Experts and engineers emphasized that China's first homegrown airliner, the C919, which debuted Monday, was developed using a domestic design protected by intellectual property rights, dismissing criticism that the aircraft was a mere assembly from foreign components.

Rolling off the final assembly line in Shanghai on Tuesday, the new aircraft began to receive both attention and criticism, especially after news site guancha.cn pointed out that only four out of 18 main components of the C919 are provided by domestic manufacturers.

Chen Yingchun, vice chief designer of the C919, said that China did not pay any money to foreign companies for the airplane's design, and that the aircraft's design, aerodynamic configuration and system integration were all completed and tested by the manufacturer in China, the People's Daily reported.

Liu Jimei, a Beijing-based aviation expert, told the Global Times that aircraft manufacturing is the integration of both components and systems. "It takes a lot of time and resources to combine all the components and make them work coherently, which China has successfully done."

"Some core technologies of the C919 are independently developed, such as its full-time full-authority fly-by-wire control system and advanced active control technology," Liu added.

The C919's engine was developed by foreign companies, but that does not mean that the airliner was assembled from foreign components, Wang Guangqiu, a vice president of the Commercial Aircraft Corporation of China Ltd (COMAC), the manufacturer of C919, told The Beijing News.

There is no need to build an aircraft behind closed doors, it's better to cooperate with other manufacturers, Luo Wenzhong, a regional general manager at Honeywell International, told news portal the paper.cn. The New Jersey-based Honeywell supplies the C919 with auxiliary power units, flight controls, wheels and brakes, as well as its navigation system, according to media reports.