Pratt & Whitney’s F135 engine has achieved a first for the Lockheed Martin F-35 program by accelerating the F-35B STOVL version through the sound barrier last month. The test aircraf–BF-2–climbed to 30,000 feet and accelerated to Mach 1.07 at the off-shore test track near NAS Patuxent River in Maryland on June 14. The F-35 has supercruise capability and does not require the use of engine afterburner to achieve supersonic flight. The F135’s 28,000-pound dry thrust (without augmentor) is capable of accelerating the fighter beyond Mach one, and with the augmentor lit the thrust increases to 43,000 pounds.

This is the third F-35 test aircraft to fly supersonic after two other F-35A CTOL jets earlier in the flight-test program. At this point the F135 program has completed more than 17,600 hours of testing, culminating in the conventional takeoff and carrier variant aircraft receiving Initial Service Release in February 2010.

Bennett Croswell, vice president of F135 and F119 engine programs said, “This is truly a historic accomplishment, not just for Pratt & Whitney and the F135 team, but really for all of military aviation. This is the first time ever, in the history of aviation, that a production-ready, stealthy, short takeoff vertical landing capable aircraft has flown supersonic.”