Airbus ordered engine software checks on the A400M military aircraft following the recent fatal crash of Europe's new troop and cargo carrier. The request comes after the discovery of a potential anomaly in the system running the plane's turboprop engines. However, one person familiar with the findings said preliminary evidence gathered so far appeared to suggest a "quality" problem rather than a fundamental design flaw. Four crew members were killed when an A400M crashed in Spain on May 9 during a pre-delivery flight test. Airbus said it had issued an alert asking air forces to examine the plane's 'Electronic Control Unit'. The unit controls the engines and is part of a suite of software systems that were partly blamed for earlier delays and cost overruns in building the troop and cargo carrier. "To avoid potential risks in any future flights, Airbus Defence and Space has informed the operators about necessary actions to take," a statement said. The call for engine-related checks confirms an earlier Reuters report. So far, no clues have emerged from the 'black box' flight recorders and the potential area of concern that led to the checks was discovered by Airbus itself. "It is a precautionary measure which is part of our continued airworthiness activities," a spokeswoman said. The Airbus A400M was developed at a cost of 20 billion euros, marking Europe's largest defence project. It is powered by the West's largest turboprop engines, designed by Britain's Rolls-Royce, France's Safran and MTU Aero Engines of Germany. Problems in developing the engines, and particularly in certifying the engine control software, contributed to three years of delays and a new cash injection by governments in 2010. The Electronic Control Unit is one of two pieces of complex software that make up the engine control system, or FADEC, whose development was led by Munich-based MTU Aero Engines. MTU Aero Engines declined to comment. The crash came amid new delays in fitting the aircraft with military systems and raised further questions over the timing of deliveries after Spain suspended pre-delivery test flights. Airbus has said deliveries were "under review". The A400M has been delivered to Britain, France, Germany, Turkey and Malaysia, which is so far the only export customer. Other buyers include Belgium, Luxembourg and Spain. One person familiar with the probe said investigators were expected to focus on whether a faulty device had been fitted without adequate verification. Others said the fleet-wide checks were intended to check whether any more serious flaws had slipped through the thousands of hours of flight testing, something considered unlikely by people involved in steering the project out of past crises. "The cause of the crash will only be discovered if Airbus's findings are being matched with the data from the flight data recorder," a military expert said, asking not to be named. That comparison is however being complicated by the fact that black-box data is being kept private by a Spanish judge. The Spanish defence ministry, which is leading the official investigation, declined to comment, citing the judicial order. (Reuters)