 feet and carry a payload of 780 pounds.
After the Detroit show ended the airplane embarked on a nationwide tour of Stearman distributors and made many demonstration flights with potential customers on board. Unfortunately, sales of the Stearman Coach were plagued by the ship’s price tag of nearly $10,000, its biplane configuration that was considered obsolete compared to more modern monoplane transports, and early signs that Wall Street was becoming unstable.
Although Lloyd Stearman reported having three firm orders for the Coach and planned to build 10 airplanes initially, by the end of of 1929, the lack of sales and the increasingly crowded market for new, expensive aircraft made it clear to Lloyd Stearman that the elegant, luxurious CAB-1 was nothing short of a colossal failure – a white elephant.
As a result, plans to begin production within 60 days of the Detroit exhibition were quickly scrapped and the sole ship was dismantled and soon disappeared from company literature and magazine advertisements.