Airbus SAS has admitted that a software problem caused its A400M transport plane to crash in an accident that killed four people last month.

Germany’s Handelsblatt newspaper reports the software in question was installed incorrectly, and that caused the A400M’s engines to stall shortly before the crash. However, the software itself was free from glitches.

Marwan Lahoud, Airbus’ chief strategy officer, said in an interview that the company believes there is no problem with the airplane itself. “The black boxes attest … that there are no structural defects, but we have a serious quality problem in the final assembly,” Lahoud said.

In a statement released ahead of publication, Handelsblatt wrote that the units which control the engines of the turboprop A400M military cargo and troop transport were poorly installed during final assembly, which could have led to the engines malfunctioning and the plane crashing.

But Airbus’s defense and space division told AFP that it was too early to draw any conclusions.
“We will need the full results of the investigation in order to have the full picture, so as long as there is no further communications from (the investigating authority) CITAAM it is too early to draw any conclusions from the accident,” it said in a statement.

The division added that “like all accidents, it will certainly be a combination of issues and not one single cause”.

It also said other A400M aircraft in service have already been subject to checks and are “100 percent protected from this failure”.

The May 9 accident occured shortly after aircraft MSN23 takeoff from San Pablo Airport in Seville, Spain, on its maiden flight. The plane crash landed, resulting in the deaths of four Airbus Defense and Space personnel. Two of the six people on board the plane, a mechanic and an engineer, survived the crash and were sent to a hospital in critical condition. Airbus has already told A400M operators – Germany, Britain, Turkey and France – to check the planes’ Engine Control Unit.

Last week, Tom Enders, CEO of Airbus, complained that Spanish authorities were witholding the black box data, which meant it couldn’t fully analyze what caused the crash.

Now, with the results in, Airbus officials will at least be relieved the plane’s design is not at fault. Nevertheless, they will need to carry out stringent checks to ensure that future software installs don’t go wrong.

Image credit: Benurs via Wikipedia