The world of military aviation has seen its fair share of innovative and unconventional fighter jet designs. Over the years, various nations have embarked on ambitious projects to create fighter aircraft with unique features and capabilities. From strange-looking designs to experimental technologies, these fighter jets stand out as some of the weirdest and most intriguing in history.
For our purposes here, the sole requirement is the sheer peculiarity of the plane’s design – the more unconventional it is, the better. Fighter jets are specifically crafted as jet aircraft intended for aerial combat against other aircraft.
The whole list consists of designs that never went into mass production and never were adopted (with one exception).
Now join us as we explore the Top 10 oddest fighter jets ever produced, counting down from 10th place and working our way up to the top spot.
Honorable mention: Saab J35 Draken
It doesn’t make our Top 10, and the Saab J35 Draken was not as unconventional in appearance as some others on this list, but it did have a unique double-delta wing design. The forward-swept wing and the delta-shaped tail gave it an unmistakable silhouette. The Draken’s innovative design allowed for high agility and remarkable performance during its service with the Swedish Air Force.
The first flight of the Saab J35 Draken took place on October 25, 1955, and it was retired from military service in 2005. However, at least two aircraft continue to operate in the Swedish Air Force Historic Flight association.
10. Nord 1500 Griffon
The Nord 1500 Griffon, also known as the ‘Nord 1500-01 Griffon’, is an aircraft that stands out for its unusual and distinct design. Its first flight took place on September 20th, 1955, and it was designed by Nord Aviation, a French aerospace company, with the intention of exploring various unconventional aerodynamic concepts.
One of the key features that made the Nord 1500 Griffon so unusual was its unique configuration. It had a canard layout, which meant that it featured small wings at the front of the aircraft, positioned ahead of the main wing. This design was relatively uncommon at the time, and it gave the Griffon a distinct appearance compared to traditional aircraft configurations.
Moreover, the Nord 1500 Griffon was equipped with a forward-swept wing, which was another unusual characteristic. Forward-swept wings are known to have some advantages, such as improved maneuverability and stall resistance, but they also present challenges in terms of structural integrity and stability.
The Griffon II used mixed turbojet and ramjet propulsion. The turbojet would allow the fighter to take off while the ramjet would take it to its top speed. On October 5, 1959, the plane set a speed record of 2,320 kilometres per hour (1,440 miles per hour).
Despite its intriguing design, the Nord 1500 Griffon faced a series of developmental issues and it never progressed beyond the prototype stage. It underwent several modifications in an attempt to address the challenges posed by its ramjet propulsion and the heat it generated. However, the project was eventually abandoned, and no production versions of the Griffon were ever built.
9. Northrop XP-79 Flying Ram
The Northrop XP-79 was an experimental jet developed during World War II in 1945 with a highly unconventional and audacious purpose. It was designed as a ’flying ram’, essentially serving as a manned missile with the main objective of physically colliding with enemy aircraft in mid-air.
The XP-79’s development was motivated by the belief that enemy bomber fleets posed a significant threat and conventional interceptors might not be able to effectively counter them. The idea was that a fast and agile manned aircraft like the XP-79 could be flown into enemy formations, engaging in direct and destructive collisions to take down enemy bombers. That concept was eventually abandoned, but the XP-79 program continued to develop a more conventional interceptor.
Before the XP-79 could prove its worth or the validity of its concept, it faced a disastrous incident during its initial test flight on September 12, 1945. The aircraft experienced stability issues, leading to a crash that tragically claimed the life of its test pilot, Harry Crosby.
The fatal accident, along with the changing military strategy and advancements in conventional interceptors, led to the discontinuation of the XP-79 program.
8. Vought V-173 Flying Pancake
The Vought V-173 was an extraordinary experimental fighter aircraft. Its unique and distinct design featured a disc-shaped airframe, earning it the nickname ‘Flying Pancake’. The unconventional shape was intended to explore the potential benefits of improved lift and maneuverability.
The aircraft’s disc-shaped wing and fuselage design were the most striking aspects of the V-173. The circular wing, with a diameter of 23 feet (7 meters), incorporated a series of flat panels that formed the pancake-like structure. The circular wing had a greater chord (width from front to back) than conventional wings, which allowed for a larger lifting surface without significantly increasing the aircraft’s overall size.
The V-173 first took to the skies on November 23, 1942, in a series of test flights piloted by Boone T. Guyton. During the test program, the aircraft demonstrated impressive low-speed performance and excellent maneuverability. However, the V-173’s top speed was relatively modest, limiting its potential as a high-speed fighter.
Though the V-173 showed promise and it had several successful flights, it did not progress to full-scale production or widespread adoption. Its design principles were integrated into a more advanced version known as the Vought XF5U-1, featuring a larger twin-disc airframe. But by the time a prototype was ready for testing, the need for such unconventional aircraft had diminished, as more conventional fighter designs had advanced significantly during the war.
7. Convair XFY Pogo
The Convair XFY Pogo, a product of the innovative 1950s era, captured the imagination with its distinctive “tailsitter” design and promising vertical takeoff and landing (VTOL) capabilities. It took its first tethered flight on April 19, 1954.
The aircraft’s appearance was undeniably unconventional, boasting a single-seat cockpit perched vertically atop a slender fuselage. Another notable feature was the unique arrangement of contra-rotating propellers, which enabled it to achieve vertical flight.
Developed specifically for the United States Navy, the XFY Pogo was intended to address the need for fighter aircraft capable of operating from smaller decks of aircraft carriers or even helipads. The VTOL concept had the potential to revolutionize naval aviation, offering greater flexibility and adaptability in a variety of scenarios.
However, despite its futuristic concept, the XFY Pogo faced significant challenges that hindered its practical viability. One of the most notable hurdles was related to stability and control during vertical flight operations. The aircraft struggled to maintain a steady hover, and this instability proved to be a critical issue during the testing phase.
Therefore, despite numerous efforts to refine and enhance its design, the XFY Pogo project faced increasing setbacks. Eventually, it became apparent that the technical challenges were too overwhelming to resolve within a reasonable timeframe, and the U.S. Navy decided to cancel the program.
6. Yakovlev Yak-38U
The Yakovlev Yak-38U, the twin-seat version of the VTOL fighter jet Yak-38 has an intriguing history that reflects the tumultuous era of Soviet aviation experimentation. Its design and appearance were indeed distinctive and often likened to a curious amalgamation of various elements from different aircraft. It is the only aircraft in this list that actually entered service.
The Yak-38 was developed during the 1970s as part of the Soviet Union’s ambitious efforts to create viable VTOL aircraft for their naval aviation. Inspired by the success of the British Harrier jump jet, Soviet engineers sought to create a similar aircraft that could operate from the decks of aircraft carriers and small naval vessels, providing greater flexibility in combat scenarios. On January 15, 1971, it took flight for the first time.
While the Yak-38U shared some design similarities with the Yak-38, it was equipped with a larger cockpit to accommodate a second seat for a co-pilot or instructor, offering training capabilities.
The VTOL technology used in the Yak-38 was novel, involving the deployment of swiveling nozzles that directed the exhaust gases downward for vertical takeoffs and landings. Unlike the Harrier, which was entirely powered by a single engine, the Yak-38 made use of two smaller engines for vertical lift. However, the aircraft’s complex mechanical systems and design compromises resulted in numerous challenges.
Like its single-seat counterpart, the Yak-38U faced issues with performance, limited payload capacity and a relatively short operational range, which hindered its combat effectiveness. The Soviet Navy experienced operational difficulties with it and was not satisfied with the aircraft’s capabilities, leading to an infamous reputation.
With advancements in fixed-wing naval aviation and the development of more capable fighter aircraft, the Yak-38’s role slowly diminished, and the aircraft gradually retired from service in 1991.
5. Rockwell HiMAT
The Rockwell HiMAT (Highly Maneuverable Aircraft Technology) was an experimental remotely piloted aircraft developed by Rockwell International in the late 1970s and early 1980s. Taking its first flight on July 27, 1979, it was designed to explore and demonstrate advanced aerodynamic concepts and flight control technologies.
The HiMAT was an agile and futuristic-looking aircraft with a delta wing configuration. Its purpose was to investigate various cutting-edge technologies and material that could potentially be used in future fighter aircraft, with the aim of enhancing their maneuverability, survivability and overall performance.
During its flight-testing phase, the HiMAT showcased remarkable agility and maneuvering capabilities, sustaining 8G turns at near supersonic speed. The aircraft’s performance, and the data collected during its flights, contributed significantly to the advancement of several follow-on programs.
However, despite its early promise, the HiMAT program was brought to an end. The use of a remote-controlled aircraft was deemed too complex, with up to five pilots needed during each flight test for various roles. The aircraft was used for a series of flight tests and research missions, but it was not intended for production or operational deployment and was retired in January 1989.
4. Horten Ho 229
The Horten Ho 229, also known as the Gotha Go 229, was a groundbreaking prototype fighter jet designed during World War II. The aircraft’s flying wing configuration was ahead of its time, and its innovative design elements made it a fascinating subject of study for aviation engineers and historians.
The Ho 229 was the brainchild of brothers Walter and Reimar Horten, who were German aircraft designers with a vision for a radical new approach to aviation. Their concept of the flying wing involved eliminating the traditional fuselage and tail section and integrating all essential components, including the cockpit and engines, into the wing structure itself. This approach resulted in a streamlined, tailless aircraft, offering reduced drag and increased efficiency when compared to conventional designs.
On February 2, 1945, the Horten Ho 229 made its first flight, piloted by test pilot Erwin Ziller. The aircraft’s maiden voyage was conducted at Oranienburg, Germany. The flight was reportedly successful, demonstrating the potential of the flying wing design. The Ho 229 showcased impressive performance, and its unique shape provided it with a reduced radar cross-section, unintentionally foreshadowing the principles of modern stealth technology.
However, despite its promising performance, Ho 229’s development faced numerous challenges and obstacles due to the chaotic conditions of the final stages of the Second World War and the German war effort’s increasing difficulties. The project suffered from material shortages, limited resources, and the constant threat of Allied bombing raids, which ultimately derailed the development process.
The Horten Ho 229 program was never able to fulfill its intended role as an operational fighter jet during the war. The aircraft’s development was halted due to the collapse of Nazi Germany, and only a few prototypes were built. Following the war’s end, the Allies captured the remaining Ho 229 prototypes, and the technology was studied and analyzed to gain insights into the innovative design.
3. Ryan X-13 Vertijet
The Ryan X-13 Vertijet was an ambitious VTOL aircraft developed by Ryan Aeronautical Corporation in the 1950s, as part of the United States’ efforts to explore advanced aviation technologies. The aircraft’s primary goal was to demonstrate the feasibility of vertical flight and the viability of transitioning from vertical to horizontal flight seamlessly, with the hopes to eventually develop a submarine-borne aircraft.
On December 10, 1955, the X-13 Vertijet achieved its first successful flight at Edwards Air Force Base in California, marking a significant milestone in the history of VTOL aviation. The aircraft’s maiden flight was a moment of anticipation and excitement, as it aimed to prove that it could overcome the challenges associated with vertical takeoffs and landings.
The X-13 Vertijet featured a unique design, including a ball-mounted nozzle that could redirect exhaust gasses in the direction needed, allowing the aircraft to transition between the two flight modes. This transition was a critical and demanding phase of the flight, as it required precise control and stability.
During the testing phase, the X-13 Vertijet demonstrated the envisioned smooth transition between vertical and horizontal flight, validating the effectiveness of its innovative propulsion design. However, the vertical landings proved more difficult, making the recovery of the aircraft a complex operation, and the development was becoming costly.
Due to these challenges and the availability of more practical alternatives, the interest in tailsitter aircraft diminished over time, and other VTOL aircraft designs became more prevalent. Therefore, Vertijet retired on September 30, 1957.
2. Curtiss-Wright XP-55 Ascender
The Curtiss-Wright XP-55 Ascender was a unique and experimental fighter aircraft that entered development during the Second World War. The aircraft’s design departed significantly from conventional fighter planes of its era, featuring a distinctive canard configuration and a pusher-propeller layout.
The XP-55 Ascender’s first flight took place on July 19, 1943, with test pilot J. Harvey Gray at the controls. During its testing phase, the XP-55 Ascender demonstrated satisfactory stability, however when testing for stall performance at altitude in November 1943, the XP-55 was lost due to uncontrolled descent.
Also, the XP-55 Ascender struggled to surpass the performance of other contemporary fighter planes, and its top speed and rate of climb were underwhelming when compared to standard front-line fighters like the P-51 Mustang or the P-47 Thunderbolt. Additionally, the pusher-propeller configuration led to some issues with engine cooling, affecting its overall performance.
As the war continued, advancements in jet engines rendered some of the XP-55’s limited benefits obsolete.As a result, only three prototypes of the XP-55 Ascender were built, and no production units were ordered. The project was canceled in 1944, and the two existing prototypes were relegated to test and evaluation purposes.
Top 1- Convair F2Y Sea Dart
The Convair F2Y Sea Dart claims the top spot on our list as the world’s weirdest fighter jet ever built.
It was a fascinating and ambitious experimental aircraft developed during the 1950s by Convair, a prominent American aerospace company, in an attempt to create a high-speed, supersonic seaplane fighter jet, a concept that had not been explored extensively until that time.
The F2Y Sea Dart’s first flight took place on January 14, 1953, piloted by test pilot Charles E. Richbourg. The aircraft featured a unique design with twin hydro-skis, enabling it to take off from and land on water. This ability made it an interesting candidate for naval operations, as it could potentially operate from bodies of water, including oceans, rivers, and lakes, forgoing the need for a runway.
The F2Y Sea Dart program faced challenges that ultimately limited its operational potential. The aircraft encountered difficulties with its hydro-skis during takeoff and landing, which impacted its overall effectiveness as a seaplane fighter. Additionally, the complexity of operating a high-speed aircraft from water posed significant operational and maintenance challenges.
In a tragic accident on November 4, 1954, test pilot Charles E. Richbourg lost his life during the midair disintegration of the Sea Dart he was piloting. Ultimately this, coupled with a whole series of disappointing outcomes, caused the program to be terminated. The remaining four planes were retired in 1957, although a few were kept in reserve until 1962.