Throughout history, the military never hesitated to pursue wild concepts. When innovation equals survival, engineers tend to play fast and loose with the line between brilliance and insanity. Some of these bizarre creations were ahead of their time, others were complete failures—but every one of them speaks to the power of human imagination to press the boundaries of what can be done in the skies. From wacky prototypes to breathtaking experiments, here are ten of the most bizarre military aircraft ever constructed.
10. The Christmas Bullet
If there is a trophy for worst plane ever constructed, the Christmas Bullet would take it hands down. Conceived in 1918 by Dr. William Whitney Christmas, a physician with no engineering background whatsoever, the Christmas Bullet was designed to conclude World War I by flying to Germany and abducting the Kaiser before returning in victory. The airplane design defied elementary aerodynamics: no wing struts, no bracing, only “flapping wings” like a bird. As one would expect, both prototypes crashed on their maiden flights, claiming the lives of their test pilots. The Bullet never entered service, but it did achieve immortal notoriety as aviation’s cautionary nightmare.
9. Curtiss-Wright XP-55 Ascender
The “Ass-Ender” nickname was given to this 1940s prototype for good reason. It inverted the fighter design on its head: pusher prop at the rear, canard wings upfront, and double tails—all in the name of improved maneuverability and visibility. Rather, it became a flying nightmare. The XP-55 constantly had stall issues and flight stability issues, resulting in crashes and an early demise. Fewer than three were constructed, but its strange appearance and reverse design continue to turn heads among aviation museums today.
8. Vought V-173 “Flying Pancake”
If you could see the V-173 flying overhead, you might think you were looking at a UFO. Designed during World War II by designer Charles Zimmerman, the “Flying Pancake” featured a flat disc-shaped body that acted as a single giant wing. Twin propellers assisted its takeoff almost vertically and landing on short runways. Test pilots described it as amazingly stable and dexterous, but the Navy dropped the project once jet engines became available. Despite this, the Pancake is still one of the most intriguing “what-if” projects of the time.
7. Northrop XP-79 “Flying Ram”
This plane was just what its nickname suggested—a flying ram. Conceived in 1945, it was designed to crash bodily into enemy bombers and destroy them. Constructed of magnesium and flying-wing shaped, it used raw speed and ruggedness to withstand ramming assaults. Sadly, its maiden flight resulted in a deadly crash, and the program was promptly canceled. The XP-79 never realized its ghoulish purpose, but it is still an eye-catching indication of wartime imagination carried to the limit.
6. Convair XFY Pogo
The Pogo resembled a rocket and flew like a rocket as well. Constructed during the 1950s, this vertical takeoff combat aircraft was intended to use tiny ship decks. With its mighty contra-rotating propellers, it could take off and land on its tail. In theory, it provided unparalleled versatility. In practice, it was frightening pilots—tail-first landings, while keeping your shoulder in the rear view was just about impossible. Although the idea didn’t work, the Pogo’s rocket-like posture is among aviation’s most unforgettable experiences.
5. Ryan X-13 Vertijet
If the Pogo was devious, the X-13 Vertijet was downright terrifying. This little jet could be vertically launched, hover, then switch to horizontal flight, and finally land by latching onto a recovery cable—nose leading straight up. It really did work, but it was so complicated and dangerous that it was never feasible. The Vertijet might have appeared ridiculous, but it contributed to the development of the VTOL aircraft of the present day, such as the Harrier and F-35B.
4. Horten Ho 229
Three decades before its time, the Horten Ho 229 was a streamlined German flying wing constructed at the close of World War II. It paired jet propulsion with a radar-bending shape, thus becoming the world’s first stealth-influenced aircraft. The Ho 229 was successfully flown several times before the close of the war, and its early design would go on to influence current stealth bombers like the B-2 Spirit. To this day, it appears to be something from the future.
3. Convair F2Y Sea Dart
A fighter that could land in the water? That was the vision that motivated the Convair Sea Dart. It used retractable hydro-skis to take off by skimming over the water and was the only seaplane ever to break the sound barrier in level flight. It was unstable and deadly to fly, however, and a fatal crash killed the program. Despite its flaws, the Sea Dart remains one of aviation’s boldest attempts at blending speed with versatility.
2. Rockwell HiMAT
During the late 1970s, the HiMAT (Highly Maneuverable Aircraft Technology) program took fighter capabilities to the ultimate extreme. Remotely controlled and designed for data gathering, this tiny experimental aircraft was capable of pulling maneuvers that no human pilot could survive. It experimented with new materials, aerodynamics, and control systems that impacted cutting-edge fighters such as the F-16 and F-22 directly. The HiMAT demonstrated that even unmanned prototypes could change the future of air-to-air combat.
1. Nord 1500 Griffon
Few planes appeared speedier when parked than France’s Nord 1500 Griffon. Produced during the 1950s, it used a turbojet for takeoff and a ramjet for scorching high-speed flight. With canard foreplanes and forward-swept wings, the Griffon II achieved more than 2,300 km/h on the test stand—a record-breaking achievement in its day. Although development stopped because of cost and complexity, the Griffon is one of the loveliest and most ambitious experimental jets ever constructed.
From flapping wings to water-skimming supersonic jets, these strange inventions remind us that flight innovation often starts with a nutty notion. Some were precursors to wonderful innovations, others disappeared into the dustbin of history—but all are testaments to the bold spirit of experimentation that continues to evolve flight.