Mitsubishi Aircraft says the anomalies detected on its MRJ regional jet prototype are not due to faulty systems, but that it is nonetheless working to “uncover the cause” that forced it to abort two attempts to fly the aircraft to the US late last month.

In response to queries from FlightGlobal, Mitsubishi says the ferry flights had to be aborted when anomalies were detected in the signals generated by sensors monitoring the aircraft’s air management systems. These are supplied by UTC Aerospace Systems, according to Mitsubishi's website.

It stressed that the air management system did not stop and operated as it should. The issue, however, lies in the signals generated by the sensors.

“We are now working to uncover the cause and getting closer to problem solving. We will make a final decision after having taken corrective measures, and conducted ground testing and flight tests,” it adds.

A spokesperson tells FlightGlobal that the issue with the sensor was not recognised during flight tests before the ferry flight. Tests conducted on FTA-2 however do not throw up the sensor issue, which indicates that the problem is not with the system or parts.

After the first ferry flight was aborted on 27 August, Mitsubishi said that it found an issue with the sensor of the air management system, and that the result from function tests was good after the sensor was replaced.

A flight on 28 August was however again cut short after it detected a similar issue.

Mitsubishi says the issue had no impact on flight safety but that it decided to bring the prototype back to its Nagoya home base, because it wanted the aircraft to be “in perfect condition” for the 8,000km journey.

It would not say when its ferry attempt will occur.

Asked how the push back in its ferry flights would affect the programme’s schedule, Mitsubishi says that "as of now, there is no change in the delivery schedule".

“In managing 2,500 hours of flight time, we will plan out the allocation of testing among our four flight test aircraft for maximum effectiveness,” it adds.

Mitsubishi was working towards an August timeline to bring the FTA-1 to the US, ahead of its fourth quarter schedule, so as to accelerate its flight test programme and provide a buffer for technical or certification issues that could arise.

It is targeting to certify the MRJ in early 2018 and to deliver the aircraft to launch customer All Nippon Airways in the middle of the year.

Source: Cirium Dashboard