The ERCO 415 Ercoupe was a response to the Bureau of Air Commerce's sponsored design competition during the mid-1930s for an easy-to-fly, safe airplane. Designed by Fred Weick and his fellow engineers at the National Advisory Committee for Aeronautics (NACA) Research Laboratory in Langley, Virginia, the Ercoupe received attention as the first tricycle gear all-metal light airplane that demonstrated spin and stall proof characteristics, and additional features made the aircraft truly safe for the low-time pilot. Capable of operations into and out of small airfields, it was inexpensive to purchase and operate.

Several companies built nearly 6,000 Ercoupes or some variant over nearly three decades. This Ercoupe 415C was manufactured in October 1939 as the first production 415C built. This aircraft was initially used for flight training, but in early 1941 was briefly evaluated by the US Army Air Forces at Fort Sill, Oklahoma, for observation or target drone roles and given the temporary designation YO-55. After being returned to civilian use that same year, it was donated to the Museum in 1979.

The Ercoupe 415 two-place light airplane was a response to the Bureau of Air Commerce sponsored design competition during the mid-1930s for an easy-to-fly, safe airplane. While working at the National Advisory Committee for Aeronautics (NACA) Research Laboratory in Langley, Virginia, Fred Weick and several of his fellow engineers decided to design an airplane to fulfill the requirements set forth by Bureau Director Eugene Vidal. The resulting Ercoupe was easy to fly and spin proof with no dangerous stall characteristics, and a good field of view. It was capable of operations into and out of small airfields, was financially within reach of a large section of the public, and was inexpensive to operate and maintain.

Weick built his first aircraft, the W-1 and W-1A for this competition as simplistic proof of principal experimental test models that encompassed many of the design features that were to be built into the production prototype. These airplanes were fabric-covered, high-wing, twin-boom pushers which had a tricycle landing gear with a steerable nose wheel. During the design and testing of these airplanes the Engineering and Research Corporation (ERCO) was founded in Riverdale, Maryland, to carry on the design which became the Ercoupe 415 airplane. Henry A. Berliner was ERCO's president and Weick was the chief designer.

Weick designed a two-place, low-wing monoplane that utilized a two-control system, linking the rudder and aileron controls systems (yaw and roll) with the steerable nose wheel, via a control wheel. The wheel controlled the elevator (pitch) and the steering of the airplane both on the ground and in the air, thus eliminating the need for rudder pedals. With no rudder pedals or stick, the aircraft took on automobile characteristics including a brake on the floor.

The Ercoupe received attention because it was the first tricycle gear all-metal (duralumin) light airplane that demonstrated spin and stall proof characteristics. The differential movement of the ailerons countered adverse yaw and rudder action in conjunction with the aileron movement. The aircraft had twin fins and rudders that were positioned outside the propeller slipstream. The elevator/pitch control surfaces were limited to 12 degrees of upward travel to limit the pitch up and thus maintain the benign stall that, at its worst, was a gradual loss of altitude in the power-off condition. Landing requirements in a cross wind called for the unusual procedure of keeping the aircraft into a crab all the way down to the runway, because castoring wheels and the steerable nose wheel could align with the runway on impact. Again, this was done to simplify landing techniques and reduce potential accidents.

These features made the aircraft a truly safe airplane for the low-time pilot, who could solo more quickly and benefit from lower insurance premiums. However, because of the aircraft's inability to spin, Ercoupe pilots were at first prohibited from flying other aircraft because they had not received spin training. Because many experienced pilots were confused by the lack of rudder pedals, later production Ercoupes offered a rudder bar. Pilots also regretted the loss of the ability to slip the plane on approach (to lose altitude rapidly) because of the counter adverse yaw characteristics of the aircraft. Flying the Ercoupe is a different experience, but it is one that many pilots enjoy to this day.

In pre-war production, 112 415Cs were built with the 65 hp engine. The design was then converted to the D model that had the 85 hp Continental engine installed. This production was done principally after World War II. Several companies built nearly 6,000 Ercoupes or their variants over a period of nearly 30 years. In 1955, Forney Manufacturing Company produced the type certificate as the Forney F- I Aircoupe, and it was later manufactured by the Air Products Company of Carlsbad, New Mexico, until 1962. In 1963 Alon Inc. of Wichita, Kansas, bought the rights to the airplane and put it back into production in 1964 with a 90 hp Continental engine. In 1967 Alon merged with Mooney Aircraft of Kerrville, Texas which redesigned it with a distinctive Mooney single tail and renamed it the Mooney M-10 Cadet. Mooney built only a few of this model and then sold the rights to Aerostar Aircraft Corporation in 1970 where the M-10 became the Aerostar 90. The line ended in 1970.

Ercoupe 415C, NC15692, the first production 415C built, was manufactured in October 1939 and received its FAA airworthiness certificate on April 2, 1940. The airplane was first sold in January 1941 to the Brinkerhoff Flying Service at College Park, Maryland, where it was used for flight training. From there it went through a succession of owners until it was acquired by Robert Whipperman of Harbor City, California, in January 1946, who owned also two others. In early 1941, this aircraft was evaluated by the US Army Air Forces at Fort Sill, Oklahoma for observation or target drone roles and was given the temporary designation YO-55 before it returned to civilian use later that year. Whipperman donated the airplane to the Museum in 1979 as an example of an early and unique civil airplane design that pioneered the use of practical safe airplane technologies. The airplane arrived at the Paul Garber Restoration and Storage Facility in Suitland, Maryland in June 1979.