Germanwings Flight 9525

Investigation

The French Bureau of Enquiry and Analysis for Civil Aviation Safety (BEA) opened an investigation into the crash; it was joined by its German counterpart, the Federal Bureau of Aircraft Accident Investigation (BFU). The BEA investigation was led by Arnaud Desjardin and was assisted by the United States Federal Bureau of Investigation. Hours after the crash, the BEA sent seven investigators to the site; these were accompanied by representatives from Airbus and CFM International. The cockpit voice recorder, which was damaged but still functional, was recovered by rescue workers and examined by the investigation team. The following week, Brice Robin, the government prosecutor based in Marseille, announced that the flight data recorder, blackened by fire but still usable, had also been found. Investigators isolated 150 sets of DNA, which were compared with the DNA of the victims' families.

Cause of crash

According to French and German prosecutors, the crash was deliberately caused by the first officer, Andreas Lubitz. Robin said Lubitz was courteous to Captain Sondenheimer during the first part of the flight, then became "curt" when the captain began the midflight briefing on the planned landing. Robin said that when the captain left the cockpit, possibly to use the toilet, Lubitz locked the door and overrode the door code from the inside, preventing anyone from entering. The captain requested re-entry using the intercom; he knocked and then banged on the door, but received no response. The captain then tried to break down the door, but like most cockpit doors made after the September 11 attacks, it had been reinforced to prevent intrusion. During the descent, the co-pilot did not respond to questions from Marseille air traffic control, nor did he transmit a distress call. Robin said contact from the air traffic control tower, the captain's attempts to break in, and Lubitz's steady breathing were audible on the cockpit voice recording. The screams of passengers in the last moments before impact were also heard on the recording.

After their initial analysis of the aircraft's flight data recorder, the BEA concluded that Lubitz had made flight control inputs that led to the crash. He had set the autopilot to descend to 100 ft and accelerated the speed of the descending aircraft several times thereafter. The BEA preliminary report into the crash was published six weeks later, on 6 May 2015. It confirmed the initial analysis of the aircraft's flight data recorder and revealed that during the earlier outbound Flight 9524 from Düsseldorf to Barcelona, Lubitz had practised setting the autopilot altitude dial to 100 ft several times while the captain was out of the cockpit.

The BEA final report into the crash was published on 13 March 2016. The report confirmed the findings made in the preliminary report and concluded that Lubitz had deliberately crashed the aircraft as a murder–suicide. The report stated:

Investigation of Lubitz

Three days after the crash, German detectives searched Lubitz's Montabaur properties and removed a computer and other items for testing. They did not find a suicide note nor any evidence that his actions had been motivated by "a political or religious background". During their search of Lubitz's apartment, detectives found a letter written by a doctor indicating Lubitz had been declared unfit to work. Germanwings stated it had not received a sick note from Lubitz for the day of the flight. News accounts said Lubitz was "hiding an illness from his employers". Under German law, employers do not have access to employees' medical records, and sick notes excusing people from work do not give information about medical conditions, so employers must rely on employees to declare their lack of work fitness.

The following day, authorities again searched Lubitz's home where they found evidence he suffered from a psychosomatic illness and had been prescribed two antidepressants, escitalopram and mirtazapine, and a sleep medication, zopiclone. Toxicological examination of Lubitz's post-mortem revealed the presence of all three. Escitalopram, a selective serotonin reuptake inhibitor, is associated with a risk of suicidal thoughts and behaviours, especially soon after treatment is commenced. Lubitz was prescribed escitalopram nine days before the crash. Criminal investigators said Lubitz had then, in the week before, researched online "ways to commit suicide" and "cockpit doors and their security provisions". Robin said doctors had told him Lubitz should not have been flying, but medical secrecy requirements prevented his physician from making this information available to Germanwings. Such secrecy should consider public safety, said BEA investigator Arnaud Desjardin.

The investigation into Lubitz revealed his treatment for suicidal tendencies prior to his training as a commercial pilot, when he had been temporarily denied a US pilot's licence because of treatments for psychotic depression. For years, Lubitz had frequently been unable to sleep because of what he believed were vision problems; he consulted over 40 doctors, fearing he was going blind. Motivated by the fear that blindness would cause him to lose his pilot's licence, he began conducting online research about methods of committing suicide before deciding to crash Flight 9525.