Description

On 29 February 2020, an Airbus A320 (VT-CCU) being operated by Air Asia (India) on a scheduled domestic passenger flight from Goa to Delhi as IAD778 and an Airbus A320 (VT-IAR) being operated by Indigo on a scheduled domestic passenger flight from Delhi to Chennai as IGO2124 came into close proximity in night IMC when on reciprocal tracks at less than the prescribed vertical separation whilst working the same radar control frequency. TCAS RA activation and compliance eliminated the collision risk and the minimum achieved separation was 0.5nm laterally and 600 feet vertically. 

Investigation

A Serious Incident Investigation was carried out by the Indian Aircraft Accidents Investigation Bureau (AAIB) by reference primarily to downloaded data from the Air Asia A320 CVR and FDR and recorded ATC radar data and communications with both aircraft.

It was noted that the Air Asia A320 flight crew consisted of a 35 year-old Captain who had a total of 5,426 hours flying experience which included 326 hours on type and a 32 year old First Officer who had a total of 2,283 hours flying experience, all but 271 hours of which were on type. The 50 year old Indigo A320 Captain had a total of 7,086 hours flying experience which included 3,427 hours on type and the 28 year old First Officer had a total of 1,791 hours flying experience, all but 201 hours of which were on type.