Versatile, durable, and an important aircraft of World War II, the L-5 flew a wide variety of missions: photo reconnaissance, resupply, evacuation of wounded, message courier, VIP transport, and artillery spotting. Its design was roughly derived from the pre-war Stinson Model 105 Voyager. The Army Air Corps purchased six Voyagers from Vultee Aircraft (which had acquired Stinson) in 1941 for testing. Refitted with the Lycoming O-435-1 engine, the aircraft was designated the Model 75. While it had features and components of the Voyager series, it was fundamentally a new design.
The Army ordered this model in quantity, designating it first as the O-62 ("O" for observation), then as the L-5 ("L" for liaison) when the type designation was changed in 1942. This aircraft was the first O-62/L-5 produced.
The L-5 is one of the most important but overlooked aircraft of the Second World War. Versatile and durable, the L-5 flew a wide variety of missions: photo reconnaissance, resupply, evacuation of wounded, message courier, VIP transport, and artillery spotting.
The design for the Stinson L-5 Sentinel was roughly derived from the pre-war Stinson Model 105 Voyager. In 1941, the Army Air Corps purchased six Voyagers specially fitted with improved engines from Vultee Aircraft (which had acquired Stinson in 1940) for testing, designating them the YO-54. This version was underpowered.
Once fitted with a more powerful engine, the six-cylinder 185hp Lycoming O-435-1, the YO-54 was redesignated as the Model 75. This version incorporated some features and components of the earlier Voyager series, but was fundamentally a new aircraft design. The Army ordered this model in quantity, designating it first as the O-62 ("O" for Observation), and subsequently as the L-5 when the type designation was changed in 1942, indicating "Liaison" aircraft.
As the war went on, Stinson produced a number of variants: the L-5A was a modified L-5 with an improved electrical system; the L-5B had a deeper fuselage to carry a stretcher; the L-5C was equipped with a reconnaissance camera; the L-5E had improved control surfaces; and the L-5G had a more powerful engine. All told, Stinson produced more than 3,800 Sentinels before production ended. The Army also confiscated a number of civil Voyagers and pressed them into military service with the designation AT-19 (later L-9).
During the war, the Army transferred 306 L-5Bs to the Marine Corps and 152 to the Navy as OY-1s. After some modifications, 30 of these became OY-2s. Britain's Royal Air Force (RAF) also received 100 L-5 and L-5B aircraft under Lend-Lease. The RAF designated them the Sentinel Mk. I (L-5) and Mk. II (L-5B) and they served with distinction mostly in Burma. When the war ended, many L-5s were sold as surplus but some remained to serve in Korea and other areas during the Cold War. The post-World War II Sentinel was designated the U-19.
The NASM Sentinel is an L-5, U. S. Army Air Forces serial number 42-14798. It is the first production L-5 built but unfortunately, nothing is known of its flying career. The Air Force transferred it to the Smithsonian on June 5, 1960.