Bell Boeing MV-22 Osprey tiltrotor test aircraft are expected to resume flight testing by September with the rest of the fleet flying a year later.

US Marine Corps Col Nolan Schmidt, the V-22 programme manager, says US military leaders will soon reveal how many V-22 tiltrotor aircraft Bell Boeing will build in the interim until technical problems are fixed.

A panel formed to review the programme after two high profile crashes suggested that it may take two years to correct deficiencies (Flight International, 24-30 April).

Schmidt says "we need to clean some of our dirty laundry". He adds: "We've got some hardware and software fixes to make. We need to go back and clean up the hydraulic system's design." Schmidt thinks the redesign work is "fairly straightforward, but we must go through the whole design to make sure it is".

Schmidt believes test aircraft will be cleared for flight by September, but adds that it is unclear when production-standard V-22s will fly. Estimates range between January and September next year.

Speculation in Washington suggests that V-22 annual production will be held at 12 aircraft until the fixes are in place.

Source: Flight International