After the P-38 Lightning’s success, Lockheed started work on developing advanced types based on the same design. This was known as the XP-58 project. The initial request was for a heavy fighter with increased range and able to operate at higher altitude. In April 1940 an agreement between the US government and Lockheed was signed, and the development began.
James Gerschler, the project engineer at Lockheed, was appointed head of the project. By May 1940 two design concepts had been proposed for one single-seater and one two-seater aircraft, the commission at Wright Field chose the two-seater modification as it suggested heavier armament.
The project was designated XP-58 and was initially planned to become an escort fighter. The first 2 months of design work showed that Continental engines rated at 1500-1600 HP would not be sufficient for the aircraft so they were changed to Pratt & Whitney XH-2600-9/11. This change was only the first in a long row of modifications ahead of the design team.
After extensive changes made during the construction stage, the first prototype finally rolled off the assembly line in August 1942. At the same time, Lockheed received permission and funding to construct the second prototype. The specifications continued to change. In 1943 it was reconfigured to carry a 75mm cannon and two high-caliber machine guns. Later, the USAAC decided to convert the XP-58 into a two-seater attack aircraft that was intended to carry six 20mm cannons, later still a variant with 37mm cannons was considered. Both of these versions were rejected because the significant size of the aircraft made it a perfect target. Moreover critical parts were not armored which increased the risk of high probable losses. Another suggested modification was to make the XP-58 into a high-speed bomber. Naturally all these design requests could not be fulfilled by the small team of engineers and the work was delayed.
Eventually, the specification changed once again, and the XP-58 once again reverted to its original role – namely heavily armed bomber destroyer. This required removing the defensive rear turret.
The prototype itself had undergone such extensive changes that it had never been equipped with both forward-facing and defensive armament. It conducted its maiden flight on June 6 1944 when it was flown from Lockheed’s airfield to Muroc airfield (currently Edwards AFB). The flight duration was 50 minutes.
The final fate of the Chain Lightning was unfortunate. Between the poor reliability of the turbo-superchargers that were supposed to be installed on the fighter and the incredible number of modifications and difficulties encountered by the design team during its construction, Lockheed abandoned the development program in 1945.