F-35 Lightning II successfully completed the first stage of its airborne refueling tests during the aircraft’s 34th flight yesterday. Aerial refueling capability will expand the F-35 operating envelope enabling longer duration flights. The milestone is another in a series leading to first production deliveries in 2010.

A specially instrumented KC-135 tanker from Edwards Air Force Base, Calif., is deployed to Fort Worth to support the refueling missions, which will continue over the next two weeks.

On Wednesday’s flight, Beesley climbed to 20,000 feet and performed a series of maneuvers to verify the F-35′s compatibility with the KC-135′s refueling boom and its aerodynamic wake. The sortie also evaluated aircraft systems and handling while connected to the refueling boom. All systems functioned as designed. Beesley reported that the F-35′s flight control system provided excellent handling qualities near the tanker, and while connected to the tanker refueling boom.

The Lightning II was aloft for one hour and 34 minutes and completed multiple tanker engagements. “The test team is completely satisfied we can maneuver in the vicinity of the KC-135, and the tanker boom can easily connect with the F-35,” said Doug Pearson, Lockheed Martin vice president of the F-35 Integrated Test Force. “We will begin to evaluate the F-35 fuel system during the next refueling test mission by transferring various amounts of fuel from the tanker.”

The F-35 carries a prodigious amount of internal fuel — more than 18,000 pounds — giving it exceptionally long range without external tanks, and dramatically reducing its need for tanker support. The internal-fuel configuration enables the Lightning II to remain stealthy by avoiding
external tank carriage typically used by legacy fighters to extend range. Drop tanks reflect radar energy and can betray an aircraft’s location. Operating without drop tanks also frees more stations for external weapons carriage when stealth is not required to fulfill mission objectives.