The long-awaited first flights of the Boeing and Lockheed Martin Joint Strike Fighter (JSF) demonstrators could take place by the end of next month, after Pratt & Whitney completes final tests on the two JSF119 conventional take off and landing (CTOL) engine variants.

"We have not officially obtained flight clearance [for the engines], but we hope to by the end of this month," says P&W JSF programme director Bob Cea. Tests of the JSF119-611 for Lockheed Martin's X-35A CTOL concept demonstrator were completed in early April. Final accelerated mission and high cycle fatigue tests on the JSF119-614 for Boeing's X-32A were completed last week.

Test data is being scrutinised by the JSF Joint Programme Office (JPO) which is checking off 1,550 pre-clearance test points. Although a late June flight would represent only a two-to-three month slip in the CTOL schedule, more serious delays threaten the short take-off and vertical landing demonstrators, which are unlikely to be cleared to fly until November.

Delays centre on the verification of software that enables the engine control system to communicate with the integrated propulsion control and vehicle management systems. Cea says the aim is still to fly all four JSFs by year-end.

Source: Flight International