An ARJ21-700 aircraft takes off from Beijing Capital International Airport on Dec 28. Guan Jianfei / for China Daily

Domestic aircraft is first assessed for airworthiness by local authority

Guo Yanghui, an engineer for aircraft manufacturer Commercial Aircraft Corp of China, has lived in Xi'an for four years.

His son was born in the capital of Shaanxi province in August. The 32-year-old plans to move his family to a new apartment he bought in Shanghai, where COMAC has its headquarters, but he doesn't know when they can go home.

"I work where my aircraft is located," he said.

Guo is a member of COMAC's outfield test team for the Advanced Regional Jet of the 21st century, or the ARJ21, the first regional jet developed by China.

The aircraft, which holds up to 90 seats, made its maiden flight in 2008.

Both its manufacturer and the Chinese aviation authorities have been working since to certify the plane's airworthiness.

Guo and his colleagues provided technical support for the ARJ21's airworthiness certification tests in Yanliang district in Xi'an, which is known as a hub for Chinese aircraft manufacturing.

On Dec 30, the Civil Aviation Administration of China certified the ARJ21. COMAC's outfield test team will now be reduced from more than 200 members to about 100 in line with the manufacturer's plans.

It is the first time the CAAC has awarded a domestically made aircraft an airworthiness certification based on the CCAR-25-R3 regulation, which is equivalent to international airworthiness standards for large passenger aircraft.

Airworthiness is a measure of an aircraft's suitability for safe flight, and receiving certification means the ARJ21 meets the authority's safety requirements for a passenger aircraft.

The certification is also seen as a green light for the aircraft to enter the market.

The authority examines the aircraft's safety on behalf of passengers, said Shen Xiaoming, head of the airworthiness certification center of CAAC's East China bureau and director of CAAC's ARJ21 airworthiness certification team.

Just as with other crucial departments, the experts and engineers who work on the certification should be responsible for the aircraft's airworthiness for its full operating life.

But without previous experience, the authority did not even know how to design the tests, he said, as the regulations only specified desired outcomes.

Thus, it took a long time for the authority to design every test from scratch, Shen said.

"The authority's capital and resources for airworthiness certification are limited," he said.

CAAC has two airworthiness certification centers, with the Shanghai center assessing transport aircraft based on the CCAR-25 regulation, while the center in Shenyang, Liaoning province, assesses general aviation aircraft based on the CCAR-23 regulation.

Currently, 275 employees of CAAC work on airworthiness certification, Shen said.

Generally speaking, certifying an aircraft's airworthiness requires a team of 80 employees, but CAAC has fewer than 70 people assessing the C919, a domestic large passenger aircraft, he said.

The government is aware of the issue and is working to enlarge the airworthiness team.

The Shanghai center spent 13 million yuan ($2.09 million) sending five test pilots to train in the United States. The authority will also train six to 10 test pilots for C919 airworthiness certification, Shen said.

"The authority's airworthiness force will be strengthened in the future."

But CAAC still needs time to build its team as experts need to understand both airworthiness and aircraft design, Shen said.

The completion of the ARJ21's certification shows that the Chinese authorities are capable of examining passenger aircraft airworthiness, Shen said.