World War II was a period when the aviation technology revolution jumped ahead in leaps and bounds. With every belligerent racing to try and get the upper hand in the air, engineers designed some of the most innovative, unusual, and downright bizarre aircraft that have ever flown. From rocket-propelled interceptors to test flying wings, these were aircraft that frequently tested the limits of what could be done—and occasionally of sanity. Here are ten of the most impressive and unusual aircraft of the time, each with an independent tale of ambition and genius.
10. Martin PBM-5A Mariner
The PBM-5A Mariner was one of America’s most powerful patrol bombers, even beating the legendary PBY Catalina at several tasks. Designed by the Glenn L. Martin Company, it boasted a gull wing that left its engines above the spray of salt, and retractable wing floats to cut drag. Its bomb bay lay hidden in the fuselage, so it could fly more quickly when weighed down with bombs. Subsequent versions were even equipped with jet-assisted take-off rockets for short, high-angle climbs—ideal for rescue missions in choppy seas. Staffed by nine and equipped with several .50-caliber cannons, the Mariner paid its dues in the Battle of the Atlantic by sinking ten German submarines. Of the over a thousand that were built, just one survives today.
9. Curtiss XP-55 Ascender
The XP-55 Ascender resembled something out of a science fiction strip—its engine was mounted behind the pilot, it featured a canard wing at the front, and dual vertical tails mounted at the end of its wings. The unorthodox “pusher” design was supposed to provide improved visibility and concentrate firepower in the nose. Unfortunately, it had unpredictable stalls and never produced the desired performance. Three were constructed, and two were destroyed in crashes. The one that remains is a testament to how far engineers would push things to experiment.
8. Vought V-173 “Flying Pancake”
The bizarrely endearing V-173 became known by its nickname due to its body being round and flat and its massive propellers—over sixteen feet in diameter each. Conceived by Charles Zimmerman, the plane was able to lift off over an extremely short distance, and with a powerful headwind, it could nearly fly vertically. Its peculiar shape created lift over its entire surface, which provided helicopter-like maneuverability in flight. Although testing was successful, the Navy’s interest was already turned toward more speed-oriented jet aircraft, and the Flying Pancake never entered production.
7. Focke-Wulf 190D “Long Nose”
Designated as the “Langnasen” to German airmen, the Focke-Wulf 190D was an interception-capable high-altitude fighter equipped with a liquid-cooled Jumo 213 engine. Its top speed was raised to approximately 440 mph with this improvement and enabled it to engage Allied bombers at altitude. Equipped with 20mm and 13mm cannons, it was a formidable foe, but wartime production interruptions meant that it was never produced in the quantities that could have made the difference. Now, only a few remain on display in museums.
6. Nakajima Ki-43 Hayabusa (“Oscar”)
The Ki-43 Hayabusa, or “Peregrine Falcon,” was a long-legged and quick-flying fighter that surprised Allied pilots at the beginning of the war. Highly agile, it was one of Japan’s most ubiquitous fighters, with over 5,900 produced. Early models had no armor or self-sealing fuel tanks, but subsequent improvements corrected those limitations without destroying the plane’s legendary agility. There is only one complete example of the type preserved.
5. Mitsubishi A6M7 Reisen (Zero)
The Mitsubishi Zero was legendary enough for its speed and maneuverability, but the A6M7 model added even more capabilities. It was built for dive-bombing from smaller carriers with strengthened wings and bomb racks instead of a centerline fuel tank. This model was one of the last Zeros to fly, as the war went against the Japanese. Although more than ten thousand Zeros were produced in total, relatively few intact aircraft remain in original condition today.
4. Horten Ho 229
The Ho 229 was in a class by itself—a streamlined jet-propelled flying wing decades ahead of its time. Its unconventional shape cut both drag and radar signature, and its twin jet motors promised up to 600 mph speeds. The aircraft took to the air in prototype in 1944, but the war’s end came before it could go into production. Still, it was one of the most sophisticated ideas to come out of the war.
3. Messerschmitt Me 262
The Me 262 was the first operational jet fighter in the world, and when it emerged, it startled Allied pilots. It had a top speed of around 540 mph and nose-mounted heavy cannons, and could tear through bomber formations before the bombers had time to respond. Reliability and fuel shortages held it back from altering the war, but its design left a gigantic mark on postwar aircraft development.
2. Heinkel He 178 and He 280
The Heinkel He 178 is the first jet plane to have ever flown, which it did in 1939. Following on from this achievement, Heinkel produced the He 280, the first purpose-built turbojet fighter. With a top speed of in excess of 550 mph, the He 280 was a leading contender, but rival designs—such as the Me 262—got to production first. Nevertheless, these initial jets represented the beginning of a new age for flight.
1. Mitsubishi J8M1 Shusui / Ki-200
The number one position is held by the Mitsubishi J8M1 Shusui, a rocket-powered interceptor designed with Germany’s Me 163 Komet as its model. Developed to combat bombers at high altitudes, it was able to ascend to breathtaking heights in just minutes and achieve scorching speeds—but for only five minutes, as the fuel would then be depleted. Technical information from Germany came in pieces, so Japanese engineers had to improvise much of the development. Unfortunately, the prototype crashed during its initial test flight, and it killed the test pilot. The war broke out before the aircraft were further developed.
These planes are a testament to the daring experiments and risky leaps in technology that characterized WWII aviation. Some of them were breakthroughs, some failures, but all left their unique imprint on the history of aviation.