83 Years Ago Today: Stinson Model 76 Accepted for Service Tests

August 7, 1941:

Just ten days after Stinson chief pilot Al Schramm took the new Model 76 (V-76) prototype aloft on its maiden flight, the Wright Field Experimental Engineering Branch accepted Stinson’s offer to loan the plane to the military for six weeks for field testing at Fort Knox Kentucky (HQ Armored Force), Fort Sill Oklahoma (HQ Field Artillery) and Fort Bliss Texas (HQ Cavalry). At each of these bases, the 12th, 15th, and 120th Observation Squadrons, respectively, were to test the airplane. He delivered the plane to Fort Knox four days later.

Schramm thought this was premature because the spin-testing of the new plane was not complete and an accident with a military pilot at the controls could end the development program. However, top management insisted that he take the plane on tour to these bases since Taylorcraft, Aeronca and Piper had already successfully participated in the Tennessee Maneuvers and had been invited to participate in the Louisiana maneuvers in September. It was a race against time.

The military had already rejected both their Model 10 (tested as the YO-54)) and the prototype tandem-seat Model 75B as prospective liaison planes, and the O-49 Vigilant (later L-1) program was currently in jeopardy of being terminated due to delivery delays and its high cost. Stinson needed to win a new military contract with a cheaper, simpler airplane soon or Vultee, who had assumed control of Stinson the previous August, was inclined to convert the factory to manufacturing parts for their other military planes such as the BT-13 trainer and Vengeance dive bomber.

As we we know, the V-76 was to impress the military with its performance and versatility  and be adopted as the O-62 Sentinel in November, but as Schramm explained in his self-published autobiography, the fate of Stinson as an independent designer and manufacturer of their own airplanes hung in the balance during the tense period of military field testing from mid-August through September 1941.

(Measuring V-76 takeoff distance at Ft. Sill, September 1941. NARA photo)

Fortunately, the Army Air Forces pilots did not have an accident with the plane during their six-week accelerated test program, but shortly after the Model 76 was returned  to Wayne, Michigan, Schramm was nearly killed when factory flight tests resumed. As he had warned might happen, an uncontrollable flat spin developed when the plane was loaded near its calculated aft center of gravity limit and it required a super-human effort on his part to avoid a fatal accident.

I’ll leave the fascinating details of that to a future telling of the story, but as a teaser I’ll say that Al Schramm could not bail out due to the high g-forces and he bent the control stick while trying to save himself. The engineers did not believe that to be humanly possible according to their calculations, but there it was. Luckily, Schramm did not end up having a street named after him as so many other test pilots did in those days of hazardous test-flying that has been made much safer by modern computer modeling.

To sum up, 82 years ago today – 7th August 1941 – was another important date in the development timeline of the Stinson L-5, the subject of my first book which I hope to publish soon.