PARIS, Dec 12 (Reuters) - Europe's biggest military plane project, fraught with delays and in-fighting, faces a critical test as the A400M's mammoth turbo prop engine prepares for a secretive flight next week from a quiet corner of east England.
Coming on the heels of UK defence cuts, the operation is key for the credibility of Airbus parent EADS as it tries to renegotiate a loss-making 20 billion euro contract for the A400M and project itself as a reliable global defence supplier.
The West's biggest turbo prop was developed by a group of engine makers assembled to keep high-tech jobs inside Europe, overriding the planemaker's preference for an imported engine.
The engine tests are being kept under wraps following months of tensions over delivery delays between Airbus Military, its engine makers and some of the seven European NATO nations behind the 25-year-old project to build a new heavy transporter.
But industry sources say the plane being used for the test, a modified C-130 transporter, should make its first flight with a Europrop TP400-D6 engine next week depending on the weather.
The test will be carried out by replacing one of the C-130's own engines with the larger new engine and taking it aloft.
EADS and Airbus Military declined to comment.
Even the choice of plane used for testing has been criticised after part of the C-130 melted in ground tests.
"It is way too small. They should have used an A340," a senior industry official said, referring to the large Airbus jet.
Industry analysts said the disputes had shown the limits of of treating big military contracts like commercial jet deals.
In a bid to develop Europe's own capacity for dropping troops into combat zones without repeating the cost overruns, delays and compromise surrounding the Eurofighter; A400M nations enforced a commercial contract with penalties for late delivery.
But EADS says its efforts to absorb risk were stymied by a political decision to involve all of Europe's key engine makers. It had wanted an engine from Pratt & Whitney Canada.