The Aeronca O-58/ L-3 Grasshopper was one of three models of commercial light aircraft that served as liaison and artillery spotter aircraft for the USAAF, filling a gap left by the slow development of the Stinson O-49/L-1 Vigilant
During the 1930s there was a great deal of debate about the sort of aircraft needed for the observation role, with a clear divide developing between the army liaison and reconnaissance tasks. Some argued that only a high speed aircraft similar to a light bomber could survive over the front line, while others wanted slow flying light aircraft, capable of operating from unimproved fields close to the front line. In 1939 the USAAC began a design contest for a ‘short range liaison observation’ aircraft, eventually selecting the Stinson O-49 as the winner. The events of 1940, where the Fieseler Storch was the most effective liaison aircraft on either side, demonstrated that the slow flying, short take off and landing aircraft was essential for artillery spotting and liaison duties in any war of movement.
The US Army Group Forces wanted to experiment with that type of aircraft during the 1941 manoeuvres, but the O-49 wasn’t ready for tests. Instead of waiting for the USAAF to provide the required aircraft, the Group Forces decided to rent a number of commercial aircraft for the Second Army’s June manoeuvres in Tennessee. At first Piper was the only company involved, but they decided to invited Aeronca and Taylor to take part as well, and each company provided four aircraft, which were rented out to the Army and flown by civilian pilots. Aeronca provided four of their Model 65 high winged monoplane
The light aircraft performed well in the summer manoeuvres of 1941. The Air Corps preferred the O-49, but that aircraft was much slower to build, and in November 1941 the General Staff suggested ordering 617 light aircraft. This was split between 342 O-57s, O-58s and O-59s and 275 Stinson model 76s, an improved version of an existing Stinson commercial aircraft. In January 1942 the ground forces held a conference at which they worked out they needed an impressive 4,000 aircraft! The Air Corps ordered another 1,000 aircraft, followed six months later by 1,960 more.
The Model 65 Defender and its military versions were built around a welded steel tube fuselage and tail structure, with a fabric covering. The wings used spruce spars, light alloy ribs and metal frame ailerons, again all fabric covered. It had a fixed undercarriage, with two struts for each of the main wheels. The two man cockpit was heavily glazed, with the wing supported on top of the canopy (the standard layout of all of these small liaison aircraft). It was powered by a 65hp Continental O-170 flat four engine. The original civilian version had trapezoid-shaped side windows in the rear position, ending roughly level with the wing trailing edge. This was the area that saw most change over the life of the L-3, with oval windows installed on the first production versions, later replaced with a more extensive glazed area.
By the end of December 1943 the USAAF and the Army Ground forces were operating 1,055 L-3s. However in an attempt to reduce the number of aircraft being produced, they were then classified as limited standard, and it was expected that no more would be ordered. A total of 306 L-2s and L-3s were produced during 1944, all from earlier contracts.
The L-3 was mainly used as home-based training aircraft. A handful did reach the combat area, but were normally soon replaced by the Piper L-4.
Aeronca continued to provide liaison aircraft after the war, producing the L-16 for the USAF.
The YO-58 designation was given to the four aircraft originally used by the Army trials. They were powered by the O-170-3 engine, and had quite a restricted rear view from the observer’s position, as the back of the cockpit was faired into the rear fuselage, the top of which was level with the wing. On the YO-56 the observer’s windows were angular in shape.
Fifty aircraft were ordered as the O-58 in 1942. They gained a military standard O-170-3 engine, and the observer’s side windows were made oval shaped.
Twenty aircraft were ordered as the O-58A. It was 4in wider, and had a modified observer’s window, in an attempt to improve the rear view.
335 aircraft were ordered as the O-58B. Another 540 were delivered as the L-3B after the designation changed in 1942. This version had a larger glazed cockpit area, which now extended well behind the wing trailing edge, and included a glazed roof, greatly improving visibility. They also carried more radio equipment. Take-off weight went up to 1,825lb, but top speed also rose, to 88mph.
490 L-3Cs were delivered, before production ended in 1944. They were identical to the L-3B, apart from not carrying any radio equipment.
L-3D/ E/ F/ G/ H/ J
These designations were given to civilian aircraft that were taken into military service after the American entry into the Second World War. The various designations reflected the type of engines installed. Eleven Model 65TFs became the L-3D. Twelve Model 65TCs became the L-3E. Ninenteen Model 65CA Super Chiefs became the L-3F. Four Model 65L Super Chiefs became the L-3G. One Model 65TL became the L-3H. One Model 65TC became the L-3K.
The TG-5 was a training glider based on the L-3. It used the same wings, tail and rear fuselage, with a new front fuselage, with room for three people but no engine. All three seats had similar flying controls, allowing for one tutor and two pupils. A total of 250 went to the USAAF as the TG-5 and three to the US Navy as the LNR.
Engine: Continental O-170 flat four piston engine
Span: 35ft 0in
Length: 21ft 0in
Height: 7ft 8in
Empty weight: 835lb
Maximum take-off weight: 1,300lb
Max speed: 87mph
Cruising speed: 46mph
Service ceiling: 10,000ft
Range: 200 miles