Software bug brought down Airbus A400M military transport plane

Airbus alerts customers to potential bug urging them to conduct 'specific checks'

Aircraft maker Airbus has urged customers of its A400M military transport plane to conduct "specific checks of the electronic control units (ECU) on each of the aircraft's engines" after uncovering a software bug that may have caused a crash of one of the aircraft on the 9 May.

The alert from Airbus "requires operators to perform one-time specific checks of the electronic control units (ECU) on each of the aircraft's engines before the next flight and introduces additional detailed checks to be carried out in the event of any subsequent engine or ECU replacement," warns the statement.

The warning, it adds "results from Airbus Defence and Space's internal analysis and is issued as part of the Continued Airworthiness activities, independently from the ongoing Official investigation".

The software bug caused three of the plane's four engines to shut down during a pre-delivery test flight, according to a report in German newspaper Der Spiegel.

"The investigation claims that shortly after the start of the test machine three engines received contradictory orders from the computers and then turned off the power," according to the report.

"The pilots testing the A400M, could not do anything, according to Airbus investigators. While they were trying to return the 45-meter-long plane back to the airport in Seville, Spain they could no longer control it properly. The machine touched a power line, crashed into a field and burned out almost completely."

However, the precise details of the software bug has not yet been disclosed, while the black box flight recorder, which ought to shed more light on the crash, remains under the control of the judge in Spain. According to Reuters, the investigation into the crash is being led by the Spanish defence ministry.

"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 told Reuters. That comparison can only be made after the black-box-data is released, it added.