Created Friday, Jun 12th 2026 09:57Z, last updated Friday, Jun 12th 2026 09:57Z
An Air India Airbus A319-100, registration VT-SCJ performing flight AI-776 from Mumbai to Kolkata (India) with 115 passengers and 6 crew, was departing Mumbai's runway 27 when the left hand engine (CFM56) emitted two loud bangs during rotation for takeoff, during initial climb a severe burning odour was observed in cockpit and cabin, passengers observed flames from the left hand engine. All indications in the cockpit remained normal however. As a precaution the crew decided to return to Mumbai for a safe landing on both engines.
The DGCA reported that on the inbound flight to Mumbai, AI-775, the aircraft had encountered a bird strike to the left hand engine, parameters remained normal, maintenance examined the aircraft and found no damage, maintenance scheduled a borescopic inspection of the engine was scheduled within 25 flight hours/10 flights and released the aircraft according to aircraft maintenance manual.
India's DGCA released their final report concluding the probable causes of the incident were:
The failure of Engine No. 1 was attributed to engine stall during the take-off roll, just prior to lift-off. While the shop investigation could not definitively establish the root cause, DFDR data and the damage observed on the HPC blades were consistent with stall condition.
Amongst the findings the DGCA stated:
The technical analysis involved reviewing the DFDR data, in which CFM identified two probable stalls based on N1 and EGT values. The stalls were short and recoverable, with no significant variations in oil pressure or vibration signatures. The engine stall message was inhibited during certain flight phases, which may explain the absence of stall messages in PFR.
Thee DGCA analysed:
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The shop report of the Engine no. 1 reveals that there was no definitive evidence of FOD or DOD. Also during the Black Light Inspection; No bird remains, or organic matter was found on HPC blades. This rules out the possibility of any bird remains in the Engine due to bird strike in the previous sector leading to this incident.
In view of above, serviceability of the aircraft was not a contributory factor to the incident.
Operational Aspect:
During rotation of the incident flight, AI776, while getting airborne, the flight crew and the passengers heard loud bang twice. After takeoff, a severe burning smell was reported inside the cockpit and the cabin. Passengers also reported flames/fire from the Engine No. 1. However the indications in the cockpit were normal and all parameters were found to be within limits. Crew decided to return to Mumbai and carried out overweight landing. Aircraft landed safely.
As per the CVR recoding, the flight crew experienced burning smell in cockpit but did not notice any fire. Fire was reported to be observed by the passengers. The decision to return back was taken on time and an overweight landing was carried out by the crew and all the checklist were carried out by the flight crew. The action of the crew was found to be satisfactory.
In view of the above, the operation aspects has no bearing on the incident.
Engine Shop Investigation
The engine was sent to Jet Engine Overhaul Complex (JEOC), M/s Air India Engineering Services Ltd. (AIESL), Delhi for detailed root cause analysis of the engine failure. Engine Inspection revealed no damage in the Low Pressure Compressor (LPC) modules from booster stage 2 to 5. There was no evidence of soft ingestion and missing hardware in the HPC during the inspections, including when the HPC top case was removed. Hence there was no definitive evidence of FOD or DOD. During Black Light Inspection; No bird remains, or organic matter found on HPC blades. PFR submitted by Air India showed no Stall message however, the type of damage observed on HPC blades is similar to that observed on engines which have been inducted in shop earlier due to stall. The tip curls on the HPC blades confirms the most probable cause of the event as engine stall.
Feedback received from Airbus & CFM
The Engine 1 Stall was not reflected in the Post Flight Report (PFR) or Electronic Centralized Aircraft Monitor (ECAM) due to Flight Warning Computer (FWC) takeoff phase inhibition.
The technical analysis involved reviewing the DFDR data, in which CFM identified two probable stalls based on N1 and EGT values. The stalls were short and recoverable, with no significant variations in oil pressure or vibration signatures. The engine stall message was inhibited during certain flight phases, which may explain the absence of stall messages in PFR.
Technical Aspect:
The TSM task for Stall of Engine 1 or 2 in Flight was followed by the Engineer and as per the TSM task, troubleshooting procedure should be carried out for cases as defined in the title and for cases if crew reported audible engine stall while no ECAM warning ENG 1(2) STALL was set. This procedure covers stall conditions that occurred at N2 speed at or above idle. Flight crew had reported that flight encountered two loud bangs, burning smell, and flames from Engine no. 1 which justifies that engine stall conditions were present during the take off and same had been confirmed by CFM as per the DFDR review. The TSM task was followed and damage observed on HPC blades which is prominent to the engine stall conditions.
