Air India B787 GEnx-1B In Flight Shut Down After Maintenance Error 5 Years Earlier (VT-ANW)
On 4 August 2023 Air India Boeing 787-8 VT-ANW suffered un-commanded In Flight Shut Down (IFSD) of its No 1 GE GEnx-1B engine 9 minutes after take off, forcing a return to Mumbai Airport.
The Indian Aircraft Accident Investigation Bureau (AAIB) published their safety investigation report in May 2025. This was the source of the illustrations below.
Note: This article was prepared a week a go but publication was delayed as AAIB published their Preliminary Report on 11 July 2025 on the unrelated fatal accident involving Air India 787-8 VT-ANB at Ahmedabad on 12 June 2025.
The Safety Investigation
A post-incident engine strip released the release of an High Pressure Compressor (HPC) Stage 10 blade was the cause of the IFSD and Electronic Engine Control (EEC) auto-restart attempts were unsuccessful due to distress from the blade’s release.
There are two locking lugs for each HPC stage. These secure the blades in a circumferential fashion to prevent blade release from the load slot. During installation a set screw is torqued, raising the locking lug into the locking slot in the spool, but this depends on the correct positioning of the lug in the slot.
Investigation found that “the LH locking lug was installed out of the lock slot and the RH locking lug was installed partially inside the lock slot”.
This improper installation caused the release of the blade.
The last maintenance action on the HPC stage 10 blades had occurred at the GE Evergreen
Engine Services (GEEVES) facility in Taiwan in 2018.
Unfortunately, but perhaps understandably due to the time having passed, the Indian AAIB report goes no further to understand the circumstances of the 2018 maintenance and the human factors that may have affected the maintenance.
Safety Resources
You may also find these Aerossurance articles of interest:
- B787 GEnx Fan Shaft Failure (Air India 2012)
- Uncontained PW1524G Failure During CS100 Certification Testing
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- NTSB Recommendations on JT15D Failure to Meet Certification Bird Strike Requirements
- CFM56-7 HPC Titanium Fire Due to VSV Maintenance Assembly Error (United Boeing 737-924)
- B767 Fire and Uncommanded Evacuation After Lockwire Omitted
- Japanese Jetstar Boeing 787 GEnx-1B Engine Biocide Serious Incident
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- T-Bolt Trouble: Unrecorded Maintenance on US HEMS BK117C2/H145 and Loss of TR Pitch Control
- Fatal $16 Million Maintenance Errors
- CHC Sikorsky S-92A Seat Slide Surprise(s)
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- USAF RC-135V Rivet Joint Oxygen Fire
- The Missing Igniters: Fatigue & Management of Change Shortcomings
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- Crossed Cables: Colgan Air B1900D N240CJ Maintenance Error
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- Dash 8 Q400 Return to Base After Pitot System Contaminated By Unapproved Test Kit Lubricant
- Dash 8 Q400 Control Anomalies: 1 Worn Cable and 1 Mystery
We have written several general articles related to maintenance safety:
- Professor James Reason’s 12 Principles of Error Management
- How To Develop Your Organisation’s Safety Culture
- Aircraft Maintenance: Going for Gold?
- Critical Maintenance Tasks: EASA Part-M & -145 Change
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