Factual Information
On 15 July 2019, an Indigo Airbus A320-271 NEO aircraft, registration VT-ITU, was operating scheduled flight 6E-162 from Goa to Ahmedabad. The aircraft had no reported abnormalities during previous flights that day. The flight crew consisted of two ATPL holders, with the pilot-in-command having 13,276 hours total flying experience and the co-pilot 2,036 hours.
Sequence of Events
The aircraft departed Goa at approximately 1008 UTC. While climbing through 26,000 feet, the crew heard a loud bang followed by an ECAM warning indicating an engine stall on engine number 1. The crew executed the Quick Reference Handbook (QRH) procedure, retarding the thrust lever of engine 1 to idle. Engine parameters showed N1 vibrations at 10, N2 vibrations at 6.7, and exhaust gas temperature (EGT) exceeding 900°C. Due to these abnormal parameters, the crew shut down engine 1 in flight. After completing all ECAM actions, the crew obtained clearance from Air Traffic Control (ATC) and diverted back to Goa, landing safely at 1120 UTC. The aircraft vacated the runway and parked at the bay; passengers disembarked normally. There was no fire and no injuries to occupants.
Damage to Aircraft
Post-flight visual inspection of engine 1 revealed damage to the low-pressure turbine (LPT) 3rd stage blades. Borescope inspections further identified:
- Scratch marks on several blades of high-pressure compressor (HPC) stage 8 and slight indentations on HPC stage 7 blades.
- Two blades of high-pressure turbine (HPT) stage 1 with tip edge damage; two blades at bottom dead center coated with oil film.
- Low-pressure compressor (LPC) assembly showed only oil and dirt accumulation at stage 1 inlet root area.
- LPT stage 3 blades fully damaged; several blades of LPT stage 2 damaged; LPT stage 1 blades had nicks and residual material debris.
- Combustion chamber and HPT nozzle guide vanes showed only ceramic metal coating loss at some locations, no burn-back observed.
Personnel and Aircraft Information
Both pilots held valid ATPL licenses and medical certificates. The aircraft, an Airbus A320-271 NEO powered by Pratt & Whitney PW1127G-JM engines, was owned by Jackson Square Aviation Ireland Ltd. and operated by Inter Globe Aviation Ltd (IndiGo). It had a valid Certificate of Airworthiness. The serious incident was investigated by the Aircraft Accident Investigation Bureau (AAIB) under Rule 11 of the Aircraft (Investigation of Accidents and Incidents) Rules, 2017.