The case of the JetBlue captain who came unglued at 35,000 feet has focused attention on what some aviation experts say is a flimsy system for detecting psychological problems in pilots.
During required checkups every six months or one year, airline pilots are subjected to a battery of physical tests, but the doctor usually doesn't ask about their mental state, experts and pilots say. And many pilots would probably hesitate to tell the truth, for fear it would be a career-ender.
"It's very clear to every pilot that the moment you say yes, you've had an issue, they're going to deny your license," said John Gadzinski, a captain for a major airline and an aviation consultant.
Still, there appears to be little interest in beefing up the examinations because mental breakdowns in the cockpit are extremely rare.
"Of the tens of thousands of employees (airlines) have, there are a couple that lost it," said Robert Francis, a former vice chairman of the National Transportation Safety Board. "That's hardly enough evidence to lead to new regulations."
On Tuesday, Clayton Osbon, the 49-year-old captain of a New York-to-Las Vegas flight, started ranting about a bomb aboard and screamed, "They're going to take us down!" A co-pilot locked him out of the cockpit and guided the plane to an emergency landing in Amarillo as passengers wrestled Osbon to the floor. He was carried off the plane and taken to a hospital. JetBlue said he suffered a "medical situation."
The outburst came weeks after a distraught American Airlines flight attendant was taken off a plane at the Dallas-Fort Worth Airport for getting on the public address system and rambling about 9/11 and her fears the plane would crash. She, too, was hospitalized.
JetBlue Airways CEO Dave Barger said on NBC's "Today" show that he has known Osbon personally and that he is "a consummate professional," with nothing in his past to indicate he would be a risk on a flight.
Osbon, a pilot for JetBlue since 2000, was charged Wednesday with interfering with a flight crew. The airline suspended him.
"Clearly, he had an emotional or mental type of breakdown," said Tony Antolino, a security executive who sat in the 10th row of the plane and tackled the captain when he tried to re-enter the cockpit. "He became almost delusional."
Airlines and the Federal Aviation Administration strongly encourage pilots to assert themselves if they think safety is being jeopardized, even if it means going against a captain's orders. Safety experts have studied several cases where pilots deferred to more experienced captains with tragic results.
The FAA requires all airline pilots to pass a medical exam at least once a year _ every six months if they're older than 40, like Osbon. The medical tests are given by FAA-approved doctors who are supposed to consider psychological health in evaluating pilots. Also, the pilot's application for a certificate _ his license to fly _ asks whether the pilot has mental disorders or substance-abuse problems or has attempted to commit suicide.
In 2011, 1.5 percent of all pilots tested failed their physical. That figure includes cargo and private pilots, not just airline employees.
Treatment for mental illness does not necessarily end a pilot's career. In 2010, the FAA decided that pilots treated for mild to moderate depression could return to flying if they improved with treatment and remained stable for at least a year.
Many pilots say, however, that the doctors often skim over the psychological questions.
"I've never had a psychological part of the exam," Gadzinski said. Another captain for a major airline, who spoke on condition of anonymity to protect his job, said his own doctor keeps two files _ one with accurate records, another for the FAA.
Merely asking a pilot about his mental health isn't a very effective technique for predicting whether he might have a breakdown during a flight, said Richard Bloom, an administrator at Embry-Riddle Aeronautical University who holds a doctorate in clinical psychology.
"It's too easy to answer," Bloom said. "There is a great opportunity for deception, just like with many people at job interviews."
Bloom and several other experts said incidents like Tuesday's are so rare that more screening might not improve security or be worth the expense.
However, some, including Francis and another former NTSB member, James Hall, said the episode could have ended in disaster if Osbon had had a gun. They called for a review of a 10-year-old anti-terrorism program under which airline pilots who get special training are allowed to carry guns.
According to FAA records, Osbon passed a medical exam in December. Citing privacy rules, the FAA declined a request by The Associated Press to release the exam results and Osbon's answers to questions on the FAA application.
A 2006 study by the FAA of post-mortem toxicological evaluations of 4,143 pilots _ mostly small-plane pilots _ killed in accidents between 1993 and 2003 found that 223 were using mood-altering drugs such as antidepressants.
But only 14 of the pilots who tested positive for the drugs reported a psychological condition on their medical forms, and only one reported using a mood-altering drug on the forms. None of the pilots determined to have used neurological medications had reported that on their medical applications.
Incidents in which pilots have become mentally incapacitated during a flight are rare.
In 2008, an Air Canada co-pilot was forcibly removed from the cockpit and restrained after having a breakdown on a Toronto-to-London flight.
In 1999, U.S. investigators determined that the co-pilot of an EgyptAir plane deliberately crashed into the Atlantic but said they couldn't determine his motive. All 217 people on board were killed.
In 1996, a co-pilot of a passenger jet broke into a sweat on a flight from England to Italy and told the pilot he was afraid of heights, forcing the Maersk airlines jet with 49 passengers on board to make an emergency landing.
In 1982, a Japan Airlines jet plunged into Tokyo Bay after the captain, who had once been grounded for mental illness, reversed some of the engines. The co-pilot and flight engineer struggled but couldn't regain control of the plane. The crash killed 24 of the 174 people on board.
The FAA medical exam form: http://apne.ws/HnkiY4
Koenig reported from Dallas; Lowy from Washington.