Military aviation has always been a field for bold experimentation—now and then visionary, sometimes downright bizarre. When hostilities erupt and innovation is a matter of utmost urgency, engineers and air forces have been prone to experiment against sound reason. Some of these planes crashed in spectacular failure, others limped along to modest success, and a few pushed technology in unpredictable ways. Here’s a look at ten of the strangest military planes ever built, from “surprisingly useful” to “what were they thinking?”
10. The Christmas Bullet
If there were a prize for worst plane ever, the Christmas Bullet would be the winner. Constructed in 1918 by Dr. William Whitney Christmas, a doctor with no engineering background, it was claimed to be capable of ending World War I by flying to Germany, kidnapping the Kaiser, and returning home. Christmas insisted its wings beat as a bird’s and would not put on struts or braces. Both of the test units fell apart while flying, killing the pilots. It’s only legacy: a permanent position in aviation history as one of the most ill-conceived designs ever undertaken.
9. Curtiss-Wright XP-55 Ascender
Nicknamed the “Ass-Ender,” this 1940s design turned fighter construction on its head. Its rear propeller, pusher; canard foreplanes; and two vertical tails were all designed to maximize the pilot’s visibility and leave the nose free for guns. In reality, it stalled effortlessly and was behind the times. Three were ever built, two of them crashing, so it’s remembered more for its strange layout than flying ability.
8. Vought V-173 “Flying Pancake”
The V-173 was a flying saucer, not an ordinary fighter. Charles Zimmerman had created it to use the entire body as a lifting surface with massive propellers creating short takeoffs and hover-like ability. It could almost hover in the air. When the Navy abandoned the project with the discovery of jets, the Flying Pancake remained one of the world of aviation’s strangest “what-if” machines.
7. Northrop XP-79 “Flying Ram”
Seminally living up to its hype, the XP-79 was designed to ram enemy bombers to oblivion. Made out of magnesium alloy, it was meant to be fast, agile, and strong enough to absorb the blow. It crashed on its maiden flight, killing test pilot Harry Crosby. The project was canceled immediately, but the plane is a striking demonstration of wartime excess and extreme design ambition.
6. Convair XFY Pogo
The 1950s Pogo was a “tailsitter” fighter meant to be launched vertically off tiny ships and then convert to flying horizontally. It had contra-rotating propellers and enormous power, but it was extremely difficult for pilots to transition to horizontal flight. The program was canceled secretly, but the rocket-like design of the plane is indelible.
5. Ryan X-13 Vertijet
The X-13 was built upon the tailsitter concept using a jet engine. It could take off and land vertically, fly level, and land nose-up on final approach to a special hook. Theoretically feasible, but dangerous, the landings required complicated support equipment. However, the aggressive tests advanced VTOL aircraft design.
4. Horten Ho 229
This Nazi WWII jet-powered flying wing had no tail or fuselage, making it a sleek, almost futuristic aircraft. It made a few test flights but never went to war. Its design did have an influence on today’s stealth planes like the B-2 Spirit, proving that even untested designs have the power to change the future of flight.
3. Convair F2Y Sea Dart
A supersonic fighter that can take off and land from the water? That was the promise of the Sea Dart, which used retractable hydro-skis. While it was supersonic in straight and level flight, its terrible water handling and one bad crash were enough to kill the program. It is the sole supersonic seaplane fighter ever built.
2. Rockwell HiMAT
The 1970s HiMAT (Highly Maneuverable Aircraft Technology) project pushed the envelope of outrageous agility. The small, delta-winged, radio-controlled jet was designed to handle high-speed, high-G maneuvers, and each flight test was piloted by five pilots flying in a coordinated command. Far from combat use, it still provided valuable data that had an impact on fighter design for several decades.
1. Nord 1500 Griffon
France’s Griffon 1500 Nord of 1959 combined forward-swept wings, canard configuration, and a hybrid power plant—turbojet for takeoff and high-speed ramjet. Griffon II achieved record speeds at 2,320 km/h in 1959, but never saw production as a production item due to its complexity. The short-lived aircraft, nonetheless, stands as one of the most extreme and technology-driven test jets ever built. From flapping wings to flying saucers, these aircraft demonstrate that military brilliance doesn’t necessarily follow the book. For each sleek, battle-tested fighter in history, there’s a bizarre prototype peacefully sitting in a museum, a testament that sometimes traversing the craziest ideas pays off with unexpected innovation.