Boeing designed the Model 40 in 1927 and the four-seat 40B-4 derivative was used on the 1,918 mile air mail route from San Francisco to Chicago. The rugged aircraft had a 525 h.p. P&W Hornet powerplant. Obtained from United Airlines 60 years ago.
The Model 40 was Boeing's first passenger aircraft. Two pax sat in the forward cabin and up to 2500 lbs of U.S. Mail was carried. C.A.M.18 was from San Francisco to Chicago - as marked on the "Arrow" insignia. This aircraft was built as a 40A with a 420 hp P&W Wasp, but was converted to a 40B by replacing the engine with a 525 hp P&W Hornet. This gave the 40B a cruise of 110 mph over 550 miles. Obtained from UAL 60 years ago.
This was the first Boeing Model 40A which made its maiden flight on 20 May 1927. Delivered to Boeing Air Transport for operation on their airmail routes. Two passengers sat in the enclosed cabin in front of the pilot. Powered by a P&W R-1340 Wasp of 420 h.p. From Boeing 60 years ago.
The Model 40B-4 was designed to carry four passengers and a substantial load of mail. Pacific Air Transport used theirs on Contract Airmail route C.A.M.8 between Seattle and Los Angeles. The pilot sat in an open cockpit just ahead of the circular "Boeing System" insignia. From Boeing 60 years ago.