The Stearman M-2 Speedmail (nicknamed the Bull Stearman) was a mail-carrier aircraft produced by the

Stearman Aircraft Stearman Aircraft Corporation was an aircraft manufacturer in Wichita, Kansas. Although the company designed a range of other aircraft, it is most known for producing the Model 75, which is commonly known simply as the "Stearman" or "Boein ...

Company of Wichita, Kansas. It first flew in January 1929. The Speedmail was a single-seat biplane, with two large cargo compartments in place of a front cockpit. The fuselage and tail unit were constructed from welded chrome-moly steel tube faired with wooden formers and fabric covered aft of the pilot's cockpit, and detachable aluminium alloy panels covered the fuselage forward of the cockpit. The wings were constructed from spruce spars and plywood built-up ribs, all fabric covered. It differed from previous Stearman aircraft by having a tailwheel instead of a tailskid due to its size and weight.

Design and development

Varney Air Lines M-2 after accident exposing mail compartment Lloyd Stearman and Mac Short, (Stearman's V.P. engineering), designed the Speedmail to the requirements of

Varney Air Lines Varney Air Lines was an American airline company that started service on April 6, 1926, as an airmail carrier. Formed by Walter Varney, the airline was based in Boise, Idaho, United States. The airline is one of the predecessors of United Air ...

, which needed a new mail carrier with greater capacity to fly the Air Mail contracts they acquired from the U.S. Postal service while still being able to land on short, unimproved airstrips. This was achieved by using a new type of airfoil section, the Goettingen 398, allowing high lift at low speeds without affect the cruising speed. The result was a sturdy aircraft with a large cargo capacity. To enable Interstate Air Lines to fly passengers on its Air Mail routes from Atlanta, Stearman enlarged the M-2, into the LT-1(Light Transport).The three aircraft produced for Interstate Air Lines could carry four passengers plus mail. A further development was the CAB-1, "Stearman Coach", which was designed with an enclosed cabin for use as a business aircraft. However, only one was built.

Operational history

Varney Air Lines' pilots found the M-2 difficult to handle and the

Wright Cyclone Wright Cyclone was the name given to a family of air-cooled radial piston engines designed by the Wright Aeronautical Corporation and used in numerous American aircraft in the 1930s, 1940s and 1950s. Background The Wright Aeronautical Corporatio ...

engine was plagued with frequent maintenance issues. The sole surviving Stearman M-2 Speedmail is on display in the collection of the

Western Antique Aeroplane & Automobile Museum The Western Antique Aeroplane and Automobile Museum (WAAAM) is located in Hood River, Oregon, United States, adjacent to the Ken Jernstedt Airfield, Ken Jernstedt Memorial Airport. WAAAM is a nonprofit 501(c)(3) organization committed to the prese ...

in Hood River, Oregon, U.S.A.

Variants

Stearman LT-1 Light Transport Interstate Airlines NC8833 c

;M-2 Speedmail: Single-engine mail transport aircraft, powered by a 525 hp (391-kW)

radial engine, able to carry up to 1,000 lb (454 kg) of mail. ;

Stearman LT-1 The Stearman LT-1 (Light Transport-1) was a late 1920s American biplane, carrying four passengers plus mail. Design and development The LT-1 was a slightly enlarged version of the Stearman M-2 Speedmail with four passengers in an enclosed cabin ...

: Slightly larger 5-seat passenger and mail carrier, powered by a

Pratt & Whitney Hornet The Pratt & Whitney R-1690 Hornet was a widely used American aircraft engine. Developed by Pratt & Whitney, 2,944 were produced from 1926 through 1942. It first flew in 1927. It was a single-row, 9-cylinder air-cooled radial design. Displaceme ...

radial piston engine. ;CAB-1 Coach: Similar to the M-2 with enclosed cockpit filling gap between the fuselage and wing and powered with a 300 hp

Wright J-6 The Wright Whirlwind was a family of air-cooled radial aircraft engines built by Wright Aeronautical (originally an independent company, later a division of Curtiss-Wright). The family began with nine-cylinder engines, and later expanded to incl ...

-9.

Operators

; *

Specifications (M-2 Speedmail)

References

Citations

Bibliography

* * Lopez, Alan (2012). Bull Stearman: The Story of the Stearman M-2 Speedmail. Princeton: Mountain Press * * {{Stearman 1920s United States mailplanes M-2 Biplanes Single-engined tractor aircraft Aircraft first flown in 1929