<p>In 1941 the US Army conducted an operational evaluation with four of each of three types of two-seat light aircraft for use in the artillery spotting and liaison roles, the three types being the Taylorcraft YO-57, the Aeronca YO-58 and the Piper YO-59; all were known as Grasshoppers. The successful use of the aircraft during the US Army's maneuvers, operating directly with ground forces, resulted in increased production contracts for all three, although the Piper design was to be the most prolific.
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<p>The first four Taylorcraft YO-57s were standard civil Taylorcraft Model Ds, powered by the 65-hp (48-kW) Continental YO-170-3 flat-four engine, and were followed by 70 basically-similar O-57s. However, the need to provide all-round vision resulted in modifications to the cabin and rear fuselage and the introduction of trailing-edge cut-outs at the wingroots. Other alterations to fit the aircraft for its specialized tasks included an observer's seat which could be turned around to face the rear, and the installation of radio. In this form the type was designated O-57A and 336 were manufactured.
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<p>A further 140 were built under the designation L-2A, US Army aircraft of this class having been reclassified from observation to liaison in 1942. The YO-57s and O-57s became L-2s and the YO-57As were redesignated L-2A. Some 490 aircraft with special equipment, built for service with the field artillery, were designated L-2B and the final variant, with a production run of 900, was the L-2M, identified by the fully cowled engine and the fitting of wing spoilers.
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<p>Taylorcraft aircraft were also involved in the training program for military glider pilots, involving 43 impressed civil machines which were used to provide an initial powered flying course. This total of 43 comprised nine Model DC-65s and nine BC-12-65s, both with Continental A-65 engines and designated L-2C and L-2H, respectively; one DL-65, seven BL-65s and four BL-12-65s, with Lycoming O-145s and designated L-2D, L-2F and L-2J; and seven DF-65s, two BFT-65s, three BF-12-65s and one BF-50, all with Franklin 4AC-150s and designated L-2E, L-2G, L-2K and L-2L. The company also developed a light training glider version which was known as the Taylorcraft ST-100 and given the designation TG-6. The front fuselage was extended and a 'glasshouse' canopy fitted, the landing gear simplified and a skid added under the nose; the lengthened nose necessitated increased fin area. Production totalled 253, including three for US Navy trials.
<item><hi format=bold>Powerplant:</hi> one 65-hp (48-kW) Continental O-170-3 flat-four piston engine
<item><hi format=bold>Performance:</hi> maximum speed 88 mph (142 km/h); service ceiling 10,000 ft (3,050 m); range 230 miles (370 km)
<item><hi format=bold>Weights:</hi> empty 875 lb (397 kg); maximum take-off 1,300 lb (590 kg)
<item><hi format=bold>Dimensions:</hi> span 35 ft 5 in (10.79 m); length 22 ft 9 in (6.93 m); height 8 ft 0 in (2.44 m); wing area 181 sq ft (16.81 m<su>2</su>)
