EPI Still Assessing A400M Gearbox Issue

Jun 22, 2011 By Robert Wall AviationWeek.com

LE BOURGET - Europrop International (EPI) is set to build the initial powerplants for the first A400M production version, even as it continues to examine the inflight failure of a gearbox on the TP400-D6 turboprop powering the EADS Airbus Military airlifter. The mishap prevented the A400M from taking part in flight displays at the Paris air show.

The pinion gear that failed controls whether the engine is left- or right-handed (i.e., the direction of propeller rotation). The development-standard gearbox is still in inspection and a root cause fault has not been identified, EPI President Simon Henley says.

A new engine to return test aircraft MSN1 to its base is ready to be installed. The team inspected other gearboxes and deemed it safe to continue flight trials. Henley notes that the failure mode is benign with the engine shutting down.

Overall, engine flight time on-wing tops 6,500 hr., with 95% of performance tests completed, says Martin Maltby, program technical director. The engine is beating fuel-burn targets by around 1%, he notes.

In the fourth quarter, EPI plans to freeze the configuration of the production-standard engine, for delivery of the first of those next year. This engine features an aluminum gearbox for greater durability, as well as improvements in the high-pressure compressor and combustor, Maltby says.

Three more software loads — one coming in September — are planned before military certification. Software problems were encountered early on in the full-authority digital engine control, but those milestones are now being met, Henley notes.

So far, five sets of development engines and four spares have been delivered, with four more engines to come before year end.