Photo taken on Oct. 13, 2018 shows model aircrafts with turbojet engines perform in the air during a contest in Rongcheng, east China's Shandong Province. A total of 12 teams from around the world compete in the air. (Photos: Xinhua)

Photo taken on Oct. 13, 2018 shows model aircrafts with turbojet engines perform in the air during a contest in Rongcheng, east China's Shandong Province. A total of 12 teams from around the world compete in the air.

Photo taken on Oct. 13, 2018 shows model aircrafts with turbojet engines perform in the air during a contest in Rongcheng, east China's Shandong Province. A total of 12 teams from around the world compete in the air.

Photo taken on Oct. 13, 2018 shows model aircrafts with turbojet engines perform in the air during a contest in Rongcheng, east China's Shandong Province. A total of 12 teams from around the world compete in the air.

Photo taken on Oct. 13, 2018 shows model aircrafts with turbojet engines perform in the air during a contest in Rongcheng, east China's Shandong Province. A total of 12 teams from around the world compete in the air.

A contestant controls his model aircraft with turbojet engine during a contest in Rongcheng, east China's Shandong Province, Oct. 13, 2018. A total of 12 teams from around the world compete in the air.

Photo taken on Oct. 13, 2018 shows model aircrafts with turbojet engines perform in the air during a contest in Rongcheng, east China's Shandong Province. A total of 12 teams from around the world compete in the air.