Article Summary: The F-89 Scorpion was an innovative Cold War jet, but it had a fatal flaw—its wings were prone to catastrophic failure. This defect caused multiple deadly crashes, including the infamous 1952 Detroit Air Disaster, where an F-89 disintegrated mid-air during an airshow, killing both pilots.
Key Point #1 – Engineers later discovered that the aluminum alloy used in the wings became brittle under stress, leading to sudden structural failure. After extensive redesigns, the Scorpion became more reliable, but its troubled history remains a cautionary tale in aviation engineering.
Key Point #2 – Learn how a wing defect nearly doomed the F-89 Scorpion and led to critical aircraft safety advancements.
The F-89 Scorpion Had a Major Wing Issue, Causing Many Deaths
The F-89 Scorpion was an all-weather, twin-engined interceptor aircraft designed and produced by the American aircraft manufacturer Northrop Corporation.
It was the first jet-powered aircraft designed for the interceptor role to enter service and the first combat aircraft armed with air-to-air nuclear weapons, the unguided Genie rocket.
The name Scorpion came from the aircraft’s thin rear fuselage, elevated tail unit, and high-mounted horizontal stabilizer, which kept it clear of the engine exhaust. Northrop’s engineers dubbed it the Scorpion, and the Air Force decided to keep the name.
During the International Aviation Exposition in Detroit, Michigan, in front of over 51,000 people on August 30, 1952, an F-89 disintegrated in mid-air, killing the two pilots, injuring several people on the ground, while 20mm shells from the aircraft’s guns were exploding.
A Brief History of The F-89 Scorpion
In August 1945, the US Army Air Forces (USAAF) issued a specification for a night fighter to replace the P-61 Black Widow. The Army wanted a twin-engine aircraft with six guns and a top speed of 530 mph. At the time, the Air Force was still a unit of the Army, and the USAAF didn’t become the US Air Force until 1947.
Design crews sent six proposals to the Army, and the Army selected two, the Northrop aircraft dubbed the N-24 and another by Curtis Wright, the XP-87 Blackhawk, the last aircraft produced by the company.
Jack Northrop’s original design of the N-24 was a slim-bodied, swept-wing aircraft with a two-person pressurized cockpit and conventional landing gear. Two Allison J35 turbojet engines were buried in the lower fuselage to reduce drag. The engines sat directly behind their air intakes, with the exhaust underneath the rear fuselage. The horizontal stabilizer was mounted just above the junction of the vertical stabilizer and the fuselage.
Of course, the Army wanted several changes. The inspectors believed the radar operator needed to be moved closer to the pilot, with a single canopy covering the cockpit. Magnesium alloy components of the wing replaced aluminum alloy materials, and the fuel tanks located directly above the engines were moved. The swept wings proved less satisfactory at low speeds, so a thin, straight wing was selected instead—however, this reduced performance.
The first F-89 Scorpion was accepted into the USAF on September 28, 1950. Following the crash in Detroit, all F-89 Scorpions except test aircraft were grounded on September 22, 1952.
On January 7, 1953, the F-89D was introduced to service. It removed the 20mm cannons in favor of a new Hughes E-6 fire control system with AN/APG-40 radar and an AN/APA-84 computer. Armament was two pods of fifty-two 2.75-inch (70 mm) “Mighty Mouse” FFAR rockets.
The F-89D was the most produced version of the Scorpion, with 862 built. It had a maximum speed of 636 mph, maximum range of 1,367 miles, and a service ceiling of 49,200 ft.
Poor Shooting Over Los Angeles
In August 1956, a pair of F-89D interceptors scrambled from Oxnard Air Force Base to shoot down a runaway F6F-5K Hellcat drone, leading to the Battle of Palmdale. The interceptors fired all their rockets but failed to damage the Hellcat drone. It was an embarrassing episode for both the Navy and the Air Force, who fired 208 rockets at the drone and didn’t hit it once.
Detroit Air Disaster
On the afternoon of August 30, 1952, at the International Aviation Exposition in Detroit, when a pair of F-89 fighters were attempting a low-altitude fly-by, a horrific accident occurred.
Two F-89Cs of the 27th Fighter Interceptor Squadron, 4711th Defense Wing, based at Griffis Air Force Base, Rome, New York, made a low-altitude, high-speed pass in front of 51,000 spectators, including General Hoyt S. Vandenberg, Chief of Staff, United States Air Force.
Suddenly, the left wing of the lead fighter separated. The tail also broke away, and the fighter crashed and exploded. In the resulting fire, the Scorpion’s 20-mm cannon shells detonated.
The Detroit Free Press newspaper reported, “The crash occurred 4:40 p.m., toward the end of the day’s show. Adams and Richter [the pilots] were swooping down over the field in a ‘fly-by,’ Adams flying to one side and slightly to the rear of Recher.
“Suddenly, Adams’ plane swerved to the right. A piece was seen to break off, then an instant later, the right wing tore off.
“As the pilot struggled to gain altitude, the left wing and tail section ripped off, and the hurtling fuselage continued across the field. It crashed between the railroad tracks and the Willow Run Expressway.
“It ripped up tracks, fences, and telephone lines. Heat from the burning wreck turned the rails cherry red.”
Major Donald E. Adams, a fighter ace who had been awarded the Silver Star in Korea just months earlier, was killed, along with his radar intercept officer, Captain Edward F. Kelly, Jr. Five people on the ground were injured by falling wreckage.
F-89.
Wing Issues And Turbulence Caused The Crash
The Air Force later related that the crash was probably caused by turbulent air near the ground, added to the stress put on the plane by the maneuver, plus the thrust of the afterburners, devices which give the aircraft added thrust.
It wasn’t the first or last crash involving the F-89 wings shearing off. Northrop engineers discovered that the aluminum alloy used in the production of the wings had properties that weren’t understood at the time, but when subjected to certain types of dynamic loads, it could fatigue and become brittle rapidly. It was also susceptible to surface imperfections, such as scratches or machining marks, that could rapidly generate fatigue fractures.
Another issue was that, under certain conditions, the Scorpion’s wings could begin to sway back and forth, actually twisting the wing. This occurred so quickly that a pilot would not likely see it happening. The twisting motion focused on the wing attachment points, resulting in a catastrophic failure.
Northrop redesigned the wing to reduce the oscillation and replaced the aluminum attachment fittings with new ones made of forged steel.
The F-89 was returned to service and became a reliable airplane for the rest of its service life. The Northrop F-89 was retired from active service by the USAF in 1960. However, the aircraft continued duties with the ANG (Air National Guard) until 1969.
About the Author
Steve Balestrieri is a 19FortyFive National Security Columnist. He served as a US Army Special Forces NCO and Warrant Officer. In addition to writing for 19FortyFive, he covers the NFL for PatsFans.com and is a member of the Pro Football Writers of America (PFWA). His work was regularly featured in many military publications.
