What was the first aircraft to fly with variable-geometry…

What was the first aircraft to fly with variable-geometry wings?

Short answer

The Bell X-5 was the first aircraft able to change its wing sweep in flight: its two examples first flew on 20 June and 10 December 1951. It was inspired by the German Messerschmitt P.1101, which was never actually tested. The F-111, by contrast, was the first production aircraft with variable-geometry wings.

Published: November 5, 2026 · Updated: November 5, 2026 · Edited by Above Ten Thousand · Editorial policy

What was the first aircraft to fly with variable-geometry wings?

X-5 on Ramp DVIDS

The first to move its wings in flight

The Bell X-5 was the first aircraft capable of changing its wing sweep in flight. Two examples were built, making their first flights on 20 June and 10 December 1951. The project was inspired by the design of the Messerschmitt P.1101, conceived in Germany during the war and never actually tested.

The P.1101 and the Pterodactyl

Some design features of the Me P.1101 were later used by Bell as the basis for the X-5. On the P.1101 itself, test flights were planned with the wing set at 35, 40, and 45 degrees of sweep. On the Pterodactyl IV, one of the versions of the Westland-Hill Pterodactyl, the wings had variable sweep within a small range of angles, in order to allow longitudinal trimming in flight since the aircraft had no horizontal stabilizer.

The first in production: the F-111

The F-111 was the first production aircraft with variable-geometry wings. The F-111A made its first flight on 21 December 1964 from Carswell Air Force Base in Texas. Its sweep could vary between 16 and 72.5 degrees, from the fully forward position to maximum sweep.