German aviation regulators say they were never made aware of Andreas Lubitz's mental health issues . Killer pilot Andreas Lubitz searched the internet for information on suicide and depression using the name 'Skydevil', it has emerged. The chilling username was discovered after analysis of a tablet computer found at his home, according to German newspaper Bild. Investigators also found search terms for disorders such as 'bipolar' and 'manic depressive'. In a separate development, it has emerged that European regulators warned Germany's aviation authority of inadequacies with its health check-ups in a regular review of air safety enforcement, the European Commission said. Its statement did not say when the review was carried out. But the Wall Street Journal said the Commission told Berlin in November 'to remedy the long-standing problems' - months before the Germanwings crash that killed all 150 people aboard. Meanwhile, the aviation authority, the Luftfahrtbundesamt (LBA), also said it did not know about Lubitz's medical background prior to the crash. Parent company Lufthansa said Lubitz told officials at an airline training school he had gone through a period of severe depression in the past, raising questions over whether medical checks of crew members by the safety regulators and airlines are rigorous enough. EU officials found that the LBA had a lack of staff, which could have limited its ability to carry out checks on planes and crew, such as medical checks, the Journal reported, citing two people familiar with the matter. It said it was unclear whether the deficiencies identified at LBA were factors in the crash, however. Vetting of airline crew is in the spotlight after the budget airline flight was crashed deliberately into by Lubitz. 'On the basis of EASA (European Aviation Safety Agency) recommendations, the Commission has addressed the issues to Germany to require compliance. 'Germany's replies are currently being assessed,' the Commission spokesman said in the statement, emailed out on Saturday. 'All EU member states have findings and this is a normal and regular occurrence. It is part of a continuous system of oversight: findings are followed by corrective action, similar to an audit process,' the Commission spokesman said, without specifying EASA's findings in Germany. The spokesman was not immediately available for further comment. The Germanwings Airbus A320 (above) crashed into a mountain at 430mph, killing all 150 people on board . A spokeswoman for the LBA said EASA's audits of national aviation authorities such as the LBA took place several times a year. She said the LBA had answered a single-figure number of criticisms levelled at it during the audits and those responses were now being assessed by EASA. Meanwhile, it has been claimed that Lufthansa did not inform  aviation regulators that Lubitz had struggled with depression. Sources at the Federal Aviation Office (LBA) said they were never made aware of the 27-year-old's mental health issues and only learned about them following the disaster. Lubitz perished in the crash alongside all those on board after locking his co-pilot out of the cockpit and deliberately accelerating into the French mountainside, prosecutors claim. His lengthy battle with depression was revealed afterwards when investigators carried out extensive checks on his record. However the LBA says it was never told of the observations made by doctors who had examined the 27-year-old in his 'earlier phase of serious depression'. The first black box voice recorder from the Germanwings flight that was recovered last week and revealed Andreas Lubitz deliberately crashed the plane. The second has now also been retrieved from the wreckage . German newspaper Welt am Sonntag quoted sources as having discovered his mental health issues three days after the crash by accessing his medical file at Lufthansa's Aeromedical Center. Records revealed he had been tested by doctors six times, the report claimed. Lufthansa declined to comment on its claims citing the ongoing investigation into the crash. Earlier the airline's chief Carsten Spohr said it was entirely unaware Lubitz had suffered any health issues that would have compromised his ability to fly. Last week it however conceded he had told his flight school of a previous bout of 'severe depression' in 2009. He was later given a medical certificate confirming he was fit to fly. Prosecutors claimed the pilot was diagnosed as suicidal several years before receiving his licence and that doctors had only recently concluded there was no evidence he wanted to harm himself. French emergency rescue services work at the crash site of the Germanwings plane where 150 people died . Lubitz had been signed off sick repeatedly in the days before the crash, with doctors notes found crumpled in his apartment following the disaster. Forensics teams are still working at the crash site, painstakingly recovering debris which they hope will aid investigations. It is not yet known whether the pilot was taking medication at the time of the crash, though data recovered from the scene revealed he had deliberately accelerated into the side of a mountain. He had previously been prescribed an anti-anxiety drug so strong that users are warned not to drive while under its influence. In the days before hand he had researched suicide methods and cockpit security online, all the while telling doctors he was not flying but on sick leave. Team talk: French gendarmes get ready to visit the crash site of the German Airbus A320 as part of the search operation in Seyne-les-Alpes .
Username found after analysis of a tablet computer found at his home .
Searched for information on 'bipolar' disorder and 'manic depressive'
German aviation authority said it was never made aware of pilot's illness .
Officials told local media they only discovered problems after the crash .