BEIJING - A military expert said construction of China's second aircraft carrier is normal and the scale of China's aircraft carrier development is much smaller than that of the United States and even India.

Aircraft carriers can help China better defend world peace and stability and play its role as a responsible developing power, Zhang Junshe, a researcher with the People's Liberation Army's (PLA) Naval Military Studies Research Institute, told 81.cn, the official website of the PLA Daily.

A spokesman for China's defense ministry said Thursday that China's second carrier, with a displacement of 50,000 tonnes, is conventionally powered and will employ a ski-jump design for warplanes to take off.

As a latecomer, China needs to build conventionally powered carriers first in order to gain experience, and then build nuclear-powered ones according to the situation, said Zhang, noting that the design and manufacturing processes are completely domestic, with no foreign help.

Zhang added that future Chinese carriers will be fitted with catapults for fighter jets to take off on deck, but the process will be gradual since catapult take-off involves more complex technology.

He noted that, compared with China's first carrier, the Liaoning, the second carrier will have more mature technology and performance, with better coordination between its systems and high anti-interference capacity.

While the main purpose of the Liaoning is research, testing and training, Zhang said the second carrier will be able to carry out combat operations more quickly. "Its missions will possibly include combat readiness on duty and other normal operations, including humanitarian rescue and disaster relief."

A report from the PLA Daily in late December said China's carrier forces, mainly those operating the Liaoning, had made considerable progress in fighting capacity this year, with more fighters parked on the carrier and more flights handled by the vessel.

The Liaoning was refitted from a former Soviet ship known as Varyag. It was delivered to the Chinese Navy on Sept. 25, 2012.