GERMAN prosecutors revealed the “significant discovery” made at Germanwings co-pilot Andreas Lubitz’s home was a sick note for the day of the crash.

The shocking evidence came from the search of Lubitz’s homes, in two German cities, for an explanation of why he deliberately crashed the Airbus A320 into the French Alps.

Prosecutors found “torn-up and current sick leave notices” in Lubitz’s home, suggesting he was receiving medical treatment but hid his illness from his employer and colleagues.

Pilot hid illness from employers

While investigators did not specify what illness Lubitz had, German media reports he needed ongoing assessments for severe depression, BBC reports.

Dusseldorf prosecutors said in a statement that “interviews on this subject and the evaluation of medical records will take several more days”, and that the outcome would be made public “once reliable evidence is available”.

“Documents with medical contents were confiscated that point towards an existing illness and corresponding treatment by doctors,” the London Telegraph reports prosecutors saying. “The fact there are sick notes saying he was unable to work, among other things, that were found torn up, which were recent and even from the day of the crime, support the assumption based on the preliminary examination that the deceased hid his illness from his employer and his professional colleagues.”

Duesseldorf University Hospital said in a statement that Lubitz had been a patient there over the past two months and last came to the hospital for “diagnostic evaluation” on March 10. It declined to provide details about his condition but denied German media reports that it had treated the 27-year-old pilot for depression.

The hospital says it has submitted Lubitz’s patient record to prosecutors in Duesseldorf, where he lived.

Authorities did not find a “suicide note or a confession”, or any evidence that the co-pilot’s actions may have been motivated by “a political or religious background”.

Officers had on Thursday combed through a flat Andreas Lubitz kept in Duesseldorf as well as the house where he lived with his parents in the small western town of Montabaur.

Relationship crisis led to breakdown

The news comes following revelations the captain, Patrick Sonderheimer, used an axe to break down the cockpit’s armoured door when he was locked out on the day of the crash.

This could not be immediately confirmed, but a spokesman for Germanwings confirmed to AFP that an axe was on board the aircraft. Such a tool is “part of the safety equipment of an A320,” the spokesman told Bild.

Lubitz reportedly suffered a major breakdown following a “serious crisis in his relationship” that left him heartbroken and distraught, the German paper Bild reported.

According to The Telegraph in the UK, Lubitz was engaged to be married next year, but had broken up with his fiancee. It is understood that the 27-year-old was struggling to cope after the relationship failed.

The theory emerged hours after The Guardian reported Lubitz stopped his training to be a pilot six years ago because he was suffering from “psychological problems”.

A Spiegel reporter, Matthias Gebauer, tweeted that a friend of Lubitz said he had “burnout or depression” in 2009 and took a break from his pilot training.

A report, quoted from German daily Bild, said the Lufthansa flight school in Phoenix designated Lubitz at the time as “not suitable for flying”.

In a press conference, Lufthansa CEO Carsten Spohr confirmed that Lubitz had taken several months off work without disclosing why, but said he was considered mentally and physically fit to fly.

He said Lubitz had passed all psychological tests required to begin training and underwent regular physical examinations.

Searching for clues

Specialist officers spent three and a half hours searching Lubitz’s top-floor flat and were later seen removing three boxes.

Markus Niesczery of Dusseldorf Police told the Daily Mail: “We wanted to search to see if we could find something that would explain what happened.”

“We have found something which will now be taken for tests. We cannot say what it is at the moment but it may be a very significant clue to what has happened,” Mr Niesczery said.

No other details were released by local officials however.

Evidence crash was deliberate

CNN also reported that transponder data revealed the autopilot on the doomed flight was reprogrammed by someone in the cockpit to change the plane’s altitude from 38,000 feet to 100 feet, according to Flightradar24.

Prosecutors say Lubitz deliberately crashed the passenger plane, killing 150 people.

Marseille prosecutor Brice Robin said the co-pilot crashed the plane “intentionally” and locked the captain out of the cockpit on Tuesday.

Mr Spohr said that it appears the captain punched in the emergency number into the cockpit door to gain entry, but the co-pilot deployed the five-minute override.

Mr Robin said there is no indication this was an act of terrorism, but stopped short of declaring it suicide, saying only it was a “legitimate” question to ask.

On the question of suicide, Mr Spohr said: “We can only speculate what might have been the motivation of the co-pilot. In a company that prides itself on its safety record, this is a shock. We select cockpit personnel carefully.”

Piecing together a private life

Lubitz lived with his parents in Montabaur and also kept a flat in Dusseldorf, a Germanwings hub, according to Montabaur mayor Gabriele Wieland.

The town of Montabaur published a news release on Thursday expressing sympathy with the family, although it did not name Lubitz.

At the house believed to be his parents’, the curtains were drawn and four police cars were parked outside. Police kept the media away from the door of the Montabaur home.

Neighbour Johannes Rossmann said Lubitz appeared to be in good health and was a regular jogger. He described the pilot as calm and low-key.

“I do not believe he killed himself and claimed other people’s lives,” the 22-year-old Rossmann said. “I can’t believe it until it is 100 per cent confirmed.”

‘A dream to fly’

Lubitz was also identified by a flight club at which he was a member, according to the Wall Street Journal.

“Andreas became a member of the club as a youth to fulfil his dream of flying,” the Luftsportclub Westerwald said in a death notice on its website. “He began as a gliding student and made it to become a pilots on an Airbus 320.”

“He fulfilled his dream, the dream he now paid for so dearly with his life,” the club said.

“He was happy he had the job with Germanwings and he was doing well,” glider club member Peter Ruecker told the Independent. “He gave off a good feeling.”

Ruecker said that he remembers Lubitz as “rather quiet but friendly” when he first showed up at the club as a 14 or 15-year-old.

Club chairman Klaus Radke said he rejected French prosecutors’ conclusion that Lubitz put the Germanwings flight intentionally into a descent when the pilot had left the cockpit.

“I don’t see how anyone can draw such conclusions before the investigation is completed,” he said.

Ruecker said Lubitz also trained in Phoenix, Arizona, and had a girlfriend but did not have many more details about his life. A recently deleted Facebook page bearing Lubitz’s name showed him as a smiling man posing in front of the Golden Gate Bridge in California.

Lubitz joined Germanwings in September 2013 straight from the Lufthansa Flight Training School in Bremen, the London Telegraph reports. He had about 630 flight hours at the time of the crash.

Lubitz first worked as a flight attendant, according to Thomas Winkelmann, the Greenwings managing director, who said there was nothing unusual in the results of Lubitz’s training.

A 2013 article in the Aviation Business Gazette reported the US Federal Aviation Administration’s (FAA) inclusion of Lubitz in the prestigious FAA Airmen Certification Database, for having “met or exceeded the high educational, licensing and medical standards established by the FAA”.

“FAA pilot certification can be the difference between a safe flight and one that ends in tragedy,” the journal says.

How the horror unfolded

Mr Robin outlined Lubitz’s actions for the press in a chilling account of the plane’s last minutes.

“For the first 20 minutes of the flight, the pilots spoke in a normal way, you could say cheerful and courteous,” Mr Robin said. “We heard the flight commander prepare the briefing for landing at Dusseldorf and the response of the co-pilot seemed laconic. Then we heard the commander ask the co-pilot to take the controls.”

According to Bild and Europe1, Captain Sonderheimer was married and the father of two children. He had more than 6000 flight hours, mostly on Airbus jets.

Mr Robin said the co-pilot’s responses, initially courteous, became “curt” when the captain began the mid-flight briefing on the planned landing of the Germanwings flight which crashed in France, killing 150 people.

Photo of Andreas Lubitz from now-deleted Facebook profile page. Cached here: http://t.co/FvX202bX1A pic.twitter.com/D1UF0VlxMn — Sam Schlinkert (@sts10) March 26, 2015

Mr Robin told a press conference the actions that took the plane down occurred during the last eight minutes of the flight, the Guardian reports.

While the co-pilot was alone at the controls, he initiated the descent of the plane, selecting the altitude in such a way that could only have occurred deliberately.

“Forty-eight hours after the crash … the interpretation for us is that the co-pilot deliberately refused to open the door of the cockpit to the flight commander, and pushed the button causing a loss of altitude.”

“We heard several calls from the flight commander asking for access to the cockpit,” Mr Robin said. “There was a visual and audio interphone and he identified himself. There was no response from the co-pilot.

We are shaken by the upsetting statements of the French authorities. 1/3 — Germanwings (@germanwings) March 26, 2015

“We heard at the same time the sound of a seat being pushed back and the sound of a door closing.”

Mr Robin said Lubitz could be heard breathing right up until the point of impact, suggesting he had not lost consciousness. However, he failed to respond to increasingly desperate calls from the commander trying to break down the cockpit door, or to air traffic controllers.

Australia reviews cockpit safety procedures

Australian aviation authorities will review cockpit security procedures in the wake of the horrific Germanwings’ crash.

Deputy Prime Minister and Minister for Infrastructure and Regional Development Warren Truss said the review would consider whether any changes were needed to regulations that allowed pilots to be left alone in the cockpit for brief periods.

Already several overseas carriers have changed their policy, to ensure no-one is ever left alone in the flight deck.

Since the September 11 attacks, US carriers have been required to have a flight attendant take the pilot or co-pilot’s place when they leave the cockpit for a toilet break, or other reason.

“Careful consideration needs to be made following thorough investigation to ensure that altering current procedures does not open other potential vulnerabilities,” Mr Truss said.

“Our two major international and domestic airlines are undertaking their own safety and security risk assessments of cockpit procedures following the recent tragedy.”

Mr Truss said Australian travellers should have confidence in the strict safety regulations already in place to safeguard passengers.

“We take a preventive, layered approach to aviation security,” he said.

“Airline pilots are psychologically tested as part of their recruitment process.

“Pilots must also undergo at least annual medical, including mental health checks under Civil Aviation Safety Authority licence requirements.”

A Qantas Group spokesman said they were “monitoring the information coming out of the French investigation and considering if any changes to our existing safeguards are needed”.

“This includes discussions with regulators,” he said.

The European Union says it is studying whether to make airlines keep two crew members in the cockpit at all times after the French Alps crash. German airlines have agreed to a new safety rule to keep two crew members in an airplane’s cockpit at all times, the aviation association BDL has announced.