Of the 13 cases, nine were investigated and reason found out was error by air traffic controller or pilot error. The other four cases were under investigation, Minister of State for Civil Aviation K C Venugopal told the Lok Sabha in a written reply.
Airprox is an unplanned event in which two aircraft come close to each other breaching the standard separation distance. However, there is no risk of collision.
"Based on investigation, ATCOs and pilot proficiency checks are being carried out regularly, modernisation of ATC services to include conflict warning in the system to assist ATCOs, coordination procedures of handling over from one unit to another have been laid out," he said.