WASHINGTON (AP) — Airline co-pilots would have to meet the same experience threshold required of captains, the first increase in four decades, under regulations proposed Monday by the Federal Aviation Administration.

The proposal would increase the minimum number of flight hours required to fly for a commercial airline to 1,500 for all pilots. Captains already must meet that threshold, but co-pilots need only 250 hours.

The proposal is the first increase in the requirement to become a co-pilot since 1973, when the F.A.A. raised the minimum number of hours to 250 from 200.

Co-pilots would also need a “type rating” specific to the airliner they plan to fly, another requirement that has applied only to captains. That would mean additional training and testing.