India’s aviation sector is poised to become more competitive after authorities granted initial approval to two new airlines to start operations in the country, in a move that will further challenge the duopoly of IndiGo and Air India. The expansion comes as the sector was rattled by a series of setbacks this year, including IndiGo’s massive flight cancellations earlier this month and the crash of an Air India plane in Ahmedabad in June. On Tuesday, Civil Aviation Minister Kinjarapu Ram Mohan...