10 July 2001, TUE
Expert says pilot cut voice recorders
Australian expert in SilkAir trial says flight recorders were not faulty and pilot could have pulled out of dive
By Tan Ooi Boon
ASSISTANT NEWS EDITOR
AN AVIATION expert yesterday said that both the voice and flight-data recorders of the ill-fated SilkAir MI 185 were not faulty, but had been switched off by the pilot.
Mr Job is critical of the Indonesian report. He is pictured with senior counsel Michael Khoo (right). -- WANG HUIFEN
Mr Macarthur Job, an Australian flight safety consultant, said it was not possible for both recorders to simply stop working within six minutes of each other.
Because both devices were powered by the same electrical components, he ruled out power failure, because this would have resulted in both machines stopping simultaneously.
While the Indonesian crash investigators suggested the stoppages could be due to 'broken wires', he said the probability of this affecting only the two recorders was 'so highly improbable that it could not be considered a realistic possibility'.
Instead, he said, the stoppages could be explained by someone pulling the circuit breakers for both recorders manually.
The opinion of the expert - the third to be called by the five crash-victim families who are suing SilkAir - echoed the finding of the United States' National Transportation Safety Board (NTSB).
It concluded that MI 185 crashed in Palembang on Dec 19, 1997, as a result of 'intentional pilot action'.
Mr Job, who has reviewed about 3,000 air crashes around the world, noted that the NTSB had been very critical of the report by the Indonesian investigators from the National Transportation Safety Committee (NTSC).
'It is as though the NTSC determined, despite the outcome of an impartial, expert technical investigation, to produce a report that refused to draw an obvious conclusion,' he said in his written statement to the court.
He noted that the final minutes of the voice recording showed sounds of seat movement and the removal of a seat belt.
Agreeing with the US experts, he said the sequence was consistent with MI 185 plane captain Tsu Way Ming preparing to leave the cockpit.
Noting that a panel directly behind the captain's seat contained the circuit breakers for both recorders, he said that it was evident that Capt Tsu would have been in the best position to stop the recorders manually.
Mr Job said there was other evidence in the NTSB report which pointed to a deliberate crash.
He noted that Capt Tsu, a former aerobatic pilot in the Singapore air force's Black Knights, did not make any attempt to recover from the steep dive the plane took from 35,000 feet that ended in the crash, even though it was possible and he had ample time to do so.
The Indonesians had implied that the crash could have been caused by the flight crew's failure to recover from an 'unexpected unusual flight upset'.
But Mr Job agreed with the NTSB that such a conclusion was not supported by evidence. The trial continues.
Call to view cockpit
ONE of the lawyers in the SilkAir hearing in the High Court yesterday suggested that the presiding judge get into a Boeing 737 cockpit.
Senior Counsel Michael Khoo made that proposal so that Justice Tan Lee Meng could find out, first hand, what might have happened in the cockpit as the plane was spiralling down.
'A picture speaks a thousand words,' he said.
Mr Khoo, who is representing the families of six people who died in the 1997 crash, then asked if SilkAir could arrange for this.
The airline's lawyer, Mr Lok Vi Ming, said that his client would like to help, but could not, as SilkAir no longer had any Boeing 737 aircraft in its fleet.
It also did not have any access to a Boeing 737 flight simulator in Singapore, he said.
He added that perhaps Mr Khoo could arrange for the group to use the cockpit of a Boeing 737 belonging to another carrier.
After the exchange, Justice Tan said only that he would continue to hear the evidence.
UNANSWERED QUESTIONS IN OFFICIAL REPORTS
Judge raps probe teams for 'alarming gaps'
By Karen Wong
THE High Court judge hearing the SilkAir crash testimony yesterday criticised both the Indonesian-led crash probe team and the US National Transportation Safety Board (NTSB) for crucial gaps in their reports.
Justice Tan Lee Meng noted that both teams had failed to explain why the falling SilkAir plane lost radar contact after descending below 19,500 feet above sea level.
'Notwithstanding three years of investigations, nobody came up with an answer. Is this not alarming?' he asked.
Mr Macarthur Job, the plaintiffs' third expert witness, agreed that it was.
'The report did not even cover what I thought was relevant about the pilot,' the judge continued, referring to Captain Tsu Way Ming. 'Now we find out that important matters such as the missing radar sweep had not been covered. What else has not been covered?' he asked.
Last week, Justice Tan asked two of the expert witnesses for the plaintiffs, Captains John Laming and Maurie Baston, what a co-pilot could do if the pilot wanted to crash the plane.
The experts replied that it depended on who won the fight for control of the plane.
He then asked for a physical comparison of the two pilots. He was told yesterday that Captain Tsu was 1.75 m and weighed 79 kg, while First Officer Duncan Ward was 1.77 m and 73 kg.
Regarding the missing radar signals, the court heard how the airport's radar device makes a sweep every eight seconds.
In the case of SilkAir MI 185, it detected a signal at 35,000 feet and then a final signal 32 seconds later when the plane was at 19,500 feet, shortly before it plunged into the Musi River, near Palembang, Indonesia.
The fact that the radar failed when the plane dropped below 19,500 feet could have indicated that the plane's two transponders had stopped working.
The plaintiffs say the plane had either broken up or that the wires had been made faulty due to the rapid descent.
But the airline contends that there may have been a progressive electrical failure, which could also explain why the cockpit voice and flight data recorders stopped working six minutes apart from each other. Justice Tan then asked Mr Job why the issue of the missing radar signals had not been raised by the two previous expert witnesses, as well as the Indonesian National Transport Safety Committee (NTSC) and the NTSB.
'We've spent so much time on the issue of the radar sweep that escaped the attention of the NTSC and NTSB,' said the judge, expressing his concern. 'And here we are finding out new facts.'
