Lockheed Martin has begun taxi trials in preparation for the first flight of the F-22, possibly by the end of this month, after testing the fighter's 156kN (35,000lb)-thrust Pratt & Whitney F119 powerplants at full afterburner, with the aircraft tied down. A series of minor software problems, including over-sensitive sensors and a locking brake, has slowed progress. First flight has been delayed since May.

Source: Flight International