Statements made by Mr. Spohr last week, in which he insisted that Mr. Lubitz had been fit to fly, are now coming back to haunt him. The Westdeutsche Zeitung, a newspaper covering the region that includes Düsseldorf, the German city to which the plane was flying, said Lufthansa's admission that it had known of Mr. Lubitz's mental health problems was "a helpless attempt to prevent company chief Carsten Spohr, with his fatal words '100 percent flightworthy,' " from appearing "as a liar ripe for resignation."
The possibility that a pilot was able to hide problems well enough to keep flying could also blemish one of Lufthansa's main selling points, its reputation for technical excellence and safety. Until last week, Lufthansa and its subsidiaries had not had a fatal flying accident in 22 years.
Since taking over as chief executive of Lufthansa in May, Mr. Spohr has responded to competition from no-frills airlines like Ryanair by putting more emphasis on Germanwings.
But questions are being raised about whether European procedures allow inexperienced pilots to have too much responsibility.
Mr. Lubitz had 630 hours of flight time when, according to investigators, he slammed the Airbus A320 into a mountainside. Mr. Lubitz had apparently locked the more experienced pilot out of the cockpit.
"How was it that this guy could have had only 630 hours and already be flying an A320?" asked Amy Fraher, a former United States Navy commander and United Airlines pilot. "It is a big, sophisticated aircraft with a lot of power and, in this case, 150 people on board."
"It troubles me," said Ms. Fraher, who also lectures at the University of Birmingham in Britain.
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"I see evidence that in the interests of cost-cutting, pilot training has become condensed" to just a few years, rather than the seven or eight years that was once the industry norm worldwide, she said. "Such an accelerated career path doesn't give young pilots time to become more professional and properly seasoned."
Others, however, doubt that Lufthansa's training practices played a role in the Germanwings crash.
"We have no evidence there has been cost-cutting on safety," said Christoph Drescher, general secretary of the European Cabin Crew Association, which represents flight attendants.
"The colleagues from Germanwings are very well trained," Mr. Drescher said. "The regulatory standards are upheld and exceeded."
Mr. Spohr, who has held numerous management roles in his 20 years at the Lufthansa group, including stints running its global airline partnerships and cargo businesses, is also a licensed Airbus A320 pilot.
He was the head of the main Lufthansa passenger business before assuming the role of chief executive.