Two key components in the flight test programme of China's first indigenously designed regional jet have not been completed, and this has led to the likelihood of a delay in the type certification and delivery of the aircraft.
Problems surfaced during the icing tests on the Commercial Aircraft Corp of China (Comac) ARJ21 in Urumuqi, Xinjiang province. Stalling speed tests have not begun yet either, said a source close to the programme, who spoke on condition of anonymity.
It is "uncertain" when these tests can be completed, and type certification will be awarded only when they are done, the source added.
"Comac is striving to receive type certification for the ARJ21 by year-end. But a delay in receiving type certification is a possibility. That means that a delay of first delivery for the aircraft is a possibility," said the source.
Launch customer Chengdu Airlines was due to receive the first ARJ21 by the end of 2011. Yu Luo, vice-general manager at the airline, said: "Comac has not informed us about changes in the delivery schedule of the ARJ21."
Chengdu Airlines is 48% owned by Comac and 40.9% owned by Sichuan Airlines.
Aircraft 104, which is involved in the icing tests, arrived in Urumqi on 27 March. The tests were due to be completed by the middle of 2011, but were not completed.
"There is a delay in the icing test as there is, at present, not enough natural ice in Urumuqi," said the source.
Static tests for the ARJ21 were completed on 14 April and crosswind tests on 24 May. Flutter testing on the ARJ21 started on 4 April, and was successfully completed in Xian on 18 August.
Representatives from the US Federal Aviation Administration (FAA), which is conducting a shadow certification of the programme and is assessing the Civil Aviation Administration of China's (CAAC) ability to assess the aircraft, were present for the flutter tests.
Comac has said it intends to apply for FAR 25 certification after the ARJ21 passes this shadow certification, so the aircraft can be marketed overseas.
Industry sources say the FAA had a role in pushing for further testing of the ARJ21, although a spokesman from the agency said he was unable to discuss the details of the shadow certification
"We are observing the CAAC as they certify the aircraft. We will observe testing, review certification data and observe meetings with the certification applicant; the CAAC defines the actual certification requirements," he added.