Operations at Mumbai's Chhatrapati Shivaji Maharaj International Airport's main runway resumed this evening after a SpiceJet plane that had skidded off was finally cleared after four days. <br />'' <br />'' The closure of the main runway had caused over 300 flight delays/cancellations since Monday night. Operations at country's second busiest airport were forced to shift to the secondary runway which has a capacity to handle only up to 35 aircraft movement per hour as against 48 of the main runway.<br />