A fierce blaze fuelled by safety facility deficiencies at Long Lellang Short Runway Airport in Ulu Baram, Sarawak, was the primary cause of death for five individuals in a helicopter crash, with all victims dying from severe burns rather than impact forces.

The Air Accident Investigation Bureau (AAIB) of the Transport Ministry revealed the findings regarding the cause of death and shortcomings in the rescue operation in a preliminary report published today.

Pathological and medical investigations confirmed that the pilot and four passengers aboard the Bolkow BO105 S helicopter, operated by Layang-Layang Aerospace Sdn Bhd, did not perish from the impact of the crash on the runway.

"Instead, (they died) as a result of being engulfed in flames and suffering critical burns before they could be rescued," the report stated.