What did the Constellation have in common with the P-38 Lightning fighter?

When Lockheed's engineers, with Kelly Johnson and Hall Hibbard on the team, designed the Constellation based on TWA's 1939 order, they did not start from scratch. The wing of the new four-engine airliner closely resembled that of the P-38 Lightning, the twin-engine, twin-tail fighter Lockheed had developed for the US Army, differing from it mainly in size. The fact that an airliner inherited the wing shape of a fighter plane sums up the company's working method well: it reused what it had already tested.

The wing was not the only distinctive feature. The Constellation had a nose-wheel landing gear, unusual for large aircraft of that era, and its characteristic triple tail was chosen to reduce the aircraft's overall height, since a single vertical stabilizer would have had to be much taller to provide the same control. Then there was the dolphin-shaped fuselage with its continuously changing profile, which today is the most recognizable feature for any enthusiast.

The connection to the P-38 also extended into the cockpit. On the maiden flight of the XC-69 prototype on January 9, 1943, Edmund Allen, Boeing's chief test pilot, was the pilot, and Milo Burcham, a Lockheed test pilot known for having flown the P-38 Lightning prototype, was the co-pilot. The two alternated at the controls throughout the flight, which ended at Muroc Dry Lake, and Burcham then flew the aircraft back to Burbank in 31 minutes.