Building a single aircraft design is accompanied by huge financial backing for research and development and a lot of time and human effort before it is completed to be test flown, but for some reasons a number of history’s novel aircraft built were short of the expectations and never hit the prospected market.
Nicknamed “The Spruce Goose” it was built as a prototype of a heavy transport aircraft designed and built by the Hughes Aircraft company. It was built on wood due to the the scarcity of aluminum prioritized on fighter aircrafts during the war. The aircraft was never built in time to serve its purpose but was somehow continued to be built in airworthy condition by Howard Hughes who flew it once in November 1947 until it was finally preserved in good condition at Evergreen Aviation Museum in Oregon. The aircraft still holds the record as the largest flying boat ever built with the largest wingspan and height of any aircraft in history.
The Northrop XP-79 was considered an ambitious design for a flying wing fighter aircraft. It was originally designed as a rocket powered interceptor but the malfunction of both engines in tests led it to be replaced by turbojet engines. The feature of this aircraft has the pilot in prone position to withstand greater G-forces. With only one built, it was retired after its test flight in 1945.
The De Havilland Comet came to be known as the world’s first commercial jet airliner and came to service in 1949 . A series of accidents though hampered its airline function and ultimately started aircraft accident investigations which provided data for the design of stronger, safer commercial jet airliners that we knew today.
The Northrop YB-49 was a prototype jet-powered flying wing bomber developed for the US Air Force after World War II. It was actually a modified YB-35 whose piston engines were replaced by more powerful jet engines. Out of two built, one figured in a crash and the other caught fire while taxiing. The program was cancelled in 1950 in favour of a more conventional Convair B-36 and later the B-52 Stratofortress.
The Douglas X-3 was US Air Force/NACAs funded experimental jet research aircraft in the 1950s with a slender fuselage and long tapered nose aimed at attaining sustained supersonic speeds. Its design features the first use of titanium in major airframe components. The design however was a failure since it was underpowered and couldn’t even exceed Mach 1 in level flight. With its last flight in 1956, it was finally retired and with only 1 built out of two authorized for production, it became a museum piece at the US Air Force Museum. The data gained at the research however showed the dangers of roll inertia coupling and the wing design was adapted in the F-104 Starfighter.
The North American XB-70A Valkyrie was a prototype for a proposed B-70 nuclear armed deep penetration bomber for the USAF’s Strategic Command. It was designed in the 1950s but took the air late in 1964. It was a large aircraft built for speed to avoid enemy detection powered with 6 jet engines. It was capable of attainining Mach 3 at high altitude but owing to low fuel efficiency of engines during the period of its inception, bomb payload needs to be sacrificed for fuel payload in order for it to deliver its cargo to the desired destination. With the emergence of anti aircraft missiles, the program was cancelled in 1961 and following one mid air collision that took 1 aircraft in 1966, only 1 remained on display at the Naitonal Museum of the USAF in Ohio.
With the first prototype flown in December 1968 the Tupolev Tu-144 (NATO Codename: Charger) was the world’s first supersonic transport aircraft even preceding the Concorde (1969). Certain design issues however failed to be addressed added by the Paris Air Show crash in 1973 and a succeeding crash in 1978 pending fielding to airline service placed the aircraft development to a halt.
The Lear Fan 2100 Futura was Bill Lear’s final design for a twin-engined pusher propjet made entirely from composite materials. Out of the three prototypes only one flew its maiden flight in January of 1981 and was retired for museum display.
The Beech Starship started out as a replacement for Beechcraft King Air 200 series of turboprop executive transport. First full scale prototype flew in February 1986 but considering the employment of composite materials which at that time was mainly utilized in military aircrafts certain delays emanated. Flight handling characteristics proved unstable as well with the nose having the tendency to pitch up and to droop down in level flight coupled with extreme noise developed with the wings’s vortices mixed up with the wing- mounted propellers in pusher configuration. Out of 53 built only few had been sold and no further orders followed considering price and performance comparisons with existing aircraft within the category. The sad consequence led to the scrapping of the rest of the aircraft type in Pinal Airpark, Arizona where all grounded aircraft were left to retire leaving only 6 in airworthy status.
The Sikorsky/Boeing RAH-66 Comanche was one of the contenders for the US Army’s requirement to replace the UH-1(Bell,Huey), AH-1(Bell,Cobra), OH-6(Hughes,Cayuse) and OH-58 (Bell,Kiowa Warrior) under the Light Helicopter Experimental (LHX) program. It eventually won the bid for the program with the first prototype flown in January 1996. The RAH-66 Comanche features an all composite fuselage with radar absorbent materials, a fully integrated digital flight controls and advanced navigation and weapons systems. Designed as a twin-turbine, two-seat (tandem) armed reconnaissance helicopter with projected missions for armed recon, light attack and air combat it does a multi-role mission as addressed by the previous types of helicopters it was supposed to replace. Furthermore, it utilizes an anti-torque system unlike the conventional tail rotors in the form of a Fantail anti-torque system much similar to the Fenestron anti-torque system employed by helicopters made by Eurocopter. This design has proven less tail strike encounters and less noise. The fate of this sophisticated piece of flying equipment met a hard landing though. Budget cuts coupled with the complex structure of its stealth characteristics and the successful evaluation of fielded Unmanned Aerial Vehicles(UAVs) in Afghanistan resulted to the cancellation of the funding for the mass production. (I suppose there was a similar UAV based on the data gained from the research produced).