Two aircraft came dangerously close to each other on the runway in Kolkata this morning, in a narrow escape for hundreds of passengers.A Darbhanga-bound IndiGo aircraft, taxiing at the Kolkata Airport, hit a stationary Air India Express flight waiting for clearance to enter the runway. A part of the Air India Express aircraft's wing that was hit fell on the runway, while the IndiGo aircraft's wing was dented.