CHENGDU -- A fleet of Chinese Y-9 aircraft has conducted an airdrop drill over an island in the South China Sea, according to a statement from the People's Liberation Army (PLA) Air Force.

The aircraft have flown thousands of kilometers from China's southwestern Sichuan Province and have proven to be combat ready after the first long-distance sea training, said the statement.

The fleet performed the drill without artificial marks, weather data or guidance from a command center, and circled around the island before returning the same day.

The Y-9 medium-lift transport aircraft has conducted drills in deserts, plateaus and at sea, experiencing severe weather conditions such as sand storms, thunder and gales.

It has successfully completed various tasks including air-ground joint exercises and heavy equipment airdrops, the statement said.