PUTRAJAYA - The helicopter that crashed on April 4 in Semenyih seemed to have lost its left horizontal stabiliser moments before it plunged to the ground, said investigators probing the crash that killed six, including Rompin MP Tan Sri Dr Jamaluddin Jarjis.
In a preliminary report presented by Transport Minister Datuk Seri Liow Tiong Lai here yesterday, it was revealed that the aircraft likely sustained some damage when it made an unscheduled landing on a school field in Muadzam Shah, Pahang, to offload an unnamed passenger.
"The left landing gear sunk about 20 inches deep (51cm) into the ground, causing the helicopter to tilt more than 13 degrees to the left.
"This may have caused the left horizontal stabiliser to be damaged," Liow told a press conference as he unveiled the findings of the Air Accident Investigation Bureau of Malaysia on what could have happened to the 15-year-old Eurocopter Dauphine 9M-IGB helicopter.
The investigators do not have the complete picture as a crucial piece of evidence is still missing - the left horizontal stabiliser has not been found until today.
"We suspect it got detached about five seconds before the helicopter dived," said Department of Civil Aviation (DCA) director of flight operations Datuk Yahya Abdul Rahman, who heads the investigation team.
Yahya said the horizontal stabiliser was still attached to the helicopter when it took off from Rompin.
"It must have been weakened by the vibration during the flight and fallen off," he said, adding that finding the stabiliser was important to help pinpoint the cause of the crash.
The helicopter was travelling from Pekan, Pahang, to Subang when it crashed at a rubber plantation in Semenyih, at 4.52pm.
Also killed were the principal private secretary to the Prime Minister Datuk Seri Azlin Alias, Kedah businessman Datuk Tan Huat Seng, pilot Capt Cliff Fournier, Jamaluddin's bodyguard Mohd Raskan Seran, and a female Kyrgyz national by the name of Aidana Baizieva.
During the investigation, DCA was assisted by BEA, the French authority responsible for safety investigations into civil aviation incidents, while Britain's Air Accident Investigation Branch was involved in the downloading of data from the cockpit voice recorder (CVR) and flight data recorder (FDR).
The 22-page report said preliminary analysis of data by BEA revealed that the aircraft encountered some "extreme load factor" several seconds before the end of the recorded data associated with extreme attitude (a condition where the helicopter was in, or headed towards, dangerous parameters not usually encountered in normal conditions).
"The extreme attitude was due to negative load factor by very fast pitch down motion consistent with the result of lost of the left horizontal stabiliser without any pilot action."
According to the CVR data, the pilot was aware that his helicopter sustained some damage during the awkward landing, although he did not know exactly where or how bad it was.
In his conversation with Aidana, he said: "We went all the way to the belly, it's not good.
"It's definitely not normal for the wheels to go down into the ground that far. It's definitely not good to tip like that," Fournier added.
Investigators said a more detailed analysis of the CVR/FDR is still needed, while flight simulations are being planned with Airbus Helicopters, manufacturer of the Eurocopter.
DCA may push for more regulations for private aircraft, stating that pre-flight preparations must include risk assessment of not just the route, but also landing points, while its flight manifest could be made compulsory.
"Pilot is to avoid landing at any location on discretion of the passenger," stated the report, which can be found at www.mot.gov.my.