In the wake of the unexplained crash of an A400M troop and cargo transport plane in Spain on May 9, Airbus has ordered a review of the software that controls the turboprop engines of that aircraft model. The crash killed a Spanish flight test crew and has led to the grounding of British, German, and Turkish A400Ms already in service. The French military has also restricted the use of its six Airbus transports.

Airbus has asked its military customers to conduct checks of the software in the electronic control unit (ECU) of the engines. "To avoid potential risks in any future flights, Airbus Defence and Space has informed the operators about necessary actions to take," Airbus executives announced in an official statement.

The A400M was developed as European replacement for the C-130 military transport. The aircraft, assembled in Spain, was a joint program of seven NATO countries; Airbus' contract for the program had a price tag of over $22 billion. Delays in delivery of the A400M led to cost overruns and a reshuffling of Airbus's management.

Problems with development of the engines for the aircraft—the largest turboprop engines ever built for NATO—and the certification of the software at the heart of the aircraft's engine control system were significant contributors to those delays, holding up the delivery of the aircraft for three years. Problems with integrating military systems into the aircraft have delayed full delivery of the aircraft even further; the Spanish aircraft that crashed was conducting predelivery test flights.

Airbus apparently found a "quality" problem in the ECU software that caused an anomaly in engine operations during its own testing in the wake of the crash. The software check "is a precautionary measure which is part of our continued airworthiness activities," an Airbus spokeswoman told Reuters.