Severe weather, delayed re-routing likely caused May IndiGo incident: DGCA

Severe weather and non-timely action in re-routing the aircraft clear of weather were the probable causes that led to IndiGo's Delhi-Srinagar flight incident where the aircraft's nose radome was damaged on May 21, according to the probe findings by aviation regulator DGCA.

On May 21, IndiGo's A321 neo aircraft VT-IMD while operating flight 6E-2142 from Delhi to Srinagar encountered severe weather, including hail, during cruise. After landing in Srinagar, the aircraft radome was found damaged, Minister of State for Civil Aviation Murlidhar Mohol told the Rajya Sabha on Monday.

The incident was investigated by the Directorate General of Civil Aviation (DGCA).

"The investigation has revealed that severe weather existing en-route and non-timely action in re-routing the aircraft clear of weather was the probable cause of the occurrence," the minister said in a written reply.

On May 23, two days after the incident, DGCA had said IndiGo flight crew initially attempted to return but as they were close to the thunderstorm cloud, they decided to penetrate the weather.

"Subsequently, they encountered hailstorm and severe turbulence. Crew chose to continue at the same heading to exit the weather by the shortest route towards Srinagar," it had said in a statement. 

While in a thunderstorm cloud, the regulator had said warnings of Angle of Attack fault, Alternate Law protection lost, backup Speed scale unreliable were triggered.

"Due to updraft and downdraft encountered by the aircraft the Autopilot tripped and aircraft speed had wide variations. As a result, Maximum Operating Speed/Maximum operating Mach (VMO/MMO) warnings and repeated stall warnings were triggered," it had said.

On May 21, the flight crew had sought permission to enter Pakistan airspace to avoid turbulence but the request was rejected.