New Delhi: In a harrowing incident on November 17, two IndiGo aircraft narrowly avoided a collision as they ascended from Delhi’s Indira Gandhi International Airport. The aircraft, an Airbus A321 with registration VT-IUO and an Airbus A320 (VT-ISO), experienced dangerously close vertical and lateral proximity, breaching minimum separation standards.
The Aircraft Accident Investigation Bureau (AAIB) is spearheading a probe into the incident, categorizing it as a “serious incident”. According to AAIB’s preliminary report, at the closest point, the vertical separation was a mere 400 feet, with lateral separation shrinking to 1.2 nautical miles. Despite the breach, there were no injuries or damages reported on either aircraft.
Standard aviation protocols mandate a minimum vertical separation of 1,000 feet and a lateral separation of 5 nautical miles during flight. IndiGo has refrained from commenting on the incident pending the outcome of the investigation.
AAIB’s initial findings reveal that the A321 departed from Runway 27 at 12:31 PM and veered off course towards the takeoff path of Runway 29 Right, contrary to instructions to climb to 8,000 feet. Simultaneously, the A320 en route to Raipur received clearance and took off from Runway 29 Right, leading to the perilously close encounter.
Both aircraft received Traffic Alert and Collision Avoidance System-Resolution Advisory (TCAS-RA) alerts, prompting corrective action to avert a potential collision. TCAS-RA provides pilots with real-time instructions to navigate away from potential conflicts, ensuring airspace safety.
While the preliminary report offers insights into the incident, the ongoing investigation timeline remains undisclosed. AAIB is meticulously examining cockpit voice and flight data recorders, operational manuals, radar data, and statements from flight crew and air traffic controllers to ascertain the sequence of events leading to the close call.