Aircraft design, like any kind of technology, can be something of a hit-and-miss affair at times. But, when aircraft designers get it right, their designs can become legendary — like the P51 Mustang, Supermarine Spitfire, or the F-15 Eagle, to name but a few.
However, history is also full of forgotten and very unusual aircraft designs. Here are some of the most notable examples in history as well as some of our fond favorites.
This list is far from exhaustive and is in no particular order.
1. The Me P1109 might be the weirdest aircraft you have ever seen
Hands down, the Messerschmitt Me P1109 is probably the most interesting, if not strangest, aircraft designs of all time. One of the only known oblique-winged biplanes ever conceived, this aircraft never left the drawing board.
It was designed towards the end of the Second World War by German engineers to improve jet-engined aircraft performance at speed. Like other oblique-winged aircraft concepts, the ME 1109's unusual wings were designed to help reduce aerodynamic drag at high speed.
If ever realized, it would have been powered by twin jet engines. It is not known if a prototype was ever built, nor are there any existing records of it being wind tunnel tested.
2. The Dornier Aerodyne is very odd too
Basically, a giant flying cylindrical jet-engine, Alexander Lippisch's Aerodyne is another very weird aircraft design. Clearly, an engineer who liked to experiment with design, Lippisch was better known for his design of the Me 163 Komet (the world's first and only rocket-powered fighter),
Sometimes referred to as "the wingless uncrewed plane", this aircraft was effectively a large jet engine enclosed in a metal cylinder with a tail. The design, by all accounts, could have allowed the craft to fly at supersonic speeds.
What's more, engine exhausts were vented through a pair of vectored cascades that provided a propulsive lift for vertical takeoff, and downward/forward thrust when airborne.
The craft also came with a conventional tail unit that could, in theory, provide directional control in flight. The prototype was first flown in September of 1972, but the project was later abandoned.
3. The Blohm and Voss BV 141 was an interesting design
Looking like the product of someone trying to use up some spare aircraft parts, the Blohm and Voss BV 141 is like no other aircraft you have ever seen. A reminder that symmetry is not always essential when building an aircraft, the BV 141 was designed, and built, as a specialist reconnaissance aircraft.
Its main standout feature was the crew gondola on the aircraft's starboard wing, giving the aircraft its asymmetrical appearance. Here its crew of three (the pilot, observer, and gunner) would be housed.
Several dozen were built, but it would never enter full production and was abandoned in favor of the Focke-Wulf FW 189. Several wrecks were found by allied forces during the war, but none are known to have survived to the present day.
4. The McDonnell XF-85 "Goblin" really lived up to its namesake
A so-called "parasite" fighter, the McDonnell XF-85 was designed to be deployed from the bomb bay of a larger "host" Convair B-36 bomber. Devised just after the conclusion of WW2, the aircraft's diminutive form and features really mark it out as one of the strangest looking aircraft of all time.
The idea at the time was to have a series of fighter-carrying bombers deploy their fighter payloads whenever bomber groups came under attack. As conventional fighters would often struggle to match the range of bomber groups, the XF-85 was designed to help address this by only being deployed, and then recovered, when needed.
The project was canceled in 1949, as well as that of other "parasite fighters", in favor of developing mid-air refueling.
5. You've never seen anything like the Curtiss-Goupil Duck!
Designed as a steam-powered aircraft, the French-designed "Duck" is certainly a unique specimen. The brainchild of Alexandre Goupil in the 1880s, a replica was built by Glenn Curtiss in the late-1910s.
Goupil's designs indicated that the steam engine would power a single tractor propeller to the front of its rotund body. The pilot, and landing gear, would be attached via cables and frame underneath the body.
The body was, by all accounts, based on that of real birds, and an unpowered prototype was built and tested.
6. The Bartini Beriev VVA-14 was designed to hunt submarines
An interesting example of a VTOL amphibious aircraft, the Bartini Beriev VVA-14 wouldn't look out of place on a sci-fi film set. Developed by the Soviet Union in the early-1970s, this craft took advantage of the wing-in-ground-effect to cruise over water.
The VVA-14 was designed to be able to take off from the water and fly over long distances at very high speed. It could also skim above the sea surface as it hunted for enemy submarines.
It was designed by Robert Bartini, and two prototypes were built which flew over 100 test flights, although the VTOL system was not tested.
After the death of its designer, the project's development stalled and was eventually canceled in the late-1980s. The only known remaining VVA-14 now resides at the former Soviet Central Air Force Museum.
7. The SAAB 21 came with an ejector seat
Another very unusual lookıng aircraft is the SAAB 21. A single-seat, low-wing monoplane fighter, this aircraft is distinguishable by its characteristic twin-fuselage and rear-mounted "pusher" engine.
First flown in the early-1940s, the SAAB 21 was developed in preparation for Sweden potentially being drawn into WW2. It was powered by a Daimler-Benz DB 605B engine, and its particular engine configuration provided the pilot with excellent frontal visibility.
Unusually for aircraft of this period, the SAAB 21 also came with an ejector seat, to spare the pilot from hitting the rear propeller should they need to bail out. Entering service at the end of the war, it would serve for around 10 years before being replaced with more modern and capable jet-engined aircraft like the British de Havilland Vampire and SAAB 29.
8. Another off-looking aircraft is the Dornier Do 335
The Do 335, nicknamed the Pfeil ("Arrow"), was a Nazi heavy fighter built by the Dornier company during the Second World War. By far, its most prominent feature is its use of front and rear propellers in a push-pull configuration. It also featured an innovative ejector seat.
According to contemporary sources, one Do 335 was able to be flown at 474 mph (846 km/h) in level flight.
This aircraft's characteristic form helped reduce aerodynamic drag and it was the fastest German piston-engined aircraft during the war. Desperate to get the aircraft operational ASAP, delays in engine deliveries resulted in only a few ever being delivered by war's end.
It wasn't the prettiest aircraft ever built, but it is still a fond favorite of many aircraft enthusiasts today.
9. The Plymouth A-A-2004 is another very unusual aircraft
Taking advantage of something called the "Magnus Effect", the Plymouth A-A-2004 is very unconventional, to say the least. Based on similar planes called Flettner "Magnus Effect" planes, it used a series of spinning cylinders with circular endplates to generate lift using the principle of the "Magnus Effect", where asymmetrical spin generates additional lift.
Anton Flettner, the propulsion system's designer, believed that this setup could work well on aircraft wings, after successfully developing "Magnus Effect" sails for a ship.
Inspired by Flettner's recommendations, three anonymous inventors developed this particular aircraft in the 1930s. It was also reported to have made a series of successful flights over Long Island Sound.
Safety and reliability concerns about the aircraft would eventually lead to it being abandoned.
10. The Bleriot 125 was quite ambitious but was ultimately a failure
Another very peculiar aircraft was the Bleriot 125. Designed as an airliner, this very unconventional aircraft was first revealed at the 1930 Paris Salon de I'Aeronautique.
Primarily of wooden construction, the aircraft, in theory, had a top speed of 137 MPH (220 kM/h).
Passengers were to be carried in two oversized pontoons, or pods, that could accommodate 6 passengers each, including toilets and baggage compartments. These passenger pods were connected to the wings and tailplane on the port and starboard sides of the aircraft.
A central nacelle contained the crew compartment with front and rear-mounted push-and-pull configuration engines.
Only one prototype was built, and it performed very poorly during flight testing. Although attempts were made to improve its aerodynamics and performance, it would never receive the "green light" and enter production.
11. The Edgely Optica looks particularly ungainly
Another very unusual aircraft was the Edgley Optica. A British aircraft, the Optica was designed specifically to perform low-speed observation flights.
Ultimately intended as a low-cost alternative to helicopters, the Optica had a "loiter" speed of 8 mph (130 km/h) and a stall speed of 67 mph (108 km/h).
It was developed by John Edgley and first flew in the late-1970s. The aircraft was powered by a Lycoming IO-540 engine and entered limited production in the early-1980s.
Just over twenty were built, but an arson attack at the production facility destroyed ten of them. After years of changes in ownership, the Optica is back in the hands of its creator, who is seeking funding to bring it to full production.
12. Have you seen the Leduc 0.21?
Yet another unusual aircraft was the Leduc 0.21. A research aircraft built by the French in the 1950s might just be the inspiration for Thunderbird 1. With a top speed of Mach 0.87, it was powered by a specially designed Leduc ramjet capable of delivering 14,300 pounds of thrust (64 kN).
The purpose of the craft was to research the practicalities of ramjet technology, it built on the successes of its predecessor, the Leduc 1.0. Effectively a scaled-up version (around 30% larger), it was not capable of taking off under its own power and needed to be carried into the air by another aircraft.
Two working models were built and were successfully flight tested between the early to mid-1950s. Plans for a faster Mach 2 interceptor variant were developed, but never fully realized.
The Leduc series of ramjets (including the 0.21) was developed by Rene Leduc, produced by Breguet, and completed hundreds of test flights before being scrapped after governmental funding dried up.
13. Westland Pterodactyl IV looks like it is from another world
The final of the "Pterodactyl" series of sesquiplane (a type of biplane where one wing is significantly smaller than the other) developed by Westland-Hill, this aircraft is one of the strangest aircraft designs of all time. First appearing in the early 1930s, this two-seater fighter was powered by an enormous 600 hp (447 kW) Rolls Royce Goshawk engine.
Tailless, the aircraft's design compensated by having a large top-mounted wing that rose above the fuselage — giving the plane its strange "squatting" appearance. Incredibly, the aircraft was designed to have a rear-mounted electronically-operated twin-gun turret.
Test flights proved promising, but it never went into full production and was later canceled.
14. Scaled Composites Model 281 Proteus is another very strange aircraft
A tandem-winged high-altitude, low endurance aircraft, the Scaled Composites Model 281 Proteus is another weird-looking aircraft. It was designed by Burt Rutan to act as a platform for high-altitude telecommunications relays but has since been employed for various other uses.
The aircraft's design is incredibly efficient, and it can "orbit" at an altitude of over 55,000 feet (16,700 km) for more than 18 hours time. Currently, under the ownership of Northrop Grumman, only a single example was ever built.
The Proteus first flew in July of 1998 and has since been used for various research projects and missions around the world for organizations like NASA. It has a top speed of MACH 0.55 and can carry around 12,500 pounds (5,670 kg) of payload on takeoff.
It is also the holder of various world records for operation at altitude.
15. Meet one of the only jet-powered biplanes ever built
The PZL M-15 "Belphegor" is one of the world's only ever production jet-powered biplanes. Designed and built by the Polish air company WSK PZL-Meilec, it was often nicknamed the "Belphegor" (the noisy demon).
It was designed to fit the requirements of the Soviet Union, who were seeking to replace their aging Antonov An-2's, used for tending the vast wheat fields of Ukraine and Poland, and a vital food supply for the USSR. Part of this requirement, for some reason, was that the replacement aircraft should be jet-powered.
In response, WSK PZL-Mielec developed a prototype jet-powered biplane called the Lala-1. A little later, the first M-15 was developed and flew its maiden flight in 1973, but some serious issues were discovered with its handling, range, and operating costs.
However, its biplane form allowed the jet-powered plane to travel slower than any other jets without stalling.
Despite these issues, the aircraft went into production in the mid-1970s. Only around 175 were made, and production was finally halted in the early-1980s in favor of acquiring more "obsolete" An-2s instead.
16. The Vought XF5U "Flying Pancake" is also funny looking
Another very strange-looking aircraft is the Vought XF5U. Nicknamed the "Flying Pancake" or "Flying Flapjack", this experimental aircraft was designed by H. Zimmerman of the Chance Vought Division of United Aircraft Corp. in the late-1930s.
This company had supplied the U.S. Navy and Marine Corps. with many aircraft in the past, including the very capable and reliable F4U "Corsair".
Its unique, flattened, pseudo-disc-shaped body served to act as the aircraft's primary lifting surface, instead of wings. It was believed that by maintaining uniform airflow over the aircraft's entire wingspan, it should, in theory, be able to land at exceptionally low speeds, while maintaining great performance at speed too.
The XF5U was powered by two Pratt and Whitney WR-2000-2 radial engines buried within the body that drove a pair of propellers located on the leading edges of its "wingtips".
The aircraft had a top speed of around 452 mph (727 km/h) and was planned to be armed with six .50 machine guns. It could also, in theory, carry 2 1000 pound bombs and have four of its machine guns replaced with 20mm cannons.
Despite its impressive and innovative design, the aircraft would ultimately prove to be a failure. Budget constraints and a push for turboprops and jet-engined aircraft put the future of piston-engined aircraft, like the XF5U in question. Only 2 were ever built, and the project was canceled in 1947.
17. The Kyushu J7W "Shinden" would have been formidable in combat
And last, but by no means least, is the Kyushu J7W "Shinden". Meaning "Magnificent Lightning", this experimental Japanese WW2 fighter, is another very strange-looking aircraft.
Its main standout features are its rear-mounted wings, nose-mounted canard (winglets), and rear pusher engine setup. It was proposed as a short-range, land-based interceptor that, once in full production, would have been used to counter the threat of the USAF's Boeing B-29 Superfortress bombers.
During combat, it would have been armed with forward-firing 30 mm cannons fitted inside the nose. Its designers believed that the aircraft would have proved to be a highly maneuverable fighter, but it would never see active service.
Only two were built by the war's end, and the program was abandoned after the surrender of Japan in 1945.
And that is all for now folks.