L-5 History Blog #13 - Stinson L-5 Club

October 30, 1941

Procurement of Stinson Model 76 recommended.

Proitotype Model 76 — Model 76 prototype, designated YO-62. Note early smaller tail fin (SDAM)

On October 30, 1941 the Experimental Engineering Section at Wright Field published its report on the new Stinson Model 76 airplane that had been test flown during August and September by observation squadrons located at Forts Sill, Knox, Bliss, and Benning. Their confidential report XPM-M-50-604 concluded that the new plane was preferable to the Stinson O-49 Vigilant (which had a significantly shorter takeoff and landing run) because of lower price and simpler maintenance, while its performance was superior to the other light aircraft that had been tried. In other words, it represented a compromise between utility and cost. The other planes evaluated included the YO-54 (Stinson 105), YO-55 (Ercoupe 415), YO-57 (Taylorcraft Model D), YO-58 (Aeronca Defender), and the YO-59 (Piper J-3 Cub). The Stinson Model 76 was designated YO-62 for the tests.

As a result of the hurried summer trials, procurement of a service test quantity of Model 76’s was strongly recommended by the Wright Field chiefs. The estimated cost was $10,000 per airframe, approximately one-third that of the O-49. Approval for a modest 13-plane acquisition was made on November 24th and that marked the beginning of a procurement program that would stretch to a production run of 3,590 Sentinels over the next four years.

The Wright Field memorandum followed on the heels of another important report that had been circulated within the War Department just three days earlier by General Emmons, head of the recently established Air Force Combat Command. The investigation of his office into the performance of the Piper, Aeronca and Taylor airplanes experimented with during the recent large-scale army field maneuvers, coupled with previous studies done on the traditionally-equipped French, British and Polish observation squadrons that performed so dismally in combat during 1939 and 1940, led Emmons to propose a revamping of their similalarly equipped counterparts in the U.S. Army Air Forces.

General Emmons recommended the organization of two types of observation squadrons: a light observation squadron equipped with 12 liaison and 6 pursuit aircraft, and a medium observation squadron with 6 liaison, 6 bombardment, and 6 pursuit types in the lineup. His plan was to allocate one light squadron per infantry division, one medium observation squadron for each cavalry division, armored division, and army corps, and 2 medium squadrons for each field army. In addition, a photo squadron equipped with 6 twin-engine bombers and 12 pursuit types was recommended for each field Army as well as the Armored Force.

Emmons’ proposed setup was adopted with some modifications but it was relatively short-lived. By the end of 1942, “observation aviation”, as it was generically referred to, had shown grave weaknesses during the North African campaign following the Operation Torch landings in Morocco and Algeria, so the whole USAAF observation program was overhauled once again. Among other changes, the observation squadrons were removed from army ground forces control and placed under centralized Army Air Forces jurisdiction, and the weapon-carrying bombers were deleted in favor of faster, higher-flying unarmed types.

The observation squadrons were re-named reconnaissance squadrons, more in keeping with their mission, and they were equipped with photographic versions of high performance single and twin-engine aircraft. At the same time, a new type of unit was born – the liaison squadron – that was intended for army courier and communication work. Each of these new light plane squadrons would eventually be equipped with thirty-two L-5’s apiece, with one squadron attached to each field army or army group. In the mean time, the Army won approval for its own “organic” light airplanes to be used for artillery spotting. Due to strong opposition from the Army Air Forces, their planes were limited to no more than 100 horsepower by the War Department and the docile Piper L-4 Cub became the favored choice.

YO-59 at Wright Field 1941 — Piper YO-59 at Wright Field. The Y stood for service test aircraft (AFHRA)

To sum up the importance of this day in October 1941, the two separate recommendations for the addition of light aircraft to the Army and Air Forces arsenals showed that the slow, vulnerable civilian-type planes had finally gained general acceptance among the “top brass” as a viable weapon of war. Of course, a major reason for that was their low cost, but ultimately, given the relatively small numbers procured and their lilliputian stature compared to other combat aircraft, the little green “flivvers“, “puddle-jumpers”, “grasshoppers” and “flying jeeps” ended up making a disproportionately large contribution to success of the allied war effort. As All Hallows’ Eve passed in 1941, not even the most vociferous boosters of these simple, unarmed tube-and-fabric creations could have predicted their outstanding future success in battle.

AN HISTORICAL PERSPECTIVE

Jim Gray’s L-5 History Blog for October 30, 2020 – What Happened 79 Years Ago Today

On October 30, 1941 the Experimental Engineering Section at Wright Field published its report on the accelerated tests of the Stinson Model 76 airplane that had taken place during August and September at Forts Sill, Knox, Bliss, and Benning. Report XPM-M-50-604 concluded that the Model 76 was preferable to the better-performing Stinson O-49 Vigilant because of the much lower procurement cost and simpler maintenance, and its performance was still superior to the other light aircraft that had been tried. The other planes evaluated included the Stinson 105 (YO-54), Ercoupe 415 (YO-55), Taylorcraft Model D (YO-57), Aeronca Defender (YO-58) and Piper J-3 Cub (YO-59).

As a result of those tests, procurement of a modest quantity of V-76’s for further service trials was recommended. The estimated cost was $10,000 per airframe and approval for purchase of 13 planes was made in November. That set the course for the eventual procurement of 3,590 Sentinels over the next four years. [Note: You can read about that in my blog posted on November 24th, 2019.]

Model 76 prototype. Note early small vertical stabilizer. (SDAM)

The Wright Field memorandum followed on the heels of another important report that had been circulated within the War Department just three days earlier by General Emmons, head of the newly established Air Force Combat Command. The investigation of his office into the promising performance of the Piper, Aeronca and Taylor airplanes experimented with during the recent large-scale army field maneuvers, coupled with previous studies done on the traditionally-equipped French, British and Polish observation squadrons that performed so dismally in combat during 1939 and 1940, led Emmons to propose a revamping of their similalarly equipped counterparts in the U.S. Army Air Forces.

While Emmons’ proposed setup was adopted with some modification, it was relatively short-lived. By the beginning of 1943, “observation aviation”, as it was generically referred to, showed grave weaknesses during the North African campaign following the Operation Torch landings in Morocco and Algeria, so the whole USAAF observation program was overhauled once again.

The weapon-carrying bombers and fighters were deleted, the observation squadrons became reconnaissance squadrons equipped with unarmed photographic versions of high performance single and twin-engine aircraft, and a new type of light plane unit was born – the liaison squadron. Each of these new squadrons would eventually be equipped with thirty-two L-5’s apiece, with one squadron attached to each field army or army group. In the mean time, the Army won approval for its own light airplanes for artillery-spotting. Due to strong opposition from the Army Air Forces, their planes were limited to less than 100 horsepower by the War Department and and the docile Piper L-4 Cub became the favored choice.

Piper YO-59 at Wright Field. YO stood for service test, observation type. (AFHRA)

To sum up the importance of this date in October 1941, the two separate recommendations for the addition of light aircraft to the army ground and air force arsenals showed that the slow, vulnerable civilian-type planes had finally gained general acceptance among the “top brass” as a viable weapon of war. Ultimately, given their lilliputian stature compared to the fighters and bombers, and the small number procured compared to other types of aircraft , the little green “flivvers“, “puddle-jumpers”, “grasshoppers” and “flying jeeps” ended up making a disproportionately large contribution to success of the war effort. Not even the most vocal boosters of these simple, unarmed tube-and-fabric creations could have predicted their outstanding future success in combat.