Air India B787 GEnx-1B In Flight Shut Down After Maintenance Error 5 Years Earlier
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.
