WASHINGTON — U.S. regional airlines are preparing to ask the government to loosen 2013 pilot safety restrictions they say have unnecessarily caused a shortage of qualified flight crews.

The airlines, which perform about half of all air-carrier flights under contract to mainline operators, want to be able to hire pilots with fewer than 1,500 hours of flight time, according to the Regional Airline Association, their Washington trade group.

Just as regulations now allow pilots to qualify for the airlines with fewer hours after academic or military aviation training, the association wants to be able to hire pilots with less experience if they complete specialized training focusing on high-performance aircraft and airline operations, according to a draft of the group’s proposal provided to Bloomberg News on Wednesday.

“We agree wholeheartedly that first officers ought to be more experienced,” Faye Malarkey Black, president of the association, said in an interview. “Where we disagree is that you can use hours as a metric for experience.”

Regional carriers seeking pilot candidates have found that they often gain hours performing jobs such as flight instruction. While that has some value, it doesn’t help teach many of the skills required for airlines, Black said.

The changes sought by the group are still being finalized and it hasn’t decided how to propose them, she said. They must eventually go before the Federal Aviation Administration, which regulates the aviation industry.

The current 1,500-hour requirement was prompted by concerns over pilot performance in the last fatal accident involving a U.S. airline, the Colgan Air crash near Buffalo, New York, on Feb. 12, 2009. Pilots on that flight misunderstood a relatively benign cockpit warning and lost control, crashing into the ground and killing all 49 on the plane and a man on the ground. Colgan, a unit of Pinnacle Airlines Corp., is no longer in operation.

The regulation, mandated by Congress in 2010 legislation, has baffled airlines because both of the Colgan pilots had more than 1,500 hours. The results, they say, have been a shortage of qualified pilot applicants at lower-paying regional carriers.

The FAA allows pilots to qualify for the airlines with fewer hours — as little as 750 — if they have completed military flight training or gotten a degree from a qualified aviation college. The RAA wants to create a similar streamlined pathway based on completion of what it calls Air Carrier Enhanced training.

The RAA’s proposal was first reported in the Wall Street Journal.

The Air Line Pilots Association, the largest union for airline cockpit crews in North America, is opposed to any changes in the requirements, President Tim Canoll said.

“These important pilot training and qualification regulations, which emerged from a joint industry effort led by representatives of the regional airlines, must remain firmly in place to ensure the safety of air transportation in the United States,” Canoll said.