The Stinson SR-10F Reliant was part of a series of powerful cabin airplanes outfitted as well-appointed executive and business aircraft or as sturdy utility craft and airliners. This particular aircraft participated in airmail pick-up experiments for All American Aviation and in the U.S. Army Air Force's 1943 experiments in fly-by pick-ups of ground positioned gliders and personnel.
Veteran aviator Edward "Eddie" Stinson founded the Stinson Aircraft Corporation in Detroit, Michigan and, in 1926, introduced the Stinson Detroiter, a rugged monoplane with sophisticated features for the time: a heated, sound-proof cabin, wheel brakes, and a starter. In 1928, the Stinson Aircraft Company produced the SM-2 Junior, a three-to four-place high-wing cabin monoplane for corporate and private use. In 1929, Stinson merged with E.L. Cord and the Cord Corporation for more secure financial backing. This merger allowed Stinson to offer its aircraft at lower prices and still develop new designs, the 1931 Model W and the 1932 Model R-2/3 series, the direct forebears of the famous Reliant series. Powered by Lycoming or Wright radial engines in the 200 to 300 hp range, these aircraft combined solid and reliable performance with plush cabin interiors.
In 1933, Stinson delivered the SR-1 and SR-2, and with a progression of refinements and engine upgrades, the series continued from the SR-4 to, in 1938, the SR-10. The SR-10s were truly the limousine class of personal transport with fine leather upholstery, walnut-faced instrument panels, and roll-down side windows similar to automobiles.
The SR-10 series was produced until the beginning of World War II when existing Reliants served assorted utility missions as UC-81s. Stinson later produced 500 military versions of the Reliants as the AT-19/V-77 for the British Royal Navy which used them mostly as instrument trainers along with utility passenger carrier and photo-reconnaissance work. About 350 AT-19/V-77 were returned to the United States after the war and refurbished by Stinson for the post-war civilian market. Many of these are still in existence today and can be seen at fly-ins of antique aircraft.
The Reliant was a ruggedly built airplane made mostly of welded chrome-moly steel tubing structures covered with fabric. The fuselage framework was faired to shape with wood formers and fairing strips. The fuselage forward of the doors was covered and faired with a duralumin sheet that included removable engine accessory panels. The single strut-braced, double-tapered wing was built with a girder-type spar with riveted square aluminum tubing ribs attached to the spars with riveted gussets. The leading edge was wrapped with duralumin sheet and the ailerons and slotted vacuum-operated wing flaps were of similar construction. The fabric-covered tail assembly was built of welded steel tubing with aerodynamically-balanced control surfaces and an adjustable horizontal stabilizer. The aircraft had a nine-cylinder Pratt and Whitney Wasp Junior radial that developed 450 hp for take-off and it was usually equipped with an aluminum two-blade Hamilton Standard constant speed propeller. The wide-tread cantilever landing gear was equipped with low-pressure tires and hydraulically-operated disc brakes. The SR-10F Reliant came equipped with a full complement of options including: instruments for poor weather flight, 12-volt battery system, electric starter, cabin heater and ventilation system, ash trays, cabin assist straps, shatter-proof glass, roll-down windows, navigation lights, landing lights, and leather upholstery. This final version of the Reliant was re-engineered by famed racing plane designer Gordon Israel with many refinements, such as retractable cabin entry steps.
Stinson Reliant SR-10F NC-2311 was completed on July 22, 1939 and was one of 18 of this particular model manufactured. The first owner was Harry Lunger of Wilmington, Delaware, who was associated with All American Aviation, a company owned by Richard DuPont and based in Wilmington. In 1942, Lunger sold the airplane to the company that reregistered it as NX-2311 and installed aerial pick-up equipment in the cabin and knife-edge cutters over the top half of the wheels and struts. All American's delivery and pick-up system, based on work by Dr. Lytel Adams, sought to bring airmail service to remote areas with limited accessibility and challenging weather conditions. On the ground, a rope attached to an airmail bag was strung out between two poles. After dropping a bag of mail from another line, the pilot flew so that a grappling hook (later a steel boom), lowered from the aircraft, hooked the rope's loop; then a winch reeled the bag into the aircraft. The cutters cut the ropes in case of an entanglement with the ground rig during a pick-up or delivery sequence. All American Aviation purchased a fleet of SR-10Cs in the late 1930s for airmail pick-up service in the mountainous areas of the Pennsylvania, West Virginia, Kentucky, and Ohio.
All American transferred NX-2311 to the U.S. Army Air Corps later that year and it was registered 43-7280 for experimental tests in the rescue and recovery of aircraft and people. After tests with dummies and live sheep as pick-up objects, Lt. Alexis Doster was the first person to be picked up from the ground on September 4, 1943, at the Clinton County Airport in Ohio. Captain Norm Rintoul, a former All American pilot, piloted the Stinson. When someone suggested a chimpanzee as a possible pick-up candidate, Captain Rintoul reportedly stated, “If you use that ape, you had better teach her to fly, because when she comes in one side, I'm going out the other side." After completion of the pick-up experiments, the airplane was used for a number of other research assignments and it was also in an accident before the Army declared it surplus in March 1945.
On March 26, 1946, All American registered it with its previous civilian NC-2311 number. They removed the pick-up winch equipment and installed standard rear seating for passenger service. In 1947, Rintoul, back again with All American, purchased the Reliant from All American, reinstalled the pick-up equipment, and then flew it on the air-show circuit demonstrating human pick-ups. One of the last human pick-up subjects was Bernie Caine, an Allegheny Airline mechanic who maintained the Reliant.
In 1949, Rintoul offered to donate the airplane to the National Air Museum. Before it was flown to Museum's Park Ridge, Illinois facility for storage, Rintoul's checkerboard design on the rudder and nose cowl was repainted to NC-2311's unique All American Aviation colors of all black with orange trim (most were maroon). In August 1966, Allegheny Airlines borrowed the airplane for display during the inauguration of their DC-9 service. It was then stored at the Garber Facility in Suitland, Maryland until 1993, when it was restored and lent to the Smithsonian's National Postal Museum in Washington, DC.