Stinson Reliant

The Stinson Reliant was a popular single-engine four to five seat high-wing monoplane manufactured by the Stinson Aircraft Division of the Aviation Manufacturing Corporation of Wayne, Michigan.

Design and development
The Reliant is a three-place high-wing fixed tailwheel land monoplane powered with a variety of radial engines.

1,327 Reliants of all types were made from 1933 to 1941, in different models, from SR-1 to SR-10. The final commercial model, the Stinson Reliant SR-10, was introduced in 1938. A militarized version was first flown in February 1942 and remained in production through several additional versions (all externally identical) until late 1943 for the US and British armed forces. Reliant production can be broken into two distinct types - the straight wing Reliants (all models up to SR-6) and the gull wing Reliants (all models from SR-7 and after including the militarized V-77/AT-19) with there being little in common between the two groups of types. The straight wing Reliant had a wing of constant chord and thickness which was supported by two struts each side with additional bracing struts. In contrast the taper wing Reliant had the broadest chord and thickness of the wing at mid span, with the outer wing trailing edge heavily angled forward and a rounded cutout on the leading edge root, all supported by a single strut. The taper wing had a significant step up between the fuselage and the wing, and the changes in wing thickness gave it a distinct gull appearance from the front.

Operational history
The Reliant was used by the U.S. Army in World War II as a utility aircraft, designated UC-81, and as trainer designated AT-19. They were also used by the Royal Navy and Royal Air Force for light transport and communication duties. After the war they were sold on the civilian market as the Vultee V-77.

The V-77 was a spartan version of the SR-10 with the 300 hp Lycoming R680-E3B, a single door on the left side and the traditional "Bump" cowl was replaced with a simpler smooth cowl. Internal structure was beefed up significantly over the commercial models and a distinctive triangle shaped counterbalance was added to the rudder.

Variants
The SR-10 Reliant was available as a landplane, seaplane and skidplane in the following configurations:


 * Ambulance (2 Stretchers)
 * Cargo/Ambulance
 * Target Towing
 * Firefighting
 * Photographic

Civilian variants

 * SR Reliant: Powered by a 215 hp Lycoming R-680 radial piston engine.
 * SR-1: Powered by a 240 hp Lycoming R-680-2 radial piston engine. Two built.
 * SR-2: Powered by a 240-hp (179-kW) Lycoming R-680-7 radial piston engine.
 * SR-3: Similar to the SR-1, but with minor structural changes.
 * SR-4: Powered by a 250-hp (186-kW) Wright R-760-E radial piston engine.
 * SR-5: Improved version, powered by a 225-hp (168-kW) Lycoming R-680-4 radial piston engine.
 * SR-5A: Powered by a 245-hp (183-kW) Lycoming R-680-6 radial piston engine.
 * SR-5B: Powered by a 240-hp (179-kW) Lycoming R-680-2 radial piston engine.
 * SR-5C: Powered by a 260-hp (194-kW) Lycoming R-680-5 radial piston engine.
 * SR-5E: Powered by a 225-hp (168-kW) Lycoming R-680-4 radial piston engine.
 * SR-5F: Powered by a 250-hp (186-kW) Wright R-760-E radial piston engine.
 * SR-6: Five-seat cabin aircraft, powered by a Lycoming R-680-6 radial piston engine.
 * SR-6A: Four-seat cabin aircraft, powered by a 225-hp (168-kW) Lycoming R-680-4 radial piston engine.
 * SR-6B: Four-seat cabin aircraft, powered by a Lycoming R-680-5 radial piston engine.
 * SR-7: First gull wing series.
 * SR-7B: Five-seat cabin aircraft, powered by a Lycoming R-680-B6 radial piston engine. 47 built.
 * SR-7C: Five-seat cabin aircraft, powered by a Lycoming R-680-B5 radial piston engine. Three built.
 * SR-8A: Four-seat cabin aircraft.
 * SR-8B: Four-seat cabin aircraft, powered by a Lycoming R-680-B6 radial piston engine.
 * SR-8C: Four-seat cabin aircraft, powered by a Lycoming R-680-B5 radial piston engine.
 * SR-8D: Four-seat cabin aircraft, powered by a Wright R-760-E2 radial piston engine.
 * SR-8DM: Utility transport version of the SR-8D.
 * SR-8E: Five-seat cabin aircraft, powered by a 320-hp (239-kW) Wright R-760-E23 radial piston engine.
 * SR-8DE: Utility transport version of the SR-8E.
 * SR-9:
 * SR-9A:
 * SR-9B: Powered by a Lycoming R-680-B2 radial piston engine.
 * SR-9C: Powered by a Lycoming R-680-D5 radial piston engine.
 * SR-9D: Powered by a Wright R-760-E1 radial piston engine.
 * SR-9E: Powered by a Wright R-760-E2 radial piston engine.
 * SR-9F: Powered by a Pratt & Whitney R-985 radial piston engine.
 * SR-10:
 * SR-10B: Powered by a Lycoming R-680-D6. One built.
 * SR-10C: Powered by a Lycoming R-680-D5 engine. 46 built.
 * SR-10D: Wright R-760E-1 engine. 3 built.
 * SR-10E: Powered by a Wright R-760E-2 radial piston engine. 21 built.
 * SR-10F: Powered by a Pratt & Whitney R-985 Wasp Junior SB radial piston engine. 18 built.
 * SR-10G: Powered by a Lycoming R-680-E1 radial piston engine. 12 built.
 * SR-10J: Lycoming R-680-E3 engine. 11 built.
 * SR-10K: Wright R-760E-3. Two built.

Military variants

 * AT-19
 * USAAF designation for a training variant of the UC-81 for the Royal Navy under Lend-Lease as the Reliant I, 500 built.


 * AT-19A
 * Original designation of the L-9A which was a Voyager not a Reliant.


 * AT-19B
 * Original designation of the L-9B which was a Voyager not a Reliant.


 * AT-19C
 * Conversions of AT-19s for photo-survey aircraft for the USAAF, 51 conversions.


 * UC-81:
 * Four impressed SR.8Bs.


 * UC-81A
 * Two impressed SR.10Gs.


 * UC-81B
 * One impressed SR.8E.


 * UC-81C
 * Three impressed SR.9Cs.


 * XC-81D
 * One civil SR.10F operated by the military for the development of glider pick-up techniques.


 * UC-81E
 * Four impressed SR.9Fs.


 * UC-81F
 * Seven impressed SR.10Fs.


 * UC-81G
 * Three impressed SR.9Ds.


 * UC-81H
 * One impressed SR.10E.


 * UC-81J
 * Nine impressed SR.9Es.


 * UC-81K
 * Five impressed SR.10Cs.


 * UC-81L
 * Two impressed SR.8Cs.


 * UC-81M
 * One impressed SR.9EM.


 * UC-81N
 * Two impressed SR.9Bs.


 * L-12
 * Two SR.5As impressed into service with the USAAF during World War II.


 * L-12A
 * Two SR.7Bs impressed into service during World War II.


 * RQ-1
 * One SR-5 Reliant was acquired by the US Coast Guard in 1935, later redesignated XR3Q-1 and decommissioned in 1941.


 * XR3Q-1
 * One SR-5 Reliant was acquired by the US Navy in 1935.


 * Reliant I
 * 500 Reliants were supplied to the Royal Navy under Lend-Lease. The Reliants were used for light transport and communications, navigation and radio training duties.

Military operators

 * Argentine Navy
 * Royal Australian Air Force - 1
 * Royal Air Force
 * No. 510 Squadron RAF
 * Fleet Air Arm
 * 🇺🇾 Uruguay
 * Uruguayan Air Force
 * United States Army Air Forces - A total of 47 Reliants impressed during World War 2
 * United States Coast Guard
 * United States Navy
 * United States Army Air Forces - A total of 47 Reliants impressed during World War 2
 * United States Coast Guard
 * United States Navy
 * United States Navy

Civil operators

 * Aerolloyd Iguassu
 * Aerovias Minas Gerais
 * NAB – Navegação Aérea Brasileira
 * Grupo TACA
 * Aeronaves de México - the Reliant was the first aircraft used by Aeronaves, later to become Mexico's largest airline, Aeromexico, on their initial service between Mexico and Acapulco on 14 September 1934
 * Widerøe
 * Líneas Aéreas de Transporte Nacional (LATN)
 * Northwest Airways
 * Widerøe
 * Líneas Aéreas de Transporte Nacional (LATN)
 * Northwest Airways
 * Líneas Aéreas de Transporte Nacional (LATN)
 * Northwest Airways
 * Northwest Airways