Pilots will need more cockpit training to become fully certified first officers for U.S. passenger and cargo airlines.
The safety change ordered by Congress and imposed by the Federal Aviation Administration on Wednesday mainly grew out of a 2009 commuter plane crash and takes effect as attention focuses on pilot training issues around Saturday's Asiana Airlines crash in San Francisco.
Co-pilots must complete 1,500 hours total time as a pilot under the new rules, which take effect August 1. Previously, first officers were required to have only a commercial pilot certificate, which requires 250 hours of flight time.
The rule also requires first officers to undergo new training and testing specific to the planes they fly.
"The rule gives first officers a stronger foundation of aeronautical knowledge and experience before they fly for an air carrier," FAA Administrator Michael Huerta said in a statement.
Newer pilots for U.S. airlines today typically fly for regional carriers, which operate smaller jets domestically and feed bigger airlines at their hubs. Most airline cockpit crews are comprised of two pilots -- a captain and a first officer.
The crash of a Colgan Air commuter plane in February 2009 outside Buffalo that killed 49 people prompted Congress to order the new rule change as well as updated regulations on crew scheduling and rest.
Families of Colgan crash victims pushed hard for lawmakers to act.
The National Transportation Safety Board (NTSB) blamed pilot error and inadequate training for that accident.
Questions around pilot training are also at the center of the first major U.S. airline accident since the Colgan tragedy -- the one on Saturday involving an Asiana Boeing 777 that crash-landed at San Francisco International Airport.
The pilot at the controls, a captain, had only limited time in 777s although he was experienced at flying other Boeing and Airbus jetliners, the NTSB said, adding that it would review training and other records as part of its probe.
Pilots of international airlines are not required to follow FAA training standards.