A glossary of the terms in AAIB's report on the crash

The Aircraft Accident Investigation Bureau's preliminary report into Air India Flight 171 is dense with aviation terminology that helps explain how investigators determined both engine fuel cutoff switches “transitioned from RUN to CUTOFF position one after another with a time gap of 01 sec.” Understanding these technical terms is crucial to grasping what happened during those fatal 32 seconds after takeoff.

- HT Correspondent

The key technical terms that matter.

EAFR (Enhanced Airborne Flight Recorder):

The report centres on data from the aircraft's two EAFRs, which combine traditional “black box” functions into single units recording both flight data and cockpit voice communications. The forward EAFR provided the critical timeline showing exactly when fuel switches moved and engines began losing power.

Fuel Control Switches - RUN vs CUTOFF: