A helicopter is seen during sunset time of the final day of Aero India 2017 at Yelahanka Air Force base, in Bangalore, India on Feb. 18, 2017. (Xinhua/Stringer)
A helicopter is seen during sunset time of the final day of Aero India 2017 at Yelahanka Air Force base, in Bangalore, India on Feb. 18, 2017. (Xinhua/Stringer)