The Airbus Military A400M is facing further challenges to its flight-test campaign, following two engine-related issues encountered during ground trials.

Airbus executive vice-president programmes Tom Williams says there have been "a couple of failures" of the Europrop International TP400-D6 engine during ground testing, including engine No 5 during water ingestion trials and engine No 6, which suffered a "gearbox problem".

EPI confirms that it has recently encountered such issues, but says initial indications suggest the water-ingestion issue was potentially due to a "process anomaly". The engine involved in the high-endurance gearbox testing incident is in the process of being stripped, it adds.

 TP400 rig
© Europrop International

Speaking on the sidelines of the Emirates Airbus A380 delivery in Hamburg, Williams said that achieving the A400M's first-flight target of the end of October will be "tight" and depends on the results of the strip-down and inspection of these two engines, as well as the development of the engine's full-authority digital engine control software. "This is not available until the end of October - we've got an interim release and a lot will depend on how good that is," he says.

The next critical stage in the path to first flight of the A400M is the launch of TP400 flight trials on board a Marshall Aerospace-owned Lockheed Martin C-130 testbed (below). This had been hoped for by the end of July, and the aircraft needs to accumulate 50 flight hours ahead of the A400M's debut. "The first 12h of this must be flown in dry conditions," says Williams. However, Marshall confirms that the aircraft has performed just four ground runs to date.

 TP400 testbed
© Marshall Aerospace

Delivery to the first customer - France - had been due in October 2009, but lead A400M stakeholder EADS has already acknowledged that this will be delayed by six months, with a risk of a further six-month slip. Williams says that every week that the first flight slips beyond October will mean another week's delay to the delivery, as there is not sufficient slack in the flight-test programme to make that time up.