Delays and cost overruns for the Lockheed Martin F-35 have not changed the US Air Force's plans to deactivate about 250 fighters later this year, says its chief of staff, Gen Norton Schwartz. The USAF, however, has begun destructive tests on Boeing F-15s and Lockheed F-16s to prove the viability for a potential service life extension programme, says Schwartz. "At 10-15% of the cost [of a new fighter] you could perform a service life extension programme," Schwartz says, "which would get us close to where we need to be in, we think, a more affordable way." Schwartz rejected buying the...