BRISTOL, England — Europrop International (EPI) expects the last of four inspected and repaired TP400 engines to be delivered this week to Airbus Military, clearing the way for the resumption of delayed functional and reliability (F&R) flight testing of the A400M.

The tests, which are required for full type certification of the European airlifter, were interrupted in July because of the detection of metallic chips in the turboprop’s oil system. The engines were removed and investigations revealed the culprit to be a crack in a cover plate within the propeller gearbox.

EPI says the cover plate is buried deeply behind the turboprop and gearbox and is time-consuming to replace with a unit which has been redesigned as a result of the lessons learned in flight testing. It adds that the timing of the resumption of reliability tests is up to Airbus, which was roughly halfway through the 300-flight-hour F&R phase when the chips were detected.

Airbus Military, meanwhile, says it hopes to resume flights of the F&R test airframe MSN6 in November to complete the remaining 140 hr. of testing as quickly as possible.

The overall delay to certification tests will inevitably push back delivery of the first production aircraft to the French air force to the second quarter of 2013, though Airbus Military says plans remain on track for delivery of four A400Ms in total by the end of next year, one of them to Turkey. It also adds that deliveries of a further 10 aircraft, including the first to Germany and the U.K., remain on schedule for 2014.