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35-538: The General Aircraft Corporation was established to build an aircraft designed by Doctor Otto C. Koppen from the Massachusetts Institute of Technology . The aircraft was the G1-80 Skyfarer , a two-seat cabin high-wing braced monoplane with a light alloy basic structure and a mixed steel tube and fabric covering . It had an unusual tail unit, a cantilever tailplane with the elevator mounted on

70-726: A cost notably lower than that of competitive aircraft at that time. American Aviation built 459 examples of the AA-1 Yankee Clipper between 1969 and 1971 at their factory in Cleveland, Ohio. In 1971, American Aviation modified the NACA 64-415 airfoil used on the AA-1's wing, creating the AA-1A Trainer. The recontoured leading edge produced softer stall characteristics and permitted lower approach speeds. While this did tame

105-751: A major redesign of the AA-1B, resulting in the AA-1C. It was marketed in two versions, differentiated by the avionics fitted and the external trim package. The Lynx was targeted at private owners while the T-Cat was the flying school trainer. These names were chosen to position the aircraft in the Gulfstream American line which, at that time featured the Cheetah , Tiger and the Cougar . The AA-1C received

140-581: A need for a universal flight trainer more advanced than the analog Link Trainer . What started as the development of the Aircraft Stability and Control Analyzer (ASCA) for the Navy became "Project Whirlwind" . Headed by Captain Luis deFlorez , Otto Koppen, John R. Markham, and Joseph Bicknell put together the requirements for a simulator that factored in winds and aerodynamic forces. The byproduct that

175-445: A new larger horizontal tail and other significant improvements, including a 115 hp Lycoming O-235-L2C high-compression engine designed for 100LL fuel, which brought the cruise speed back up to that of the original 108 hp Yankee. 211 AA-1Cs were produced in 1977 and 1978. The last AA-1C was produced by Gulfstream American in 1978. Overall, 1820 AA-1 family aircraft were built between 1969 and 1978. The type certificate for

210-590: A short wing, with leading edge slats, with high lift and STOL capabilities. Greater Boston Metropolitan Airport fixed-base operator, E.W. Wiggins Airways converted the Piper PA-17 Vagabond with volunteer assistance to make the 2-place Helio No.1. Koppen also served as test pilot. This aircraft was the basis for the Helio Courier series of aircraft. The Helio Aircraft Corporation was formed in 1950 after merging with Midwest Aircraft Corporation,

245-576: A tilted gyroscope that sensed roll and yaw, to provide input to the autopilot. After his formal NACA report was published, his ability to file for a patent was nullified. In 1991 EAA Chapter 159 from Midland, Michigan , donated a replica Ford Flivver to the EAA Airventure Museum . The replica was built from careful inspection of the original prototype and advice from Otto C. Koppen. He lived in Osterville, Massachusetts . He won

280-598: Is now McDonnell Douglas ). Koppen, along with Harold Hicks and Tom Towle, are credited with refining the Stout -designed Ford 3-AT into the well known Ford Trimotor . In 1926, Koppen designed the Ford Flivver . As the first criterion for the design was that it had to fit in an office, his first task was measuring the dimensions of Ford's office. Koppen designed the Fairchild FT-1 in 1929. The aircraft

315-606: The General Skyfarer . Using just ailerons and elevators for directional control. 17 were built. The aircraft was later licensed as the Mars M1-80 Skycoupe, but did not go into production. In 1949, Koppen, and Lynn Bollinger formed the Helio Corporation of Massachusetts. They developed a "helioplane" prototype for a cost of 6000 dollars that was built based on a modified Piper Vagabond with

350-421: The elevator along with a centering spring system to increase longitudinal stability and stall strips to improve handling during a stall . The company designated the redesigned aircraft the AA-1 Yankee Clipper. The AA-1 was certified under FAR Part 23 on August 29, 1967, with the first production AA-1 flying on May 30, 1968. The first 1969 models were delivered in the fall of 1968 at a base price of US$ 6495,

385-452: The 1957 Godfrey L. Cabot Award . Otto Koppen died at the age of 90. Other pioneers of aircraft stability and control Grumman Yankee The Grumman American AA-1 series is a family of light, two-seat aircraft . The family includes the original American Aviation AA-1 Yankee and AA-1A Trainer along with the TR2. The TR2 has a cruise prop and the trainer has a climb prop. Typically

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420-526: The AA-1 entered a fully developed spin and exceeded three turns, it was usually not recoverable. The AA-1 had been spin-tested as part of its certification, but in 1973 the FAA issued Airworthiness Directive 73-13-07 ordering the aircraft placarded against spins. The remaining accidents were generally attributed to the AA-1's short endurance (3.3 hours), inability to use short grass strips and high approach speeds (85–90 mph). These were all different from

455-488: The AA-1 family of aircraft is currently held by True Flight Holdings LLC who bought the assets of Tiger Aircraft on August 2, 2007. All models of the AA-1 accommodate two people in side-by-side seating under a sliding canopy and are noted for their exceptionally light handling. The Yankee and its four-seater siblings, the AA-5 series, feature a unique bonded aluminum honeycomb fuselage and bonded wings that eliminate

490-490: The AA-1's sharp stall, it also reduced the cruise speed compared to the original AA-1 by 10 mph. First flight was on March 25, 1970, and 470 AA-1As were built in 1971–72. Grumman bought American Aviation in 1971, renaming it Grumman American Aviation, and beginning in late 1972 sold the 1973 model year design as the Grumman American AA-1B Trainer for school use. The variant designed for

525-500: The FAA was hesitant to certify a light aircraft with folding wings. The certification process was complex and expensive, and disagreements arose between Bede and the other shareholders. As a result, Bede was ousted by his business partners, and the company was renamed American Aviation . American's engineers reworked the wing to remove the folding feature, easing FAR Part 23 certification. Other changes included adding extended wing tips to improve rate-of-climb, an anti-servo tab on

560-556: The TR2 came with more navigation instruments and of course was better for cross country flying because of her speed and lower fuel consumption for equal distances The Grumman American AA-1B Trainer and TR-2 , plus the Gulfstream American AA-1C Lynx and T-Cat . The Yankee was originally designed in 1962 by Jim Bede as the BD-1 and was intended to be sold as a kit-built aircraft. Bede decided to certify

595-679: The United States became involved in the Second World War and the Skyfarer program was abandoned after either 17 or 18 examples had been built. At one point, a company called Tennessee Aircraft planned on manufacturing the airplane. However, the rights and tooling passed to Grand Rapids Industries, who built two aircraft before stopping production. The company became a manufacturer of the Waco CG-4A troop glider. The prototype

630-681: The age of eighty. At one point Koppen was the oldest instrument rated pilot in America. Koppen is regarded as providing the basis for most stability and control research since the 1930s. After a fire at the Stout Metal Airplane Division of the Ford Motor Company , which destroyed the Ford 3-AT Trimotor prototype, Tom Towle hired MIT graduate Otto Koppen, John Lee, and James Smith McDonnell (co-founder of what

665-629: The aircraft was sold by 1946. The aircraft, NC29030, resides in the Plymouth County, Iowa Historical Museum. General characteristics Performance Otto C. Koppen Otto C. Koppen (1901 – 1991) was an American aircraft engineer. Otto Koppen graduated with a Bachelor of Science from MIT in 1924. Koppen was the professor emeritus of aeronautical engineering at the Massachusetts Institute of Technology . In 1929 Koppen returned to teach stability and control at MIT, where he remained until his retirement in 1965. As part of

700-580: The company produced a variety of types for the Navy. The prototype aircraft "Helio-1" has been donated the National Air and Space Museum in 1963. Following the death of his daughter in an airplane crash in November 1950, Koppen took a two year break in teaching. Koppen developed a simplified autopilot that could be affordable enough to be used by general aviation aircraft. The bang-bang, or discontinuous, control device featured an innovative use of

735-662: The course, Koppen took students up in a Fairchild 24 to demonstrate stability principles. In 1936, Koppen published a paper called "SMART AIRPLANES FOR DUMB PILOTS". In 1939, a student brought a model of the new Curtiss XSB2C-1 to the MIT wind tunnel. Koppen was quoted as saying, "if they build more than one of these, they are crazy". He was referencing controlability issues with the small vertical tail. The eventual production aircraft did have issues, and needed over 880 modifications before entering combat in WWII. In 1944 America recognized

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770-519: The design under the then-new FAR Part 23 rules and offer it as a completed aircraft. No BD-1 kits were ever sold. The prototype first flew on July 11, 1963, and featured folding wings for trailering and ease of storage. Bede formed a company, Bede Aviation Corporation, based in Cleveland , Ohio , to produce the aircraft, but the BD-1 never entered production as a certified aircraft. At that time,

805-412: The design. For instance, because the flaps were the same part as the ailerons they were too small to be effective as flaps. The lack of wing washout, necessitated by the wing interchangeability requirement, meant that stall strips had to be installed to produce acceptable stall characteristics for certification. Over time this philosophy of compromising the aerodynamics in favour of a minimized parts count

840-403: The finished planes to the college. They then found local investors who formed Mars Corporation in 1945. The aircraft was later licensed as the Mars M1-80 Skycoupe with a 100 hp engine. One example was built and production plans were estimated to be as high as 75 planes in its first year. The glut of aircraft produced after the war left little market for the aircraft. The facility to manufacture

875-417: The need for rivets without sacrificing strength. The wide-track main landing gear struts are laminated fiberglass for shock absorption, marketed as the "Face Saver" design by American Aviation. The Yankee was originally designed to minimize the number of airframe parts used, with the aim of simplifying production and saving money. As a result of this philosophy, many parts were interchangeable. Due to

910-537: The other school aircraft in use in that era and took some adaptation by instructors and students alike. Today most of the AA-1s, AA-1As, Bs and Cs are in private hands. If the pilot is properly trained on the aircraft and stays within its limitations, data show that it is as safe as any other light aircraft. Some AA-1s have had their original engines replaced with larger 150 or 160 hp engines that further increase performance. Other popular modifications include

945-696: The personal-use market was called the TR-2 and it featured a standard radio and trim package. The AA-1B was produced until 1976. 680 AA-1Bs were produced. All the AA-1s, AA-1As and AA-1Bs were powered by the Lycoming O-235 -C2C low-compression engine designed for 80/87 avgas, which produced 108 hp. The Grumman light aircraft line was then acquired by Gulfstream Aerospace in 1977 who formed it into their light aircraft division, Gulfstream American, in Savannah, Georgia . That company division completed

980-476: The upper surface of the tail with aluminum endplate fins and no movable rudders. It was powered by a 75 hp (56 kW) Avco Lycoming GO-145-C2 geared air-cooled four-cylinder engine. The aircraft incorporated aerodynamic control principles covered by patents issued to Fred Weick , an early aeronautical engineer who went on to design and market the Ercoupe . Since it had no rudders (or rudder pedals), it

1015-409: The use of a non-tapered tubular spar, which doubled as the fuel tank, and the lack of wing washout , the wings could be exchanged left and right. The fin and horizontal stabilizers were interchangeable, as were the rudder and the elevators. The ailerons and flaps were similarly the same part. While it did succeed in making production easier, this design philosophy produced many aerodynamic compromises in

1050-529: Was abandoned. For example, the redesign of the AA-1B into the AA-1C by Gulfstream involved wider-span elevators and horizontal stabilizers that produced better longitudinal stability, but were no longer interchangeable with the rudder and fin. Powered by the same 108 hp Lycoming O-235 engine as the Cessna 152 , the original Yankee cruises twenty percent faster thanks to the cleaner wing and better aerodynamics . The original American Aviation AA-1 Yankee

1085-491: Was built in 1937 in a stable behind the General Aircraft Company president's house. In October 1944, a Skyfarer was used by Alverna Babbs, the first legless pilot to be granted a student pilot's permit, to complete her first solo flight at Lunken Airport . L.W. DuVon and Dr. David O. Kime of Western Union College convinced the type holder Grand Rapids Industries, to give the equipment, tools and one of

General Skyfarer - Misplaced Pages Continue

1120-455: Was designed to fill the role of a personal transportation and touring aircraft. Many of the early production models were purchased by flying schools. The appeal of the AA-1 to schools was obvious – compared to the competition, the AA-1 was faster, cost less to purchase and maintain and, most importantly, had more student-appeal with its sliding canopy and fighter-like looks. Many of the early school accidents were related to spin-training. Once

1155-476: Was developed to compute the data was one of America's first high-speed, prototypical, digital computer. Koppen took a two-year break from teaching after the loss of his daughter in a flight accident involving loss of control in low visibility conditions. Koppen promised his wife never to fly again afterward, but restarted after her death. Koppen flew a Grumman Yankee and experimented with wing-leveling and other controls. Koppen acquired his FAA instrument rating at

1190-419: Was simpler to fly (it had a single control wheel, which controlled the ailerons and elevator) , and was considered spin-proof . The aircraft was certified in 1941 with a placard that stated that the aircraft was characteristically incapable of spinning. It was claimed that an average person could learn to fly the Skyfarer in about an hour. It was anticipated that many aircraft would be ordered and built, but

1225-600: Was the model for the Fairchild Model 21 , a two-seat low-wing aircraft that bore a similarity to the Ford Flivver. Production was halted during the depression. In 1943 Koppen was brought on as an engineer to help design larger cargo aircraft for the Franklin Institute for 20,000 dollars a year. He was a designer for General Aircraft Corporation . Koppen designed an early two-control aircraft,

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