PETALING JAYA, Aug. 12 -- The operator of a Bell 206L4 helicopter that crashed in Bentong, Pahang, on February 6 failed to follow safety procedures for hot refuelling, the Air Accident Investigation Bureau (AAIB) has found in its preliminary report.

In the report published on its website, AAIB said that video from the day before the crash showed the aircraft hovering with its rotor blades running while moving closer to a ground engineer standing beneath the main rotor disc.

This, it said, was in breach of rules requiring crew to wait at a safe distance until a thumbs-up signal from the pilot.

To note, hot refuelling is the process of filling an aircraft's fuel tanks while its engine is running.

The AAIB deemed that unsafe actions by b...