Flight testing of the Mitsubishi MRJ has resumed, following grounding of the four-airplane test fleet on August 21. During a test flight about 90 miles west of Portland, the left Pratt & Whitney PW1200G geared turbofan on MRJ FTA-2 experienced an uncommanded shutdown, and the flight test crew diverted to Portland International Airport. After an engine swap, the test pilots flew FTA-2 to the flight test base at Grant County Airport in Moses Lake, Washington.

FTA-4, which had been flying out Phoenix-Mesa Gateway Airport in Mesa, Arizona, resumed flight testing there on September 6, according to a Mitsubishi spokesman. “We were able to review and inspect the engines on FTA-4 with the Pratt & Whitney team and determine that the aircraft was able to resume flight tests,” he told AIN. “We are still in the process of determining the exact cause of the malfunction in the engine on FTA-2. We will re-inspect the other engines in our flight-test fleet and phase them into resumed testing once the appropriate measures are implemented, and pending [Japanese] JCAB approval.”

The fly-by-wire MRJ was expected to complete flight testing by the end of 2018, with certification planned in 2019. First delivery to All Nippon Airways is scheduled in 2020.