The incident taught Navy pilots a valuable lesson about flying faster than the bullets in front of them.

On September 21, 1956, test pilot Tom Attridge was piloting a F-11 Tiger fighter jet off the coast of Long Island. During a high-speed gunnery test, Attridge performed a fairly remarkable feat—albeit an embarrassing one—when he struck his own aircraft with 20mm cannon fire. The incident remains, 70 years later, one of the oddest mishaps in aviation history. 

About the F-11 Tiger

• Year Introduced: 1956
• Number Built: 199
• Length: 27 ft 4 in (8.33 m) with wingtips folded
• Wingspan: 31 ft 7.5 in (9.64 m)
• Weight (MTOW): 23,459 lb (10,641 kg)
• Engines: One Wright J65-W-18 afterburning turbojet (7,450 lbf thrust)
• Top Speed: 726 mph (1,169 km/h) / Mach 1.1
• Range: 1,280 mi (2,060 km)
• Service Ceiling: 49,000 ft (15,000 m)
• Loadout: Four 20mm Colt Mk 12 cannons; 4 hardpoints equipped to carry rockets, missiles, drop tanks
• Aircrew: 1

The F-11 was an early supersonic US Navy fighter that entered service in the mid-1950s. Used for fleet air defense before the F-14 Tomcat would more famously assume the role, the F-11 was armed with four 20mm cannons—a choice of armament that would come back to haunt test pilot Tom Attridge.

Tom Attridge’s Interesting F-11 Test Flight

The 1950s were a time of extraordinarily rapid development in the aviation world. World War II saw the creation of the jet engine as a major upgrade to the propeller, and fighter jets had become standard by the Korean War. In 1947, test pilot Chuck Yeager first broke the sound barrier, and in the decade that followed, both the United States and the Soviet Union mass-produced supersonic aircraft. As both sides experimented with aerial operations at hitherto unprecedented speeds, many of the procedures that are fully rote today were still being ironed out. In particular, many flight and weapons behaviors were not yet understood—making what happened with Attridge in 1956 feasible.

Attridge began a test profile at 22,000 feet of altitude, performing a 20-degree supersonic dive. At 13,000 feet, Attridge fired a 4-second burst from his cannons. At the moment he fired, his F-11 was traveling at 768 miles per hour. The bullets left the muzzle with a velocity of 2,000 miles per hour.

When combined with the aircraft’s speed, this meant the bullets were traveling extraordinarily fast. But the bullets slowed immediately due to air resistance, following a curved, decaying trajectory downwards. Meanwhile, the aircraft continued to dive with engines running at full blast, accelerating to 880 miles per hour. Accordingly, 11 seconds after Attridge fired the cannon burst, his aircraft overtook its own bullets. 

Attridge’s F-11 was hit with at least three rounds. One shattered the armored windshield; one hit the nose cone; and one entered the engine intake. The compressor blades shredded and engine power was reduced by 78 percent. Attridge attempted to return to Grumman airfield in Calverton, NY, flying slowly to prevent the damaged windshield from collapsing. But the engine failed just one or two miles short of the runway. At the time of the failure, Attridge was already too low to eject, and crash-landed in a wooded area 

Miraculously, Attridge survived the incident with a broken leg and broken vertebrae. It helped that his plane was only equipped with non-explosive practice rounds for the test, reducing the damage and making the flight back to the airfield mostly possible. Attridge fared better than the F-11, which was destroyed in the crash and never returned to service. But the Navy certainly preferred this outcome to the other way around.

The Navy Changed Firing Protocols After the Self-Shootdown

Initially, the incident was considered a one-in-a-million fluke. However, after the Navy analyzed the incident, it confirmed that it could be fully explained by physics. Changes were implemented accordingly, with a new procedure that pilots must turn or change altitude after firing to avoid intersecting with their own bullets.

Today, the incident remains one of the stranger accidents in aviation history. But it wasn’t a fluke. It was a preview of the hazards of the supersonic age, when modern technology outpaces the assumptions or intuition of human operators in a way that required a more structured and controlled testing environment. 

About the Author: Harrison Kass

Harrison Kass is a senior defense and national security writer at The National Interest. Kass is an attorney and former political candidate who joined the US Air Force as a pilot trainee before being medically discharged. He focuses on military strategy, aerospace, and global security affairs. He holds a JD from the University of Oregon and a master’s in Global Journalism and International Relations from NYU.

The post In 1956, a US Navy Test Pilot Shot Down His Own Plane appeared first on The National Interest.