The crash of the A400M military transport aircraft earlier this month at an Airbus factory in Seville, Spain, may have been caused by the software that controls the plane's engines, which had apparently been improperly installed before its disastrous maiden flight, according to sources within Airbus who declined to be named.
Employees of the aviation group who spoke with Handelsblatt said the software used to control the engines, which is made by a Munich engine maker, MTU, was probably installed incorrectly, according to an initial investigation performed by the European consortium of civilian and military aircraft and defense suppliers.
Normally, MTU would have installed the software on the plane, but in this case, it was apparently installed directly by Airbus employees who were testing the aircraft, the employees said.
The software at the focus of the crash investigation is usually installed on the A400M by the makers of the engines, but in the case of the one that crashed in Spain, it was installed directly by Airbus workers.
The software error apparently caused three of the aircraft carrier's four turbo-prop engines to fail during takeoff.
The Airbus A400M crashed on May 9 during a test flight in southern Spain, killing four crew members. The transport carrier, Europe's largest, has been dogged by cost overruns and delays in a project that began in 2003 and has cost more than €20 billion ($22.2 billion).
The internal investigation by Airbus, according to sources, has pointed initially to software that controls the aircraft's large, four turbo-prop engines. An official report on the crash and its causes by Spanish authorities has not yet been released.
Most of the A400M aircraft that have already been delivered to clients -- just a fraction of a fleet that was supposed to be operational by now -- will remain grounded until Spanish investigators complete their work.
If Spain's evaluation of the plane's flight data recorder confirms Airbus's analysis, the defect may be limited to the improper installation of engine software on the lone plane that crashed -- not a design flaw in the software that could bring about a costly recall and more delays.
That would be a positive for Airbus and the German military, the Bundeswehr, which urgently needs the A400M aircraft for air transport.
Airbus' initial investigation apparently suggests that the software problem was limited to the aircraft that crashed in Seville.
"For that reason, it would be premature to worry about further delays in deliveries at this point," said one Airbus insider.
Airbus had plans to deliver 14 to 18 A400M aircraft to customers this year.
But the head of the Airbus' defense division, Bernhard Gerwert, warned against reaching premature conclusions. Determining the cause of the accident "on the basis of individual indications does not take all the facts into account," he said. The European aircraft maker also sent out an urgent technical warning to owners of the A400M to check the software before the next flight.
The warning also advised customers -- European and non-European militaries -- that more testing would be needed in the event the engine or one of its software control units had to be replaced.
The software at the focus of the investigation is usually installed on the A400M by makers of the jet's engines, but in the case of the plane that crashed in Spain, it was installed directly by Airbus workers. According to information obtained by Handelsblatt, the software had been improperly installed on the plane, leading to the failure of three of four engines shortly after takeoff.
Four crew members on the plane were killed, and two others were badly injured.
If the plane crash is ultimately attributed to human error, and not a technical or design flaw with the A400M, Airbus can go ahead and deliver the remaining 17 planes to customers as planned this year.
But this will only be possible if Spanish authorities confirm Airbus's initial results and decide against additional safety or technical requirements that would necessitate changes in design or production.
Since late 2014, Airbus has been negotiating with its customers -- typically national militaries -- to determine how many aircraft each will receive, and when.
Quality problems with Airbus' Spanish subsidiary had already led to delays in A400M deliveries.
There has also been talk of individual customers suing Airbus for damages.
German Defense Ministry officials have complained that they still have no credible delivery schedule from Airbus for deliveries.
The Airbus chief executive, Thomas Enders, in January replaced the top management team at Airbus's Spanish military aircraft subsidiary following quality control problems.
Fernando Alonso, a former Airbus chief test pilot, now heads the project.
Pilar Albiac-Murillo, previously in charge of quality assurance, is now head of production in Seville.
The new management team has introduced several changes, company officials have said.
On Tuesday afternoon, Airbus notified customers about the software error and issued an "urgent technical recommendation."
In it, A400M users were asked to perform a one-time inspection of the electronic control unit on each aircraft engine before flying the plane again.
The document also advised A400M customers that additional tests would be needed in the event an engine or electronic engine control unit needed to be replaced.
According to Airbus, the recommendation was the result of an internal analysis performed independent of the Spain's investigation.
The analysis included an evaluation of data collected before the aircraft took off.
Experts from France and the United States are assisting Spanish authorities in evaluating data from the flight data recorder, or black box, but they have not submitted their own report yet.
While France and Airbus continued to allow their aircraft to take off, Turkey, Germany and Great Britain chose not to conduct any further test flights after the accident. These militaries intend to keep the aircraft grounded until the official investigation report has been released.
Only then can negotiations with industry go forward over the delivery of additional aircraft, said an official in Berlin who declined to be named. The German Defense Ministry is currently examining ways to offset further delays in A400M deliveries.
On Tuesday afternoon, Airbus notified customers about the software error and issued an 'urgent technical recommendation.' A400M users were advised to perform a one-time inspection of the electronic control unit on each aircraft engine before flying the plane again.
The A400M is meant to replace the Transall, the main transport carrier of European militaries, which have been in service for decades.
Amid delays to the A400M, the use of Transalls will probably be extended once again, even though they were expected to be decommissioned by late 2018.
Other alternatives to the A400M are not being considered at this time, said a Defense Ministry spokesman who declined to be named. The German Air Force has already incorporated the new Airbus transport carriers into its structural and personnel planning.
If the accident were indeed the result of a one-time incident of human error in Seville, it would have consequences for the organization of final assembly at the Airbus plant there, but probably not for the entire program.
The consortium, which builds the powerful turboprop engines, would be off the hook. The makers of the plane includes Britain's Rolls-Royce, the French company Safran and Munich-based MTU.
The companies developed the TP-400 engine for the A400M, but none had previous experience making large turboprop engines. A spokeswoman for MTU declined to comment and referred questions to Airbus.
MTU in the 1950s had been owned by Daimler-Benz, the maker of Mercedes Benz, and BMW.
In 1969, Daimler Benz became sole owner, and following German reunification, MTU became a subsidiary of what eventually would become DaimlerChryler Aerospace or DASA. In 2004, DaimlerChrysler sold MTU to U.S. private equity firm Kohlberg Kravis & Roberts, which the following year took MTU public.
Shares of MTU traded in Frankfurt were up 0.4 percent at €87.84 in early trading on Wednesday. The shares had risen 1.3 percent since the crash. MTU is now owned largely by institutional investors such as Mondrian Investments, a U.S.-British money manager, SEB Bank of Sweden, UBS of Switzerland and Capital Group, a U.S. investment group.
Airbus, as the aircraft manufacturer, is the general contractor for the A400M, and is liable for legal problems.
Various manufacturers developed the engine control system.
The software, which regulates thrust for each of the 11,000-horsepower engines, is made by MTU.
Safran subsidiary SNECMA manufactures the ECU control unit, while MTU produces the EPMU control unit, which was in fact intended to iron out problems with the ECU.
Other software problems have dogged the project and led to the A400M's current backlog of deliveries.
Engineers were unable to overcome a phenomenon called "propeller flutter," and software had to be revised several times.
But if investigators find that structural problems, not a one-time software error on a single plane, had led to the accident, it could be damaging for Airbus, the main commercial aviation rival to Boeing and a supplier of European and other militaries around the world.
Yann Derocles, an analyst at Bank Oddo in Paris, said the initial findings of an isolated software error were a positive sign for Airbus, MTU and Safran.
If the crash was truly caused by a problem in final assembly and was unrelated to the structure of the aircraft, "it would come as a relief, especially in light of the export program the company is aiming for," he said.
According to Mr. Derocles, the cause of the crash appears to be less serious than was feared a week ago, although he stressed that this would also depend on the official outcome of the independent investigation.
Airbus hopes to be able to sell the A400M to more customers than those on its initial list of buyers. Only then can the European consortium hope to make a profit from a program that has run way beyond its initial cost estimates.
Spain's military aviation accident investigation agency, CITAM, is conducting the official investigation.
The Spanish authorities had sent the cockpit voice recorder and black box data recorder to their French counterparts at France's state aircraft investigation agency, BEAD, in Paris. One of the black boxes was sent to the manufacturer, U.S.-based L 3 Communications, because it had been heavily damaged and investigators had had trouble analyzing the information it contained.
Markus Fasse is a Handelsblatt editor who writes about aviation from Munich. Thomas Hanke is a Handelsblatt in Paris. Till Hoppe is a Handelsblatt editor who covers the German Defense Ministry, among others, from Berlin. To reach the authors: [email protected], [email protected] and [email protected]