Mitsubishi Aircraft will use seven test aircraft for the certification of its MRJ regional jet.
Five aircraft will be used for flight tests, while another two will be used for static strength tests and fatigue strength tests, Mitsubishi tells Flightglobal Pro.
"With the five flight test aircraft, we plan to spend about 2,500 flight hours for various tests," it adds.
Gearing up for its fourth quarter 2013 first flight target, the airframer is now conducting the sub-assembly of the first flight test aircraft. The first part of which involves putting together the centre wing box, fuselage and wings.
Fabrication of parts for the other test aircraft have also started, says Mitsubishi.
"The next big step will be the final assembly that will start at Mitsubishi Heavy Industries's Komaki South plant," it adds.
In reaction to speculation that the first flight of the MRJ will likely be delayed, the airframer would only say that no changes have been made to its first flight and first delivery targets. It also plans to obtain type certification of the jet by first delivery.
Mitsubishi adds that since its detailed design, no changes have been made to the MRJ, even though it continues to gather improvements for the production process, maintenance, and reduce weight and costs.
Going by what Mitsubishi's chairman and chief executive Hideo Egawa had told Flightglobal Pro in an interview at Farnborough last year, it appears that the company could be cutting it close to its schedule.
Egawa had said that the first test aircraft is expected to roll out in early 2013, and that the aircraft will be ready at least four months before it conducts its first flight.
Mitsubishi has firm orders for 165 MRJs and 160 options, with delivery to its launch customer scheduled for 2015.