On this day in aviation history, 81 years ago (June 6, 1944), the Lockheed XP-58 Chain Lightning made its first flight. While June 6, 1944, is best known as D-Day—the Allied invasion of Europe—the maiden flight of the XP-58 holds its own historical significance. Developed by Lockheed Aircraft Company, the XP-58 was designed as a long-range fighter and intended to improve upon the company’s highly successful P-38 Lightning.
Initially, the XP-58 was to be powered by two Continental IV-1430 engines. Two variants were proposed: a single-seat model armed with a 20mm cannon and four .50 caliber machine guns, and a two-seat version featuring an additional flexible .50 caliber gun mounted on each tail boom. In 1940, Lockheed decided the Continental engines would be underpowered and planned to replace them with two Pratt & Whitney XH-2600 engines. However, development of the XH-2600 was discontinued, prompting Lockheed to turn to the Wright R-2160 Tornado engines, which were also still in development. Unfortunately, delays plagued the Tornado project, and ultimately, Lockheed opted to use the Allison V-3420 24-cylinder liquid-cooled engines.
With the two Allison V-3420 engines, the XP-58 had a combined output of 6,000 horsepower. Only one prototype was built, and it achieved a top speed of 436 miles per hour, a range of 2,650 miles, and a service ceiling of 38,200 feet. The aircraft completed 25 test flights and generally flew well. However, the project was deprioritized in favor of other wartime aircraft needs. Maintenance proved challenging, especially with turbo-supercharger issues that caused overheating. Additionally, the aircraft’s pressurization and armament systems had yet to be designed or installed, which would likely have introduced further complications. In the end, the XP-58 project was canceled, and the sole prototype was believed to have been destroyed. Though the Chain Lightning never reached its full potential, it remains an intriguing “what might have been” in aviation history.
