Visitors look at a Bell 505 helicopter during the international helicopter industry exhibition HeliRussia 2020 in Moscow, Russia, on Sept. 16, 2020. The exhibition is held here from Sept. 15 to Sept. 17. (Photo by Alexander Zemlianichenko Jr/Xinhua)

A girl is seen inside a helicopter during the international helicopter industry exhibition HeliRussia 2020 in Moscow, Russia, on Sept. 16, 2020. The exhibition is held here from Sept. 15 to Sept. 17. (Photo by Alexander Zemlianichenko Jr/Xinhua)

Visitors wearing face masks talk in front of a helicopter during the international helicopter industry exhibition HeliRussia 2020 in Moscow, Russia, on Sept. 16, 2020. The exhibition is held here from Sept. 15 to Sept. 17. (Photo by Alexander Zemlianichenko Jr/Xinhua)

People visit the international helicopter industry exhibition HeliRussia 2020 in Moscow, Russia, on Sept. 16, 2020. The exhibition is held here from Sept. 15 to Sept. 17. (Photo by Alexander Zemlianichenko Jr/Xinhua)

People visit the international helicopter industry exhibition HeliRussia 2020 in Moscow, Russia, on Sept. 16, 2020. The exhibition is held here from Sept. 15 to Sept. 17. (Photo by Alexander Zemlianichenko Jr/Xinhua)

A Ka-32 helicopter is seen at the international helicopter industry exhibition HeliRussia 2020 in Moscow, Russia, on Sept. 16, 2020. The exhibition is held here from Sept. 15 to Sept. 17. (Photo by Alexander Zemlianichenko Jr/Xinhua)

People visit the international helicopter industry exhibition HeliRussia 2020 in Moscow, Russia, on Sept. 16, 2020. The exhibition is held here from Sept. 15 to Sept. 17. (Photo by Alexander Zemlianichenko Jr/Xinhua)