The MAKS 2017 Air Show is into its third day at Zhukovsky International Airport, Moscow Region.
The event, organized by the Russian Ministry of Industry and Trade and the Rostec State Corporation, will last through to July 23.
The 6-day exhibition shows of thousands of products and new designs, from nearly 800 companies, of 26 countries and regions.
The first three days are exclusively for research and development institutions, businesses and the press, while the other three days are open to the public.
The biennial event, founded in 1993, aims at displaying high-tech Russian aerospace products, and promoting business links with foreign partners.
According to the organizers, more than 73,000 professionals have signed up for the air show, with hundreds of thousands of visitors also expected.
The Commander of the Sri Lanka Air Force, Air Marshal KVB Jayampathy, visited the airshowe on the 21st.