The first optimised conventional take-off and landing (CTOL) variant of the F-35 Lightning II fighter for the US Air Force has successfully completed its inaugural flight.

During the 89-minute flight, the Lockheed F-35A, called AF-1, flew to 20,000ft at Mach 0.6.

The aircraft performed 360° rolls by lifting the nose to 20° angle of attack during the flight.

A fifth generation fighter, the F-35 II combines advanced stealth with fighter speed and agility, fully-fused sensor information, network-enabled operations and lower operational and support costs.

The aircraft incorporates many improvements and updates derived from the test programme of AA-1, the first F-35.

The AF-1 will join two F-35B short take-off / vertical landing variants, which are currently undergoing flight testing.

Lockheed, along with Northrop and BAE, is developing the F-35 for nine countries including the US.