Stearman M-2 Speedmail

Last updated
M-2 Speedmail
Stearman M-2.jpg
The last surviving Stearman M-2 aircraft
General information
TypeMail carrier
National originUnited States
Manufacturer Stearman Aircraft Company
Designer
Number built7
History
First flight15 January 1929
Developed into Stearman LT-1

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

Contents

Design and development

Varney Air Lines M-2 after accident exposing mail compartment Stearman M-2 c.n 1001 NC9051 of Varney Air Lines (14) NC9051 after accident.jpg
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, 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. [1]

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. [1]

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. [1]

Operational history

Varney Air Lines' pilots found the M-2 difficult to handle and the Wright Cyclone 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 in Hood River, Oregon, U.S.A. [2]

Variants

Interstate Airlines Stearman LT-1 Stearman LT-1 Light Transport Interstate Airlines NC8833 c.n 2003.jpg
Interstate Airlines Stearman LT-1
Stearman CAB-1 Coach 1929 Stearman CAB-1 Coach NX8808 c.n 3001.jpg
Stearman CAB-1 Coach
M-2 Speedmail
Single-engine mail transport aircraft, powered by a 525 hp (391-kW) Wright Cyclone radial engine, able to carry up to 1,000 lb (454 kg) of mail.
Stearman LT-1
Slightly larger 5-seat passenger and mail carrier, powered by a Pratt & Whitney Hornet 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-6-9.

Operators

Flag of the United States (23px).png  United States

Specifications (M-2 Speedmail)

Data from Specifications of American Commercial Airplanes [3]

General characteristics

Performance

See also

Related development

Aircraft of comparable role, configuration, and era

References

Citations

  1. 1 2 3 Phillips, Edward (2006). Stearman Aircraft: A Detailed History. North Branch, MN: specialtypress. pp. 70–75. ISBN   9781580070874.
  2. ↑ "Stearman M-2 Speedmail - Western Antique Aeroplane & Automobile Museum".
  3. ↑ Aviation March 22, 1930, pp. 607, 609, 611.

Bibliography

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