On April 17, 1926, Western Air Service, Inc., commenced operation on Contract Air Mail Route 4 (CAM-4) between Los Angeles and Salt Lake City. via Las Vegas. For service over this route, a distance of about 660 miles, Western selected the Douglas M-2 aircraft, a mailplane version of the 0-2 observation plane produced by the Douglas Company to replace the U.S. Army DH-4 aircraft.
The Douglas M-2 was selected because it was far superior in strength, construction, performance, and flying characteristics to other aircraft entered in the Post Office Department’s competition for airmail airplanes. The M-2 was a single-bay biplane with the conventional form of axleless undercarriage. The fuselage, a truss of steel tubes and tie rods, was made in two detachable sections. The engine section was detachable at the station at the front wing beam and the engine cowling was hinged to facilitate inspection. The fuselage aft of the firewall was covered with fabric. The wings, vertical fin, and horizontal stabilizer were of standard wood beam and built-up rib construction, with the elevators and rudder made of Duralumin tubing. The power plant was a 400-hp, Liberty water-cooled engine, with nose radiator. Two main fuel tanks, each of sixty gallons capacity and made of sheet aluminum, were so mounted in the lower wing that they could be jettisoned by the pilot. A small 10-gallon gravity tank was located in the upper wing.
A design detail of particular interest was the location and construction of the M-2 mail compartment. It was situated in front of the pilots cockpit, sealed from the engine by a fireproof bulkhead, and lined with reinforced Duralumin. It was six feet long, had a capacity of 58 cubic feet, and could carry up to 1,000 pounds of mail. A unique feature was the provision of two removable seats that permitted carrying passengers or reserve pilots from one field to another. The passengers were seated well down in the compartment and protected by suitable windshields. Access was provided by the use of aluminum covers over the top, arranged and constructed so that, with passengers aboard, the roof door could be folded down. providing a cockpit opening.
Flights were scheduled daily in both directions on the Los Angeles-to-Salt Lake City run, with one-way flight time averaging slightly in excess of six hours. The record time for the route was 4 hours, 12 minutes. The schedule was maintained by four regular pilots, two reserve pilots, eight mechanics, and three radio operators at the fields. Although transporting the mail remained the airlines’ chief concern, Western Air Express invited passenger traffic, and invaluable experience was gained flying passengers in the M-2 over the same rugged territory of eastern California. southern Nevada, and western Utah traveled many years before by the Mormons.
The M-2 performed remarkably well during the early years on the CAM-4 route. Its load-carrying capability, remarkable stability, and rugged construction contributed to a perfect safety record and profitable operation. Government and airline experiences with the Douglas mailplanes and the 0-2 led to modifications of the basic design. Relatively minor changes in cockpit layout, engine accessories, and airframe construction led to the M-3 mailplane, which differed little in physical appearance from the M-2 version. A subsequent addition of five feet to the wingspan resulted in the final version, the M-4, which realized considerable gain in payload at a negligible loss in performance. While Western eventually added two M-4s to its fleet of six M-2s, the M-4 saw more extensive service with National Air Transport (later United Air Lines) from 1927 to 1930 on the Chicago-New York route. National Air Transport modified all of its M-3s into the M-4 configuration and eventually had twenty-four Douglas mailplanes on its roster, to become the largest operator of this type in commercial service.
The M-2 of the National Air and Space Museum is believed to be the last Douglas mailplane in existence. This machine is actually an M-4 model originally purchased by Western from the Post Office Department in June 1927 and registered as NC 1475, serial number 338. The aircraft saw considerable service on Western’s mail route until 1930. when it crashed and was sold to Continental Air Map Company of Los Angeles. The airplane had a series of corporate and private owners until it was reacquired by Western Air Lines in April 1940 and subsequently registered with the Federal Aviation Administration as M-2 NC15O, Western’s first M-2. The first substantial restoration took place in 1946, although no attempt was made to make it flyable. For the next twenty two years, the M-2 made its home in a corner of Western’s hangar at Los Angeles International Airport. In 1974 an intensive, large-scale restoration effort commenced, under the impetus of retired Western Captain Ted Homan.
Volunteers from Western Air Lines, McDonnell-Douglas Corporation, Goodyear Tire Company, and many other organizations completely rebuilt the aircraft and its Liberty engine, returning the machine to flyable condition. The M-2 flew for the first time in thirty-six years on June 2,1976, and after a series of test flights was recertified airworthy by the Federal Aviation Administration. After a successful transcontinental journey in May 1977, the venerable M-2, resplendent in the silver and red colors in which it flew the old Mormon Trail, is displayed as a lasting tribute to the men and women who pioneered the mail-passenger service during the formative years of commercial aviation in the United States.
