Mitsubishi Aircraft and Mitsubishi Heavy Industries plan to announce the results of a new review of the MRJ’s program schedule by the end of this month, the companies said in a statement released Wednesday.

The announcement comes a little more than a month after the first MRJ prototype made its maiden flight from Nagoya Airport in Japan. Since then the companies flew the airplane at least two more times, on November 19 and November 27, and, according to Wednesday’s statement, flight testing continues.

The last program schedule called for certification in the second quarter of 2017, a date that remained unchanged following the last two delays to first flight. In April the companies announced a delay from the spring to “September or October” due to a need to review the structural strength of the ram air turbine (RAT) and address certain software bugs. Then, in the last week of October a problem with the MRJ’s rudder pedal forced the new regional jet’s manufacturer to reschedule first flight for the week of November 9. It finally took to the air on November 11, some four years after the original target date set at program launch in 2008.