October 26, 2012
Credit: Image: Comac
The internal target for certification of Comac’s 90-seat ARJ21 regional jet has been delayed again, to 2014 from the previously scheduled mid-2013, says a program official. Development therefore is now likely to last 12 years, with six years of flight testing. A key reason for the latest delay is slow progress in flight testing. Engineers also are attending to avionics bugs and modifying the landing gear, one of many issues arising from changes elsewhere in the design.
Another official working on the ARJ21 says that he knows of no formal decision to delay to 2014 but that, given the current state of development and flight tests, the aircraft cannot be certified before that year. It is quite likely to be ready in 2014, however, he adds.
While struggling to get the ARJ21 certified, Comac is considering both updating the aircraft, whose technology is aging even before airlines begin using it, and launching another regional airliner, say industry officials. In the end, the two ideas might be merged. The idea of improving the ARJ21, most obviously with new engines, has been looked at since about the time of the first flight in 2008.
The other project is sometimes called the New Regional Aircraft. It would follow the C929 widebody airliner that Comac proposes building once it completes development of the C919, a 158-seat narrowbody planned for certification in 2016 and intended to challenge the Airbus A320 family and the Boeing 737.
Among the ARJ21’s developmental problems is one emphasized by Comac internally: Coordination with the Civil Aviation Administration of China (CAAC) has not always been smooth. CAAC officials need to attend every test flight, but bringing together the schedules of the aircraft and the personnel from different organizations has not been easy and has delayed progress.
The CAAC also has been learning to improve its performance in certification programs, and not only in relation to the objective of ensuring safety. It has picked up experience in working more smoothly with Comac and suppliers. For example, it has not always been prompt in executing tasks such as inspecting materials and equipment, says a program official, adding that it can be expected to perform better in the future.
The growing experience of CAAC and Comac is one reason not to think that the ARJ21’s problems necessarily foreshadow similar delays in the much larger and more important C919 effort. In working on the C919, Comac has come to understand much more about commercial aircraft design and development than its predecessor, Avic Commercial Aircraft Co., knew during the early work on the ARJ21, the officials point out. The company knows more partly because of mistakes made in ARJ21 development.
Those errors have included a structural weakness—the ARJ21’s wing failed a strength test. One change leads to others, some at the insistence of the CAAC, such as modifications being made to the landing gear to meet revised load calculations. Sometimes the program has moved too slowly to address emerging issues, says an official.