Tire prints are visible on the flight deck of China's second aircraft carrier Type 001A after it returned to the Dalian Shipyard from its sixth sea trial on Friday. Photo: IC

China's second aircraft carrier returned to the shipyard on Friday after completing its sixth sea trial, which might have featured warplane takeoff and landing tests for the first time, reports said.

The first domestically developed aircraft carrier Type 001A moored back to its dock at the Dalian Shipyard in Dalian, Northeast China's Liaoning Province Friday morning, six days after the vessel set out for its sixth sea trial on May 25, news website wenweipo.com reported on Friday.

Photos provided on Chinese image service provider IC on Friday showed tire prints of warplanes on the carrier's flight deck.

This is an indication that the second aircraft carrier could have undertaken its first fighter jet takeoff and landing test, the report said.

When aircraft land on the carrier, they usually leave tire prints. When China's first aircraft carrier Liaoning undertook similar tests, such prints were also spotted on its flight deck.

Another possibility is that carrier-based aircraft conducted touch-and-go landings, which means the aircraft may have landed on the flight deck but took off without stopping, a Chinese military expert who asked not to be named told the Global Times on Friday.

Either way, tire prints indicate the aircraft carrier is one step closer to its combat readiness and commissioning, the expert said.

In the previous five sea trials, the Type 001A successfully tested its main functions, including the propulsion system, combat and supply capabilities, China Central Television reported in April. No tire prints were spotted after those trials.

Military experts previously told the Global Times that the Type 001A will be commissioned into the People's Liberation Army Navy within the year. The wenweipo.com report predicted that might come as soon as next month.

It is not yet known if the second carrier will make another sea trial, or if it is waiting to join naval service directly.