This 75 horsepower civilian high-wing design was built by the Stinson Aircraft Company at Wayne, Michigan and first flew in 1939.
Economical, spin resistant and easy to fly, the plane was popular with aircraft owners and flight schools and by the end of 1939 Stinson was building three per day.
In the postwar era, the fuselage of the Model 10A was lengthened to accommodate four passengers and the four-cylinder powerplant was replaced with a Franklin 150 hp six-cylinder engine.
During the summer of 1940, Stinson built an experimental tandem-seat version of the HW-75, equipping it with a 100 hp (75 kW) Lycoming engine.
The V-75C failed to meet military requirements, so the Stinson engineers went back to the drawing board and came up with a clean-sheet design that was similar in concept to the V-75C but was a far stronger, more powerful and completely new tandem-seat airplane that met rigorous Army-Navy engineering standards for the design of military aircraft.
[1] Adopted by the Army Air Forces as their standard liaison aircraft, replacing the larger and more costly L-1 Vigilant, the primary purpose of the L-5 was short range officer transport, courier work and artillery spotting.
[1] In addition to the previously listed uses, L-5s were employed in many diverse roles such as reconnaissance, search & rescue, aerial photography, forward air control of fighter-bombers, laying communication wire, spraying pesticides, dropping para-cargo, dropping leaflets, and aerial broadcasting with loudspeakers.
[1] The L-5 series was manufactured between November 1942 and September 1945, during which time 3,590 of the unarmed two-seaters were delivered for military service, making it the second most widely used light observation liaison aircraft of the war behind the Piper L-4 Cub.
The use of aluminum, which was in critically short supply and more urgently needed for other aircraft, was limited to the engine cowling, tail cone, framework for the ailerons, rudder and elevator and the landing gear fairings.
Capable of operating from short unimproved airstrips, the L-5 Sentinel delivered personnel, intelligence and supplies to the front line.
An unusual use of the Sentinel was launch and recovery from a land-based overhead cable system designed by Lt. James Brodie that could be quickly set up in a large clearing that was otherwise unsuitable for a runway.
The cable was strung between two tall masts and a braked carriage snagged an arresting hook attached to the top of the airplane.
After World War II, the L-5 was used in the continental United States, Hawaii and Alaska by the Civil Air Patrol for search and rescue work.