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The Stinson O-54 was the designation given to six Stinson Voyagers ordered for evaluation by the USAAC. More aircraft were ordered during the Second World War, and others taken over from civilian owners, becoming the L-9, and the basic design became the basis of the very successful Stinson L-5 Sentinel. The same basic aircraft was also used by the RCAF, which ordered twenty and ordered in large numbers by the French, although very few were delivered before the collapse of France.
The Stinson Voyager was the company’s first true light aircraft. Work on it began in 1938, taking advantage of a new Lycoming engine. It was a high wing monoplane, with a fixed undercarriage. The wings were connected to the base of the fuselage by a pair of streamlined spars. The heavily glazed cockpit was directly under the wings, with the windscreen sloping forward from the wing leading edge. It had a tall horizontal tail structure.
Its wings used spruce spars, with metal ribs and leading edge and a fabric covering. The wing used a NACA 4412 aerofoil, with fixed leading edge slots and slotted flaps, which made it very difficult to spin the aircraft. The main fuselage structure was built around a steel tube framework with a fabric covering. The tail plane had a wooden structure.
The prototype made its maiden flight on 3 February 1939, using a 50hp Lycoming engine. The aircraft handled well, but needed more power, so a 75hp Continental A75-3 engine was used instead.
This was used in the first production model, the Model HW-75. This was marketed as the Stinson 105, based on its maximum speed. A total of 275 HW-75s were built, including twenty that saw service for the RCAF (after being sneaked across the US-Canadian border in civilian marks to bypass neutrality laws).
Next was the HW-80 (Model 10), which used a 80hp Continental A80-6 engine. A total of 260 of this model were built. The HW-80 almost became a major export success, after the French ordered 600 for their air force, but only a handful had been delivered before the collapse of France in 1940. One went to Britain, where it was evaluated by the RAE at Farnborough. This was also the version purchased by the USAAC, which bought six aircraft, powered by the Continental O-170-1 engine. These aircraft were given the designation YO-54.
In March 1940 Stinson submitted a standard Model 10 to a US Army competition that was looking for a less expensive liaison aircraft to use alongside the Stinson O-49. This had been ordered as the first of a new type of lighter liaison aircraft, replacing earlier models which resembled light bombers, and lacked the flexibility demonstrated by aircraft such as the Fieseler Storch. The Model 10 was let down by its performance on muddy fields, and wasn’t ordered by the USAAC at that stage. However the experience did inspire work on the Model 75B (using the parent company Vultee’s model number sequence), which had two men in tandem seats and used a 100hp Lycoming O-235 engine. The Model 75 later became the basis of the Model 76, which was produced in large quantities as the Stinson O-62/ L-5 Sentinal.
In 1941 Stinson produced the Model 10A/ HW-90 Voyager. This was powered by a 90hp Franklin 4AC-199-E3 engine and had a shorter engine cowling but was otherwise very similar to the earlier models. A total of 500 were built. Many were taken over by the Civil Air Patrol during the Second World War.
The USAAC also used the Model 10A. The first eight were ordered as Stinson AT-19A advanced trainers, powered by the Franklin O-200-1 engine, but were then redesignated as the L-9A. Another twelve civilian aircraft were taken over, becoming the AT-19B then L-9B. Slightly confusingly a version of the Stinson Reliant that was produced for British use from 1942 was then given the AT-19 designation.
Towards the end of the Second World War Stinson developed a larger four-seat version of the Voyager, the Model 108 or Voyager 150. This was the most commercially successful version of the family, with around 3,500 of three different versions produced in the late 1940s. Convair then sold their Stinson division to Piper, and another 1,760 Piper-Stinson Model 108-3s were completed, but these post-war models didn’t see military service.
HW-75
Engine: Continental A-75-3 four-cylinder air-cooled engine
Power: 75hp
Span: 34ft
Length: 22ft 2in
Empty Weight: 923lb
Gross Weight: 1,580lb
Maximum speed: 105mph
Cruising speed: 100mph
Climb rate: 430ft/ min at sea leve
Ceiling: 10,500ft
Range: 350 miles