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.