The redevelopment of Terminal 1, commissioned in 1964, is being undertaken primarily to address structural and safety concerns. Mumbai Around 91 per cent of international passenger traffic at Mumbai's Chhatrapati Shivaji Maharaj International Airport (CSMIA) will remain unaffected during the redevelopment of Terminal 1, with 39 of the 50 international airlines continuing operations at the airport under the Summer 2027 schedule.