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ERCO Ercoupe – The Worlds First Unspinable Aircraft

The ERCO Ercoupe is an American low-wing monoplane aircraft that was first flown in 1937. It was originally manufactured by the Engineering and Research Corporation (ERCO) shortly before World War II; several other manufacturers continued their production after the war. The final model, the Mooney M-10, first flew in 1968 and the last model year was 1970. It was designed to be the safest fixed-wing aircraft that aerospace engineering could provide at the time, and the type continues to enjoy a faithful following.

In 1931, aeronautical engineer Fred Weick was assistant chief of the aeronautics division of the National Advisory Committee for Aeronautics (NACA). In 1934 he asked permission to build an aircraft based on the 1931 Stout Skycar, using fabric instead of aluminium covering, and control modifications based on NACA research. Weick and a group of co-workers designed and assembled the experimental aircraft with a group of his colleagues who worked on the project in their spare time and paid for it themselves. The resulting aircraft, known as the W-1, featured tricycle landing gear, a parasol wing, and a pusher propeller configuration.

Fred Weick listed the W1 design goals that were tested in later seminars:

  • Tricycle landing gear with castering nosewheel, steerable if desired

  • Suitable longitudinal and lateral stability with limited up-elevator deflection, to prevent loss of control due to stalling and spinning

  • A glide-control flap

  • Two-control operation using controls for pitch and roll.

In 1934, the Bureau of Air Commerce approached Weick's team looking for standards for a competition for a safe and practical $700 aircraft. In 1936 the winner of the competition was the Stearman-Hammond Y-1, incorporating many of the safety features of the W-1. Two other winners were the Waterman Aeroplane and a roadable autogyro, the Autogiro Company of America AC-35. The W-1 was not intended for production to qualify as a competitor but was purchased by the Bureau for continued experimental tests in spin-control safety. After the prototype W-1 underwent a forced landing, an updated W-1A was built by Fairchild, incorporating leading-edge cuffs.

Weick left NACA in 1936 and joined Engineering and Research Corporation's (ERCO) fledgling aircraft team as chief designer, primarily to continue improving his aircraft design. Focusing his efforts on a number of design issues, primarily simplicity and safety, Weick strove to create a reasonably priced aircraft that would not stall or spin. Retaining the tricycle gear for ease of manoeuvring on the ground, and limited stall-spin features, Weick switched to a low-wing monoplane configuration in his new model, powered by an engine in tractor configuration.

The ERCO 310, which included a fully cowled engine, made its first flight in October 1937 at College Park Airport and was soon renamed the "Ercoupe". The easy-to-fly design included unique design features, including a large glazed canopy – with almost as much visibility as a bubble canopy – for improved visibility. The prototype 310 featured an ERCO-made inverted four-cylinder engine, the ERCO I-L 116, which was quickly dropped due to its high manufacturing cost compared to the new four-cylinder Continental A-65 air-cooled boxer engine. Lacking rudder pedals, the Ercoupe was flown using only the control wheel. A two-control system linked the rudder and aileron systems, which controlled yaw and roll, with the steerable nose wheel. The control wheel controlled the pitch and the steering of the aircraft, both on the ground and in the air, simplifying control and coordinated turning and eliminating the need for rudder pedals. A completely new category of pilot's license was created by the CAA for Ercoupe pilots who had never used a rudder pedal.

ERCO I-L 116

The Ercoupe was the first aircraft certified by the Civil Aeronautics Administration (CAA) as "characteristically incapable of spinning." The high-winged General Skyfarer obtained the second certification by licensing the ERCO technology. The first production Ercoupe, serial no. 1, NC15692 built in 1939 was donated to the National Air and Space Museum. In 1941 that aircraft, designated YO-55, was used in US Army Air Force testing.

The two-seat ERCO Ercoupe 415 went on sale in 1940. LIFE magazine described the aircraft as "nearly foolproof" and showed pictures of a pilot landing with his hands in the air. Only 112 aircraft were delivered before World War II intervened, halting all civil aircraft production. By mid-1941 aluminium supplies were being diverted to war-related production, so ERCO decided to manufacture Ercoupes for military use by using wood as the principal building material. The substitution of wood resulted in a heavier but quieter aircraft because the wood absorbed vibrations from the engine and airflow. Ercoupes were flown during the war by the Civilian Pilot Training Program for flight instruction, and the Civil Air Patrol used them to patrol for German submarines.

Although World War II had interrupted the production of the Ercoupe, general aviation manufacturers were enthusiastic about the prospects of a postwar aviation boom. Thousands of men and women were trained as pilots by the government, and the hope was that they would want to include flying in their civilian life. Production of the model 415-C resumed in 1945, and in 1946 alone 4,311 aircraft were produced and sold at a cost of US$2,665. This was the same price as in 1941. At its peak, ERCO was turning out 34 Ercoupes per day, operating three shifts per day. The aircraft was aggressively marketed through unconventional outlets such as the men's department of the Macy's department store chain.

However, private aircraft sales slumped after the war and the bottom dropped out of the civil aircraft market in late 1946, ending prospects for a booming market for civil aircraft sales. A 30-day lay-off at the factory in November resulted in rivets tossed around the factory and some aircraft sides and signs being painted. The year ended with an Ercoupe flown by a test pilot and mechanic breaking up in flight.

Aeronca obtained a licence to produce the Ercoupe 415 as the Aeronca 12AC Chum in 1946 and built two prototypes: NX39637, with the Ercoupe twin-tail, and NX83772 with a larger, single tail, metal wings and trailing-link struts in the main undercarriage. The Chum was powered by a Continental C-85J with a 108 mph cruise speed. However, no production ensued and the project once again went dormant.

In 1947 ERCO sold its remaining Ercoupe inventory to Sanders Aviation, which continued to produce the aircraft in the same ERCO-owned factory. A total of 213 aircraft were sold by 1950. During this time, ERCO's chief engineer Fred Wieck moved on to Texas A&M, where he developed the agricultural Piper Pawnee aircraft and eventually the popular Piper Cherokee with John Thorp and Karl Bergey.

Univair Aircraft Corporation of Aurora, Colorado purchased the Ercoupe design from the Engineering and Research Company in 1950. It provided spare parts and customer support to the existing aircraft.

In April 1955, Univair sold the Ercoupe-type certificate to the Forney Aircraft Company of Fort Collins, Colorado, which later became the Fornaire Aircraft Company. The aircraft produced differed from the 415-G in its engine/propeller combination they were upgraded to a C-90 engine, revised engine cowling, larger baggage compartment, and aluminium-covered wing panels. The F-1A model had three-axis controls and bucket seats. Production began in 1958 and ended in 1959.

Between August 1960 and March 1964, the rights to the Aircoupe aircraft were held by the AirCoupe division of Air Products Company of Carlsbad, New Mexico. The company was started by the city, with the hope of establishing aircraft manufacture as a local industry. It purchased the type certificate from Forney when a potential deal with Beechcraft fell through. Only a few airframes were produced before the type certificate was sold to Alon, Incorporated on March 16, 1964.

Alon Inc. was founded by John Allen and Lee O. Higdon, two executives who had retired from aircraft manufacturer Beechcraft to found their own company. They had previously negotiated with Forney Aircraft to purchase the production of the Aircoupe so that Beechcraft could use the design as an introductory trainer. The deal was cancelled by Olive Ann Beech, who decided to concentrate resources on the Beechcraft Musketeer. This decision caused the executives to leave Beechcraft and establish Alon in McPherson, Kansas, which purchased the type certificate for the Aircoupe from the City of Carlsbad, New Mexico on March 16, 1964.

The Alon A-2 and A-2A Aircoupes featured a sliding canopy, a Continental C90 90 hp engine, separate bucket seats and an improved instrument panel. The A-2 also differed from earlier two-control models in having limited-movement rudder pedals. This was done in order to make it a more acceptable training aircraft and to make it easier to counteract increased P-factor yaw during a climb from the more powerful engine. Nosewheel steering was no longer interlinked with the control yoke and was changed to the more common practice of being interlinked with the rudder pedals (this was the same system that was installed in the Forney F-1A). The older two-axis control system was offered as an option. The single-control (non-differential) wheel brakes remained. The aircraft had a higher rate of climb, a higher speed for the best climb rate, and better engine cooling. Its non-spinning characteristics remained unchanged.

Alon produced 245 A-2s from 1964 to 1967, with a peak production of 137 in 1966. The last 25 A-2s produced by Alon had spring-steel landing gear in place of the original main gear struts, light alloy castings and trailing links. The base price in 1967 was up to $7975. Production of the A-2 ceased in September 1967, and on October 9, 1967, Alon was purchased by and became a division of, the Mooney Airplane Company of Kerrville, Texas.

Mooney began producing the aircraft in 1968 as the Mooney A2-A. Next, the company redesigned the fuselage from the cockpit back, with square windows behind the sliding canopy. Even as it produced the A2-A Cadet, Mooney was busy re-designing the aircraft. On February 23, 1968, the first Mooney Cadet M-10 flew. The aircraft has a single fin, with a vertical leading edge, as most Mooneys do.

The type certificate was sold to Univair Aircraft Corporation of Aurora, Colorado in October 1974 and remains with Univair. The company has not produced any new aircraft but continues to produce replacement parts and provide technical assistance to Ercoupe owners.

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