Before stepping into the cockpit of a commercial jetliner for the first time, pilots have racked up hundreds of hours in the air, usually at the controls of small planes.
In coming years, they may get most of their flight experience without ever leaving the ground.
The international organization that sets the world's aviation regulations has adopted a standard that could alter the nature of pilot training. In essence, prospective co-pilots will be able to earn most of their experience on the ground.
The move is designed to allow foreign airlines, especially those in Asia and the Middle East that face pilot shortages, to more quickly train and hire flight crews. The United States isn't expected to adopt the new rules any time soon, but international pilots trained under the new standards will be allowed to fly into and out of the country.
"In a simulator, you have pride at stake," said Dennis Dolan, president of the International Federation of Air Line Pilots' Associations, which has raised questions about the new standard. "In a real airplane, you have your life at stake."
Officials at the International Civil Aviation Organization, which is setting the new standards for pilot licensing, said the role of simulators has grown substantially in most airline training programs. Airlines often train co-pilots for new aircraft only in simulators, without flying; such a co-pilot's first flight on the new plane is with paying passengers on board.
The new rules apply only to co-pilots of commercial planes. Captains, in charge of those aircraft, must have hundreds more hours of flight experience. But co-pilots perform many of the same duties as captains.
The new standards will allow people to become a co-pilot on a jetliner with about 70 hours of flight time and 170 hours in simulators. Other licenses require about 200 hours of flight experience.
In the United States, a co-pilot of a commercial plane must have at least 250 hours of experience, some of which can be earned in simulators, federal regulators said.
Each country sets its own licensing requirements, which can be tougher than the ICAO standards. The Federal Aviation Administration is not expected to adopt the new license in this country. But experts say that if the number of people learning to fly in the United States continues to drop, the FAA could be forced to adopt the rules.
The new standards allow airlines to more properly train and supervise young pilots before they develop bad habits at flight school or flying alone, industry officials said, adding that the devices better prepare pilots for today's sophisticated cockpits.
"Those hours flying solo in a single-engine piston airplane, they do us no good at the airlines, and we can't monitor the pilots," said Christian Schroeder, an official with the International Air Transport Association, a trade group that represents airlines. "We are training a better-qualified and safer pilot this way."
However, safety experts and pilots groups said pilots gain invaluable "white-knuckle" experience during hundreds of hours of flight time in real planes. Flight crews also learn the intricacies and pressures of dealing with air-traffic controllers in congested air space — conditions that are hard to replicate in simulators, the experts and pilots said.
In addition, no one has studied whether simulators can safely replace early flight experience, said Cass Howell, chairman of the department of aeronautical science at Embry Riddle Aeronautical University in Florida.
"There is no objective proof that this will be just as safe a method of training," Howell said. "At this point, nobody knows if this is an effective training method."
The graphics displayed on cockpit windows are so advanced pilots can watch baggage carts rumble across taxiways and see wisps of clouds rush past their windows and snow drift across tarmacs. Full-motion simulators — giant boxes atop moving legs — can toss crews around in bad turbulence and even duplicate the thud-thud-thudding of a jet streaking toward takeoff.
Pilots use the devices to practice difficult approaches, engine failure recovery and extreme weather response, all too dangerous for real flight training. U.S. simulators help pilots adjust to new aircraft and keep them up on safety measures.
Pilots Ron Davis, left, and Jeff DePaolis use an Airbus 320 simulator on the ground to work through scenarios that would be far too dangerous to summon in a real airplane while in flight.