Air India A320 at Kochi on Aug 21st 2014, crew was radioed about smoke from engine, uncontained engine failure

Last Update: March 21, 2018 / 16:28:41 GMT/Zulu time

Bookmark this article

Incident Facts

Date of incident
Aug 21, 2014

Classification
Incident

Airline
Air India

Flight number
AI-47

Departure
Kochi, India

Destination
Delhi, India

Aircraft Registration
VT-ESI

Aircraft Type
Airbus A320

ICAO Type Designator
A320

Airport
Cochin International Airport, Cochin

Airport ICAO Code
VOCI

An Air India Airbus A320-200, registration VT-ESI performing flight AI-47 from Kochi to Delhi (India) with 169 passengers and 6 crew, was in the initial climb out of Kochi at about 21:00L (15:30Z), with a delay of one hour due to late arrival on the inbound flight, when the crew was radioed about smoke emanating from an engine (V2500). The crew stopped the climb and returned to Kochi for a safe landing about 15 minutes after departure.

The flight departed again about 45 minutes after landing and reached Delhi with a delay of 2 hours.

India's largest newspaper reported (in contradiction to all other reliable sources in India and about 10 hours after those sources) that the crew received an engine fire indication and shut the engine down. Then the paper exercised even prose poetry: "What made matters worse was that Kochi had bad weather at that time with thundery monsoon clouds covering the sky and strong winds blowing. However with a serious engine fire warning alarm, there was no time to jettison fuel. Captain ..... made one of the most difficult landings that any pilot can expect to make in his or her career. 'He climbed to about 3,000 feet and then returned to Kochi. The plane landed safely and he took it right to the terminal.'"

The Metars however show thunderstorms setting in at 23:00L (17:30Z) only and no strong winds at all. Needless to also point out a good number of impossibilities (e.g. jettison) and the contradiction in this report: that the aircraft was taken right to the terminal after this difficult landing with an ongoing serious fire alarm ...

On Sep 2nd 2014 the French BEA reported in their weekly bulletin quoting India's Accident Investigation Board, that during initial climb the crew declared emergency due to the failure of the right hand engine, shortly afterwards the engine fire indication came on and the aircraft returned to Kochi. Post flight examination showed the low pressure turbine stage 4 blades were partly sheared and some metal debris was found in the engine exhaust. Thrust reverser duct C was also found damaged. India's AIB rated the occurrence a serious incident and opened an investigation.

On Oct 14th 2014 the NTSB reported that the right hand engine (V2500) suffered an uncontained failure, the crew received an engine fire warning, shut the engine down and return to Kochi. Post flight visual inspection showed damage to the stage 4 low pressure turbine blades and metal debris in the exhaust as well as impact damage to the thrust reverser cowls consistent with an uncontained engine failure. India's AAIB is investigating the occurrence rated an incident (editor's note: not a serious incident), the NTSB have accredited a representative to assist the investigation.

On Mar 21st 2018 India's DGCA released their final report concluding the probable cause of the serious incident was:

Non adherence to the stipulated lapping procedure of cleaning and inspection of #4 seal plate during overhaul of engine # 2 resulted in blocking of anti-weep groove which allowed the oil to escape # 4 compartment and enter the HPT during sub-idle conditions. This oil seepage got ignited at increased engine power which eventually resulted into low cycle fatigue fracture to HPT 2nd stage air-seal.

The DGCA reported the aircraft was climbing out of Kochi's runway 27 about 65 seconds into the flight when the crew heard a loud bang and received a fire indication for the #2 engine. The crew performed the related checklist items, declared Mayday reporting a right hand engine fire. A passenger had seen fire from the #2 engine, notified cabin crew who in turn informed the flight deck. The fire indication ceased after working the checklists, the crew downgraded Mayday to PAN. The aircraft returned to Kochi for an overweight landing on runway 27 without further incident. A post flight inspection revealed metal debris in the engine exhaust as well as a puncture of the C-duct cowl. The engine fire had been confined to within the engine only.

The DGCA reported the damage was limited to the engine only and consisted of:

1. Outboard C Duct
- Outer Barrel found ruptured approximately 12 inches.
- Inner Barrel Burn mark & rupture observed
2. Inner C Duct
- Inner Barrel found burnt at 6 O’Clock position.
3. LPT (Low Pressure Turbine) stage 4 blades
- more than 20% of blades found damaged
- Most of the stage 4 NGV’s (Nozzle Guide Vanes) found damaged.
4. Overheating was observed on all the latches.
5. The turbine cooling air feed tube at 4 O’ Clock position found ruptured.
6. HPT (High Pressure Turbine) case between 1 & 3 O’ Clock position found ruptured open.
7. HPT case opened up and ruptured from 6 to 9 O’clock position shearing the 27 bolts on front side and 18 on rear side exposing entire HP turbine area.
8. All the turbine blades of stage 1 & 2 and stage 2 NGV’s found missing.
9. Turbine cooling air feed tube at 7 O’clock position found damaged.
10. HPT ACC duct found ruptured.
11. Lot of metal debris found stuck at different locations of the engine.
12. No. 2 shaft seized.
13. The No.1 shaft was found stuck and found difficult to rotate.
14. Fire bottles were found discharged.

The DGCA reported the engine had been last overhauled in March 2012 and had logged 8163 hours since. The engine had produced high EGT warnings repeatedly while mounted onto another aircraft and was subsequently moved onto VT-ESI.

Parts of the engine were sent to the NTSB for laboratory examination. The DGCA analysed:

No. 4 seal plate of engine # 2 (V0118) was analysed and it was observed that the weep grooves and holes of the seal plate were mostly blocked with lapping debris. In order to confirm the same, on site, lapping process review was carried out at IAC overhaul shop by IAC Personnel. IAC personnel performed lapping process demo using IAE provided V2500, #4 seal plate. After lapping, cleaning and preservation, it was observed that, seal plate weep grooves contained residual lapping debris or “slurry”. The slurry was analysed and was found to be matching with V0118 # 4 seal plate debris.

Both samples contained:
- Diamond particles- consistent with lapping paste.
- Barium- consistent with Aero-Shell 12, used for preservation.
- Iron particle size- consistent with lapping table.

The Anti weep circuit prevents the oil from escaping the compartment during sub idle conditions. V0118’s # 4 seal plate weep grooves and holes which were mostly blocked with lapping debris, allowed the oil release from #4 bearing compartment at the sub idle condition during start and shutdown.

The #4 seal plate lapping was carried out during the #2 engine overhaul and inadequate cleaning and inspection of Seal Plate after lapping resulted in most of the seal plate groove and holes getting blocked with lapping debris. This allowed the oil to escape # 4 compartment at engine sub-idle and getting ignited at increased engine power.

Metars:
VOCI 211930Z 00000KT 4000 HZ SCT012 FEW025CB OVC080 25/24 Q1006 NOSIG
VOCI 211830Z 08003KT 4000 TS SCT012 FEW025CB OVC080 25/23 Q1007 NOSIG
VOCI 211800Z 34003KT 4000 TS SCT012 FEW025CB OVC080 25/24 Q1007 NOSIG
VOCI 211730Z 33005KT 4000 TS SCT012 FEW025CB OVC080 25/24 Q1007 TEMPO RA
VOCI 211630Z 05003KT 4000 HZ SCT012 FEW025CB OVC080 25/23 Q1007 NOSIG
VOCI 211600Z 12006KT 4000 HZ SCT015 FEW025CB OVC080 25/23 Q1007 NOSIG
VOCI 211530Z 12006KT 4000 HZ SCT015 FEW025CB(N) OVC080 25/24 Q1007 NOSIG
VOCI 211500Z 10005KT 4000 HZ SCT015 OVC080 26/24 Q1007 NOSIG
VOCI 211430Z 11004KT 4000 -DZ SCT015 OVC080 26/25 Q1006 NOSIG
VOCI 211400Z 00000KT 5000 HZ SCT018 OVC080 27/25 Q1006 NOSIG