After two aborted test flights in as many days tied to a problematic air-conditioning system, Japan's first locally built passenger jet was back for checks and fixes amid delays to a program aimed at challenging the dominance of Brazil's Embraer SA and Canada's Bombardier Inc.

Mitsubishi Aircraft Corp., the builder of the Mitsubishi Regional Jet, will make a decision on resuming test flights to the United States after the problem has been fixed, Spokesman Kenichi Takemori said by phone from Nagoya Monday. The company has delayed delivery of the aircraft at least four times, with ANA Holdings Inc. scheduled to receive the first MRJ in mid-2018.

Mitsubishi Aircraft, a unit of Mitsubishi Heavy Industries Ltd., is trying to break the regional-jet duopoly of Embraer and Bombardier. The MRJ, which can seat as many as 92 people, is getting a boost as Bombardier focuses on building C Series jets that will be able to carry as many as 160 passengers, rather than renew its lineup of planes with fewer than 100 seats.