First delivery of the Commercial Aircraft Corporation of China (Comac) ARJ21 regional jet is likely to be delayed by up to a year or more, after problems surfaced during the flight testing programme.

Sources close to the programme, who spoke on condition of anonymity, said the airframer is not likely to deliver the first aircraft to launch operator Chengdu Airlines by end-2011 as scheduled.

A Comac spokesman was not able to comment on the reported delay. Chengdu Airlines was uncontactable for comment.

Among the problems faced by the airframer is the incorrect positioning of aircraft probes which resulted in inaccurate readings during flight testing, said sources.

The programme has also not completed its icing tests, said a source, adding that this makes it difficult for the ARJ21 to receive its type certificate by year-end.

"There isn't much time left, the icing tests were supposed to be completed in the first half of this year but they were not," he added.

Sources said 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, has played a part in pushing for further testing of the ARJ21.

A FAA spokesman said the agency cannot discuss details of the shadow certification as it is still active. "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," said the spokesman.

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.

Source: Air Transport Intelligence news