KUALA LUMPUR: More than a month after a Bo-105 helicopter went down in Long Lellang on Sept 8, claiming five lives, investigators have yet to reach a conclusion on what caused the crash.
The preliminary report released by the Air Accidents Investigation Bureau (AAIB) states the safety investigation remained ongoing, with the available factual data still only at a preliminary stage.
"Continuous fact-finding regarding flight operations, standard operating practices, and helicopter maintenance history will provide the necessary evidence to validate system defences and evaluate any latent conditions," the report read.
It found, at this preliminary stage, no fault with the helicopter's airframe, its maintenance nor the pilot.
However, it pointed out that the helicopter's engines were sent to the manufacturer's facility for further examination, with the powerplant investigation ongoing and any airworthiness implications for other engines of the same type yet to be established.
The report said an engineer from the engine manufacturer had participated in the on-site investigation as a technical expert representing the engine's state of design and state of manufacture.
"A detailed examination of the remaining wreckage was conducted, with particular attention given to the powerplant and its associated components.
"The recovered powerplant components were subsequently transported to the engine manufacturer's facility for further examination and analysis," it said.
The helicopter was fitted with two Rolls-Royce 250-C20B engines, with the No. 1 engine manufactured in 1989 and the No. 2 engine in 1976.
The AAIB said a 37-second ground-based video recording of the final portion of the flight showed a visible smoke trail and apparent flames in the vicinity of the area aft of the main gearbox with the origin, development and sequence of the fire remaining under investigation.
The report also said an initial examination of the accident site indicated that the helicopter sustained substantial damage from fire and ground contact.
The main wreckage and associated debris were found in the immediate vicinity of the crash site, while smaller items and components detached from the helicopter were recovered for further examination and analysis.
The report said the extent of damage to the airframe, engines, transmission system, flight controls and other helicopter components remained subject to further detailed examination with all recovered components and debris were transported to Miri for further analysis.
"A detailed wreckage examination will be conducted to establish the nature and extent of the damage and, where possible, the sequence and development of the fire and ground-contact damage," the report said.
The AAIB also said the helicopter was deemed airworthy at the time and held valid Certificates of Registration and Airworthiness.
It added that findings of the detailed wreckage examination and engine analysis will be included in the final report.
On Sept 8, a Flying Doctor Service Bo-105 helicopter carrying five people crashed near Long Lellang STOLport in Sarawak, killing all on board.
© New Straits Times Press (M) Bhd