Pilot Or 737 Rudder? Both Eyed In Crash
Seattle Times Staff Reporter
One minute, the new Boeing 737-300 was cruising routinely in calm skies at 34,840 feet en route from Jakarta to Singapore.
The next, the jetliner was angling nose down, plummeting 19,000 feet - 3.5 miles - in less than 60 seconds.
Built to hold together flying straight ahead at four-fifths the speed of sound, the 50-ton jetliner fell faster and faster, approaching the sound barrier. Gravitational forces pinned passengers and crew in their seats and against the cabin floor and walls. Cabin fixtures began disintegrating. The tips of the horizontal tail section tore off.
Accelerating at more than 900 mph, the aircraft impaled itself nose first into the Musi River on the island of Sumatra, Indonesia. The impact was so ferocious that shattered airplane fragments were later extracted from mud 30 feet deep.
The murky, fast-flowing Musi appeared to swallow the jet whole. Bits of debris burbled to the surface, like confetti.
All 104 people on board died.
The pilot-suicide theory
Eleven months after SilkAir Flight 185 fell from the sky Dec. 19, two divergent explanations have emerged to explain why.
Each of those explanations appears viable, and each has indications in its support. They are so different, though, that only one can be true.
The first makes the chilling case that 41-year-old Capt. Tsu Way Ming, agitated by personal problems and haunted by a traumatic military experience 18 years in his past, somehow incapacitated his first officer, 23-year-old New Zealander Duncan Ward, and purposely put the 737 in its fatal supersonic dive.
Tsu has been depicted in the Wall Street Journal and in the Asian and Australian press as fitting the profile of a man bent on suicide. Many of the stories trace back to an as-yet-uncorroborated report that the pilot took out a multimillion-dollar life-insurance policy a few days before the crash, and to a rumor that the cockpit voice recorder captured strained conversation between Tsu and Ward.
Wittingly or not, Indonesian officials have helped fuel speculation about Tsu by refusing to confirm or deny his reported financial troubles and by declining to make transcripts of the voice recorder public.
"We're absolutely convinced it was pilot suicide," said Geoffrey Thomas, a reporter for the West Australian newspaper in Perth, who has reported pejorative information about Tsu leaked from sources close to the official investigation. "Everything points to it."
In recent weeks, though, attorneys Frank Fleming and David Nanz, of New York's Kreindler and Kreindler firm, have been raising an alternative explanation: that a rogue deflection of the jet's rudder, the vertical tail panel that controls the plane's left-to-right movement, flipped the SilkAir jet out of control.
Fleming and Nanz and attorneys from three other American firms representing families of 55 people killed on Flight 185 point to the striking similarities between the crash in Indonesia and rudder malfunctions suspected in the sudden fatal nose dives of Boeing 737s in Colorado Springs, Colo., in 1991; in Tucuti, Panama, in 1992; in Pittsburgh, Pa., in 1994; and in the near-crash of a 737 in Richmond, Va., in 1996.
An exhaustive, ongoing National Transportation Safety Board (NTSB)investigation of the Colorado Springs and Pittsburgh crashes has yet to pinpoint a cause for those accidents. But it has revealed design flaws in the 737 rudder system linked to instances of rudder malfunctions disrupting hundreds of flights over the past three decades.
The 737's rudder can sometimes deflect on its own, without being commanded by a pilot. Slight uncommanded rudder deflections can twist a jet briefly off course. An acute deflection, called a "rudder hardover," can flip the aircraft into a steep dive.
Boeing is in the process of retrofitting new parts in the rudder systems of some 2,800 737s worldwide. The company assures airlines and the public that the upgrades will alleviate the problems, but the work isn't expected to be complete until August 2000.
Lawsuit blames Boeing
Suzan Picariello was a 49-year-old native New Yorker working out of Singapore as an American Express executive when she boarded SilkAir Flight 185 last Dec. 19.
During the last two minutes of her life, Picariello endured "severe mental anguish and fear of impending death," according to a $25 million lawsuit filed last summer on behalf of Picariello's husband, Bryan McNelis, and their 2-year-old son.
"Our complaint specifically alleges that the SilkAir crash is a repeat of what happened in Colorado Springs and Pittsburgh, as well as other incidents of 737 departures from control reported over the years," Fleming said. "We're saying this was a product of Boeing's failure to investigate rudder malfunctions and take adequate measures to prevent it."
The plaintiff's attorneys concede their case thus far is built more on deduction than on hard evidence. However, they believe Boeing possesses telling information that will confirm their suspicions, and they've been battling longtime Boeing corporate defense attorney Keith Gerrard, of the Seattle law firm Perkins Coie, to get their hands on what they believe to be the incriminating evidence.
Fleming and Nanz have asked U.S. District Court Judge Lawrence McKenna in New York to order Boeing to produce an index of all documents generated in connection with any investigation of any suspected loss-of-control accidents or related incidents involving Boeing 737s. They've also asked for an index of all of the documents generated from long-running product-liability lawsuits the company has been defending related to the Colorado Springs and Pittsburgh crashes.
Describing the McNelis case as "totally speculative," Gerrard asked McKenna on Oct. 19 to issue an indefinite stay of the discovery process. Boeing's lawyer portrayed the airplane maker as playing only an incidental role in the SilkAir probe, saying, "all information from the accident investigation is being withheld" by the Indonesian government. And in any case, he argued, Boeing is prohibited by international rules from divulging anything it knows about the ill-fated SilkAir flight.
In response, Nanz produced a recent letter from the NTSB's general counsel, Dan Campbell, to Boeing in which Campbell clarifies that the company is prohibited from discussing the "progress and findings" of crash investigations but not "information that was in existence prior to the accident."
In fact, the NTSB's practice is to make factual material available to the public during the course of its crash investigations, leaving plaintiffs' lawyers, insurance investigators, reporters and others to make their own interpretations.
Nanz in his Oct. 26 response described Boeing as being responsible for "a major portion" of the SilkAir investigation. He noted that the chief Indonesian investigator, Dr. Oetarjo Diran, has a staff of one - a secretary - and has been "forced to rely heavily on the assistance and resources of Boeing and the NTSB."
Indonesia is so destitute, Nanz said, that when Diran brought SilkAir's flight data recorder to Washington, D.C., for testing by the NTSB last January, Singapore paid his plane fare and the NTSB paid his expenses during a three-week stay. Underscoring what he described as Boeing's "integral role" in the Indonesian investigation, Nanz accused Boeing of keeping Diran in the dark about certain findings.
"We have been informed by reliable sources in Jakarta, the location of the Indonesian Aviation Accident Investigation Commission, that accident data gathered by Boeing personnel has been and is being withheld from the Commission," Nanz told the court. "At minimum, Boeing failed to offer a complete picture . . . regarding its knowledge of the SilkAir accident's circumstances and its involvement in the Indonesian investigation."
Gerrard has until Friday to respond. Meanwhile, Boeing spokeswoman Susan Bradley said the contention that the company is largely in charge of the investigation is false.
"As far as withholding information, I know that our guys are cooperating fully with the investigation under the terms under which the investigation is being conducted," she said.
McKenna is expected to issue a ruling before the end of the year. Should he deny Boeing's request for a stay of discovery, the company could be obliged to produce some or all of the documents requested by the plaintiffs.
Those documents could release a raft of new clues about the crash. And they would be sure to rekindle a debate Boeing has faced in other crashes: whether they were the product of rudder problems, or of a pilot's actions.
Suicide in earlier crash?
Choosing between the pilot and the airplane as the culprit in a 737 crash is a dilemma familiar to U.S. aviation safety officials.
In what has evolved into the longest, most complex investigation in aviation history, the NTSB still has not reached a consensus about what happened to USAir Flight 427 near Pittsburgh on Sept. 8, 1994. The jet, also a 737-300, was flying at 6,000 feet in calm skies when it suddenly dove to the left, smashing 24 seconds later into a wooded ravine and killing all 132 aboard.
The case boils down to choosing between a scenario in which one of the veteran USAir pilots errantly steered the plane into its fatal dive - a case Boeing has gone to great lengths to make - or blaming a rudder malfunction. Last month, NTSB chairman Jim Hall told family members of Flight 427 victims that the board will vote on a probable cause at a hearing in Washington, D.C., March 23, 1999.
Meanwhile, a similar puzzle is taking shape in Indonesia. A vexing circumstance is that the cockpit voice recorder, which captures all conversations and sounds in the immediate vicinity of the pilots, stopped operating about six or seven minutes before the SilkAir jet smashed into the river.
At some point after the cockpit recorder went out, but before the dive began, the flight data recorder also stopped accumulating information. Oddly, investigators later found 13 inches of the flight data tape, which tracked the aircraft's position in the air and the position of cockpit controls, damaged by chemicals.
First Officer Ward was last heard from when he routinely asked for clearance from Jakarta air traffic control to switch communications to the Singapore controller. That conversation was about 40 seconds after the cockpit recorder stopped operating, and no stress was detectable in Ward's voice or comments. Nothing more was heard from the crew.
A blend of suspicious circumstances and rumors buttress the case for pilot suicide. A few months before the crash, Capt. Tsu botched a landing approach and subsequently deactivated the cockpit voice recorder. He told his superiors he was trying to preserve information about what had happened.
Tsu was demoted from training captain to regular captain for violating company procedures, a setback in his plans to advance to SilkAir's parent, Singapore Airlines, where he hoped to fly bigger jets for higher pay.
Those who suspect suicide point to another factor: Tsu was a former aerobatics fighter pilot in Singapore's elite Black Knights. Eighteen years earlier to the day, on Dec. 19, 1979, Tsu was flying alongside four other fighter pilots on a training run in the Philippines when he had to turn back with mechanical problems. Shortly afterward, the formation of Skyhawk fighter jets accidentally flew into the side of a mountain, killing Tsu's four comrades.
One widely reported scenario depicts Tsu as being despondent over career and financial obstacles, perhaps to the point of triggering a recurrence of a post-traumatic stress disorder known as survivor guilt.
According to reports that surfaced after the crash in Indonesia, Tsu had recently suffered huge investment losses due to the collapse of Asian securities markets and had taken out a $5 million life-insurance policy a few days before the crash.
Here's how the suicide scenario plays: En route to Singapore, Tsu makes an excuse to leave the cockpit and turns off the cockpit recorder on his way out. Upon returning, he shuts down the flight data recorder and asks Ward to check on something at the rear of the passenger cabin. Tsu then locks Ward out of the cockpit and steers the plane into its high-speed dive. Other variations of the suicide scenario have Tsu knocking Ward unconscious or shooting him just after Ward spoke with Jakarta air control.
As far as David Hiu of Singapore is concerned, any more talk of pilot suicide is a waste of time, and an affront to the victims, the pilot and the survivors.
Hiu's wife of two months, 25-year-old Candy Lai Mui Chui, was a flight attendant on Flight 185, and he has a close friend who knew the pilot.
"As far as what I know about his background, he (Tsu) was a very nice guy, a very jolly person, with a nice, happy family," Hiu said. "There are some stories that he had problems, but we all have setbacks now and then.
"It's wrong to point to his past mistakes and say it's suicide. If you want to kill yourself, there are many ways to do it and not bring 103 people with you."
In a briefing of family members and airline representatives in Singapore in August, Diran, the chief Indonesian investigator, for the first time revealed extensive details about what investigators had found.
Yet the meeting may have been most notable for Diran's reluctance to definitively address the suicide scenario.
By then, a rumor had developed that the cockpit recorder tape revealed some strained conversation between Tsu and Ward, or perhaps sounds of Tsu leaving and re-entering the cockpit. Diran might have put the rumors to rest, one way or the other, by releasing transcripts of the recording. Instead, he asked reporters to trust him that the tape held no vital clues.
Diran also declined to discuss Tsu's financial situation, debts or the life-insurance policy, saying it would take time to get relevant documents.
At the same time, Diran made observations that whet the appetite of plaintiffs' attorneys in the United States who were familiar with the 737's history of problem flights.
Diran revealed that investigators were exploring several ways the electrically powered cockpit and flight data recorders could have shut down on their own, including "localized fire, explosion, ingress of water from the galleys or a toilet located just above the electronic bay and other possible scenarios," according to his briefing notes.
He noted that a third electrical device - the plane's transponder, which responds to radar queries with location and altitude data - ceased operating as well. The last transponder response came at 19,000 feet, midway through Flight 185's nose dive.
Investigators began wondering whether the transponder failed on its own or as part of a progressive electrical problem that had knocked out the cockpit and flight data recorders a few minutes earlier. The plaintiffs' attorneys have asked the court to order Boeing to produce a detailed wiring diagram of the SilkAir jet.
Notably, the investigation of this summer's Swissair crash off Halifax, Nova Scotia, could produce fresh information about how recorders can shut down prematurely during an unfolding disaster. The MD-11, made by McDonnell-Douglas before the company was bought by Boeing, crashed Sept. 2, killing all 229 on board. Upon recovering the cockpit and flight data recorders from the ocean floor, investigators found both devices had stopped operating about six minutes before the jet hit the water.
If electrical glitches did come into play on Flight 185, could a rudder malfunction triggered by another electrical device, called the yaw damper, be a factor? So wonders Tom Ellis, spokesman for Nolan Law Group in Chicago, which represents eight SilkAir victims' families. Designed to automatically make slight rudder adjustments during flight, the yaw damper has a long-known tendency to issue rogue signals; it is one of the parts Boeing intends to change on all 737s.
In April 1994, a Continental 737-300 flying at 37,000 feet over Honduras narrowly averted a crash after a rogue yaw-damper signal deflected the rudder.
"It is plausible that you have an uncommanded rudder movement, you have the plane going into a dive, and you have the crew trying to pull it out of a dive," Ellis said. "Then at 19,000 feet, the tail rips out, the transponder goes out and all you're left with is a diving airplane that's breaking apart."
In October 1995, a British Airways 737-200 oscillated continuously for seven minutes during a test flight. Investigators found liquid from the area of the forward galley and toilet had leaked into the electronics bay, creating an electrical path between circuits in the yaw damper, which then emitted rogue signals.
As a result of that case, Boeing issued a series of voluntary service bulletins suggesting airlines install better shrouds and sealants to protect the 737 electronics bay from fluids leaking from above. But a June 20 incident in Marseilles, France, involving a 737-300 shows that the problem persists: Someone hung an overcoat on the forward galley water tap. Water overflowed onto the cabin floor and seeped into the electronics bay below, causing several electrical components - but not the yaw damper - to malfunction.
For every scenario drawn up by the pilot-suicide theorists, investigators are exploring various combinations of potential electrical and mechanical malfunctions that could have silenced Flight 185's recorders and sent it into its supersonic dive.
Diran told the family members that a reconstruction of the jet's tail section is under way and that investigators are concentrating on the rudder, horizontal stabilizer and all parts connected or related to the tail. Diran's direction of the probe is being scrutinized by the Singaporean government, owner of the airline and a major supporter of Indonesia's frail economy.
Meanwhile, the chief investigator must walk a fine line between these distinct theories, each with a body of circumstantial evidence. When - and even if - the mystery will be solved is anybody's guess.
Byron Acohido's phone message number is 206-464-2352. His e-mail address is: firstname.lastname@example.org.
Copyright (c) 1998 Seattle Times Company, All Rights Reserved.