Some more detailed SR111 Background for you |
Date: Tue, 06 Oct 1998 22:29:49 +0800
From: John Sampson <sampson@wantree.com.au>
To: Ross Coulthart <RCOULTHART@ninenet.com.au>
CC: "PEddyXX@aol.com" <PEddyXX@aol.com>,
"dbjarnas@toronto.cbc.ca" <dbjarnas@toronto.cbc.ca>,
Omega Systems Group Incorporated <omega@omegainc.com>
Rossco, Here's a compendium of articles (attached) from the Halifax News on the Swissair accident that will probably give you as good a background as you're going to get (Word6/95 format). Local rags tend to do a better in-depth coverage of these sorts of incidents. I added a comment to the first one (actually from the Swissair home-site) that may well prove to be memorable. Reading into the eyewitness accounts I'm inclined to believe that the engines were either flamed out or, more likely, were locked compressor stalling (reverse flow giving flames out the front as well as rear). This may well have been due to loss of electrics to barometric or acceleration fuel ratio control units leading to overfuelling. The revelations about the manufacturer having ordered that the flammable mylar foam sound insulation be replaced at the very earliest maintenance opportunity is a bit of an eye-opener. It would seem that any arc-wire tracking fire would have been picked up and amplified by this flammable material, leading to an indeterminable source of fire that was self-supporting (i.e. not prone to dying away if electrics were killed). Most electrical fires are not self-sustaining once the amps are shut off. This could well be the clue as to why things so quickly escalated - particularly if it is found (or revealed) that this mylar foam produces toxic smoke. On another subject. You may have read that a few days after the Swissair 111 accident that there was a near midair involving a Swissair jet that was only avoided by both aircraft being fortuitously equipped with Collision Avoidance warning systems (TCAS). You will recall the Saudia/Tajikistan midair last year where that wasn't the case. As an add-on concern to this you might have noted on the Airline Pilot forums that there is mounting concern over the slowness of ICAO regulatory authorities to endorse a growing practice on the airways of staying a mile to the right. The problem is related to the incredible accuracy of satellite navigation whereby, nowadays, if ATC does get it wrong altitude-wise (as did Delhi Centre) you are guaranteed to have a head-on. Some but not all pilots are staying a mile to the right but, equally possible I guess, a lot aren't - all for the lack of prompt action by regulatory authorities to recognise a problem and its easy fix. There are a few horror stories on the NET where individuals claim that they would have worn one in the face if they hadn't been (I guess illegally) practising this eminently sensible solution. If you're thinking of doing an airline expose sometime you may as well give them a real broad-brush broadside.. regards John Sampson |
From
www.swissair.com Clarification regarding DC bus tie sensing relay Zurich, September 11, 1998 - Media reports earlier today inaccurately reported that a DC Bus tie sensing relay had failed on another Swissair plane, prompting the airline to replace the part on all of its planes of that model. They stated that the new part was installed incorrectly on the plane that crashed near Peggy's Cove, touching off a minor fire several weeks before the crash. In actuality, on August 3 in Bangkok, on Swissair MD-11 HB-IWA, not the aircraft involved in the SR111 crash, a DC bus tie sensing relay malfunctioned during routine maintenance. The DC bus tie sensing relay was immediately replaced. As a precaution, the following day Swissair took it upon themselves to replace the DC bus tie sensing relays in the entire fleet. In Zurich, during the installation of the new DC bus tie sensing relay in the SR111 (accident) aircraft, HB-IWF, the mechanic discovered that he had incorrectly installed the part after a short circuit - not a fire - occurred. The DC bus tie sensing relay was then installed correctly and subsequent function controls confirmed that the relay functioned properly. Contact: Media Center 902-426-1070 Sampson Comment: It will be quite uncanny, that in the end, whether they realized it or not, it will be found that Swissair published the accident cause in their Press Release above. What Im proposing is that the mechanics short circuit in the accident aircraft most probably damaged the wiring downstream (and perhaps other components) and set the scene for a later inflight arc-wire tracking occurrence (as then complicated by the flammable foam sound insulation blankets that were to be urgently removed at some later date). Id like to know the date of that mechanics faulty installation. Id be betting it wasnt very long at all before the accident flight. Coincidental that in 1965, in an SP2H Neptune at Townsville I ended up on two engines (a recip and a jet) all because of a faulty bus-tie relay sensing switch. |
From Halifax Daily News
http://www.hfxnews.southam.ca/Crash/index.html
Tuesday, October 6, 1998
Data-recorder info garbled
Flight 111 investigators still struggling with black box
TORONTO (CP) - Weeks after recovering the flight-data
recorder from the wreckage of Swissair Flight 111, investigators
are still struggling to determine whether the black box has
information that will help them determine the cause of the crash
off Peggy's Cove.
Not only are the last six minutes missing from the flight and
voice recorders, but the data recorder was plagued with
anomalies before that, The Globe and Mail reported yesterday.
Investigators insist they will eventually determine the cause of
the crash that killed 229 people, but the digital record of the
critical minutes when the problems developed are so garbled, it
might offer little more than a pointer to the components or
wiring bundles where the problems began, the paper said.
"We are trying to ascertain what it is telling us," Vic Gerden,
the Transport Safety Board's lead investigator, said Sunday.
"Is it the avionics bay? Is it a (instrument) panel? Is it a wiring bundle?"
Gerden says they have not been able to narrow their focus on
the cause of the crash beyond the theory something electrical
was amiss and that probably - but not necessarily - was the
initial cause of the sequence of problems.
The investigators believe they must recover key components of
the wreckage that are 60 metres down and eight kilometres off
Peggy's Cove. And with winter fast approaching, recovering the wreckage has
become a race against time.
"We are going to require more of the airplane" brought up from the bottom, Gerden said.
So far only a few lengths of wiring from the more than 160
kilometres aboard the MD-11 have been recovered and those
show no signs of faults, the Globe reported.
"Nothing that tells us anything," said Gerden.
The flight-data recorder has 256 channels that keep track of
performance of the plane's systems as well as flight-control
inputs and the flight path.
Gerden has said divers have recovered more "heat-distressed"
bits of the cockpit, but he would not say what they are. He
would say it seems they suffered the consequences of high
temperatures, rather than to have been the likely source of the heat.
He has also said about six minutes before the crash, which was
about the time the pilots declared an emergency in their last
transmission to the air-traffic control tower, there was a
conversation on the cockpit-voice recorder.
He would not say whether they were commenting about
smoke, heat, or visibility or whether conditions were reaching
the stage where it would be difficult to fly the plane. ____________________________________________________________________
Wednesday, September 9, 1998 Airlines, gov't cost-cutting concerns former pilot By PETER McLAUGHLIN -- The Daily News Cuts by airlines and government are risking passenger safety, says a retired military and commercial pilot who investigated two airplane crashes. Gary Baker, a former flight-safety officer in both Canada and with the Royal Air Force, said yesterday he's concerned the drive for the fiscal bottom line is making air travel increasingly unsafe. "I am becoming very concerned,'' said Baker, a former base operations officer at CFB Summerside in Prince Edward Island. Over the last decade, most airlines have phased out flight engineers from the cockpits and have become over-reliant on highly automated "fly-by-wire'' systems that have rendered pilots as little more than high-altitude computer jockeys, he said. Meanwhile governments have dramatically cut air-traffic-control personnel and reduced terminal-control areas. Baker, who flew for Air Canada and piloted Nimrod jets for the military, said all these money-saving measures might have played a contributing role in the crash of Swissair Flight 111. He said, for example, the flight engineer would have been trying to determine the cause of the smoke condition and fix the problem, allowing the pilot and his first officer to properly analyse the problem and make a quick decision to land rather than wasting precious minutes circling and dumping fuel. A flight engineer is the third person in the cockpit who is responsible for checking the airplane between stops, refueling, keeping flight logs, and instrument checks. "The flight engineer is a vital member of the cockpit crew, especially in an emergency,'' said Baker, who was involved in investigating military-jet crashes of a CF-18 fighter in 1988 and an Argus in 1976. "Undoubtedly one pilot was flying the aircraft, jettisoning fuel, talking to air-traffic control, and looking at his let-down sheet for an airport he wasn't familiar with, while the other chap was trying to locate the source of the smoke.'' But aviation industry analysts say it's too soon to blame the economics of the industry for the crash and others like it. Dr. Richard Gritta, an internationally recognized expert on airline safety and competition, said there is no research that links airline efficiencies to accidents. "The jury is still out,'' he said. Gritta said a third person in the cockpit might have helped in the Swissair incident, but a flight engineer might have also ended up as "a third person being blinded'' by the smoke. said economics never played a part in the move to two-person cockpits a decade ago. safety, he said. "In many cases, automatics will identify a problem long before a crew will know anything about it,'' he said. |
Friday, September 4, 1998
MD-11s had wiring faults
By BRAD EVENSON & CHARLIE GILLIS -- Southam News
Swissair officials could not say yesterday whether the company
had corrected a problem identified two years ago in McDonnell
Douglas MD-11s - a problem that could have caused a crash
just like that of Flight 111.
The Swissair press office could not even confirm the company
had received a 1996 bulletin from the U.S. Federal Aviation
Administration outlining the potentially disastrous problem with MD-11s.
But company officials said they almost certainly would have
fixed the problem immediately after receiving such a warning.
The FAA bulletin, circulated to airlines worldwide, warned of a
wiring fault that could lead to fire and seriously impair the
pilot's ability to control the aircraft. A burnt electrical cable
found in the left aft console of a MD-11 is "likely to exist or
develop on other airplanes if the same type design," the bulletin stated.
If left uncorrected it could lead to a fire that would rob the
planes of rudder control and horizontal stability, the memo cautioned.
The warning was classified as a directive, meaning all U.S.
airlines were required to fix the problem on penalty of losing
their operating certificates.
It instructed the carriers to install a small guard over a control
cable to stop it from chafing against another wire and causing
an electrical short.
The warning could prove critical in the investigation of
Wednesday's crash: radio transmissions show the pilots of
Swissair Flight 111 were fighting for control of the plane in a
smoke-filled cockpit as they tried to make an emergency
landing in Halifax and appeared to be losing control as they
blinked off radar at 2,400 metres.
FAA directives are usually adopted by aviation administrations
around the world. While it's not mandatory for foreign carriers
to obey them, most do for fear of disaster, said FAA
spokeswoman Diane Spitaliere.
Swissair enjoys a reputation as one of the world's safest
airlines, with 19 fatality free years prior to Wednesday's crash.
Its fleet is maintained by a subsidiary which, according to one
safety expert, rebuilds its planes "like Swiss watches." __________________________________________________________________
Friday, September 4, 1998
About the MD-11
By David Rodenhiser -- The Daily News
Facts about Swissair Flight 111 and the MD-11, which crashed off Peggy's Cove:
Pilot Urs Zimmermann, 50, and co-pilot Stefan Low, 36. The
two Swiss men had flown the same jet in the last few days and
reported no irregularities.
A McDonnell Douglas MD-11, the plane was put into service
in August 1991 and was overhauled last August and September.
It had been checked before take off.
The plane had completed some 6,400 flights and 35,000 flight hours.
The MD-11 is the successor to the DC10, and is the world's
only modern wide-cabin airliner powered by three engines.
A standard configuration MD-11 (as the Swissair jet was) can carry 285 people.
It is 61.2 metres long, with a range of 12,270 kilometres, and
cruising speed of 877 km-h. Empty, the plane weighs 132,270
kilograms. Maximum take-off weight is 273,290 kg.
Built in Long Beach, Calif., there are 178 MD-11s worldwide.
The first flew in 1990. Boeing plans to stop making MD-11s in 2000.
__________________________________________________________________
Monday, October 5, 1998
Battery-powered black box `easy' - manufacturer
By Murray Brewster -- The Canadian Press
Making the so-called "black boxes" on jetliners battery powered
might be as simple as switching a couple of wires, says an
official with one of the device manufacturers.
"It's basically replacing one wire that powers the (cockpit voice
recorder) with another wire," said Greg Francois, manager of
data recorders with Allied Signals.88
"It could be as simple as modifying one wire. Personally, I
don't think it's very hard at all."
Both the cockpit voice recorder and the flight-data recorder on
Swissair Flight 111 quit working six minutes before the MD-11
crashed into the ocean off Nova Scotia on Sept. 2. All 229
people aboard were killed.
Investigators are looking into the theory a massive power
failure, the result of an electrical fire, brought down the aircraft.
The recorders are plugged into a jet's emergency power supply
that operates on an alternating current. Some systems on the
MD-11 rely on battery power in an emergency.
Some have suggested black boxes, which keep track of the
plane's operations, be battery powered to give investigators
more information.
"We have six minutes here that we'll never know thanks to the
fact that we've never independently powered these devices,"
said John Nance, an aviation analyst in Tacoma, Wash., with
35 years' experience as a commercial pilot.
"It's time to do it."
Francois said the rewiring process in most cases would not be a
complicated or expensive procedure, although it would depend
on the age of the aircraft and the recorders. But he questions
whether it's necessary to have both devices backed up with batteries.
Cockpit conversations would be of the most use to investigators, Francois said.
"The (flight-data recorder) is a highly distributed system on
modern airplanes," he said.
"The recorder itself is really just a dumb box that gets a digital
data stream." It is useful only as long as there is data to input,
said Francois. In the case of a massive power failure, the device
would have nothing to record anyway.
___________________________________________________________________
Saturday, September 5, 1998
Toxic fumes possible cause of crash
WASHINGTON (CP-staff) - A crew disoriented by toxic
fumes fed by a fire caused by faulty wiring might be the cause
of the Swissair Flight 111 crash, a former senior investigator for
the U.S. National Transportation Safety Board said yesterday.
The lack of fire on the water, relatively small fuel slick and
witness accounts of groaning and sputtering engines before the
crash suggests the MD-11 might have run out of fuel after a
disoriented crew failed to notice how little remained in the jet's
tanks, said Vernon Grose.
"Wiring will be the No. 1 suspect," said Grose, who
investigated at least a dozen jetliner crashes as head of the
NTSB's "Go-Team" of major accidents. A 1996 U.S. Federal
Aviation Authority bulletin warned of a wiring fault that could
lead to fire and seriously impair the pilot's ability to control the aircraft.
But in Halifax yesterday, Swissair spokesman Hans Klaus said
guards had been installed in the company's fleet of 18 MD-11s.
"There is an upgrade that was made," Klaus said. "It was done
since a long time on every plane of the Swissair fleet."
John Nance, an aviation analyst and author in Tacoma, Wash.,
where Boeing manufactures most of its aircraft, said it would
be fair to extrapolate based on what's known now that the crew
were incapacitated before the plane hit the water.
"Pilots don't give up," Nance said. "Either they were
incapacitated by some toxicological agent or they could no
longer control the aircraft."
Grose said: "It will be very important to listen to the tapes of
the voice cockpit recorder to see if the pilots' speech was slurred."
Those tapes were still beneath the ocean surface on the as-yet
unlocated cockpit voice recorder. But Vic Gerden, the lead
Canadian investigator in Halifax, said a reading of the transcript
of the flight crew's conversations with air traffic controllers
suggested they were dealing with the situation in a professional manner.
The transcript suggested the crew realized they were in an
emergency but were reacting calmly, the Canadian investigator
said yesterday afternoon. But Nance said there was clearly
some sudden unforseen deterioration in the condition of the
pilots or aircraft.
"If this was an uncontrollable situation, this crew would have
headed directly for the airport. There would be no turning away
from the airport to dump fuel."
Nance said the Swissair crew turned the MD-11 southwest and
stabilized their flight pattern while dumping fuel - a standard
procedure to reduce risk of fire before making an emergency landing.
"Suddenly there is a course reversal of 180 degrees straight
toward Halifax airport," Nance said. "Things began to
deteriorate and deteriorate very fast, more than likely an
uncontrolled descent into the water."
"There may have been a fire below decks that masqueraded as
being under control, that was quickly out of control."
Judging from the wreckage and remains recovered so far, there
was little sign of a fuel-fed fire or explosion on board, the U.S.
experts said.
There was no fire either on the surface of the ocean near
Peggy's Cove, where the Swissair plane went down. In
contrast, there was a ring of flames around the crash site off
Long Island, N.Y., when TWA Flight 800 crashed two years ago.
The absence of these factors suggests an electrical fire that
might have had its flames in a concealed place and generated
smoke that confused the crew to the point where they might
have dumped too much fuel, Grose said. The Swissair pilot told
air traffic controllers minutes before the crash Wednesday night
smoke was filling the cockpit.
"There might have been so much smoke in the cockpit that the
pilot might have been disabled by toxic fumes and couldn't tell
how little fuel he had in the aircraft," said Grose.
"No fire on the water, along with the gasping, sputtering engines
tells me he had nothing in the tanks."
Witnesses who heard the jet before it plummeted into the ocean
said the three engines were not making the usual high-pitched
screech of jet engines when the aircraft passed over the Nova Scotia shore.
"It sounded terrible," said Edie Boyle. "It was just droning."
"The motors were going, but it was the worst-sounding deep
groan that I've ever heard," said another witness, Claudia
Zinck-Gilroy.
________________________________________________________________________
the Swissair incident, but a flight engineer might have also
ended up as "a third person being blinded'' by the smoke.
Robert Vandel, director of technology projects with the
Virginia-based Flight Safety Foundation, said economics never
played a part in the move to two-person cockpits a decade ago.
Automation drove the industry to eliminate the third crewmember.
The industry believes automation is superior to having human
beings solely responsible for safety, he said. "In many cases,
automatics will identify a problem long before a crew will know
anything about it,'' he said.
____________________________________________________________________
Friday, September 25, 1998
Wiring safety questioned since 1973
Regulators, airlines, and aircraft manufacturers have long had
misgivings about a controversial wiring insulation used aboard
Swissair's doomed MD-11 jet that crashed off Peggy's Cove on
Sept. 2, documents show.
Letters and internal reports obtained by The Canadian Press
suggest the safety of aromatic polyimide insulation has been
repeatedly questioned by the industry since at least 1973, when
it failed aboard an L-1011 aircraft.
The insulation, known by its DuPont trade name Kapton, was
banned from many U.S. military aircraft more than a decade
ago, but is still used aboard commercial airliners, including
many MD-11s.
"Because of Kapton's notch sensitivity and other minus factors
such as springiness, delamination, difficulty in stripping, and
cost, we will strongly object to any proposed use of this wire on
future TWA aircraft," TWA's director of electronics
engineering wrote the Boeing Co. on June 30, 1977.
The U.S. navy first took measures to limit the use of aromatic
polyimide tape in its aircraft in the 1980s after it was found to
break down under the extremes of heat and humidity found at sea.
Wire-and-cable experts likened that to a canary in a coal mine.
A 1982 U.S. air force memo said Kapton's "top coat is
susceptible to chafing ... and its insulating material can absorb water."
FAA tests "demonstrated that the ability of an aircraft wire to
resist wet arc-tracking and possible flash-over is highly
dependent on the composition of the wire insulation."
McDonnell-Douglas, since taken over by Boeing, began using a
combination of Kapton and Teflon known as TKT. But the
polymer insulation remained in 727s and older MD-11s. - CP
_____________________________________________________________________
The Daily News
Thursday, October 1, 1998
No one at controls - expert
Flight 111 crew died, left cockpit before crash
By Stephen Thorne -- The Canadian Press
EASTERN PASSAGE - A Swiss pilot and his co-pilot
probably abandoned the cockpit, lost consciousness, or died
before their MD-11 passenger jet plummeted into the Atlantic
Ocean, says an aviation expert.
Evidence collected from the site where Swissair Flight 111 went
down suggests there was no one at the controls of the
wide-bodied jet shortly before it crashed Sept. 2, said Vernon
Grose, a one-time presidential appointee who says he's spoken
to people close to the probe.
"It may be that the crew expired before they hit," Grose said
yesterday from Arlington, Va. "They may have abandoned the
cockpit just due to the fire there and set it up as best they could."
Deepsea divers coming off a gruelling month salvaging the
downed jet described melted electrical equipment and other
evidence the plane's cockpit was an "undesirable place to be" in
the minutes before it crashed.
"Some of that circuitry has gone through a lot of testing to
make sure it will not do this - it will not get hot, it will not melt
down - and it was really stressed by heat," said Leading
Seaman Gavin Wort, a navy diver.
"Circuits had been melted. Wires were melted. Obviously, if
that's anywhere near a human being up in the air, that's not
going to be a desirable place to be."
Wort and fellow divers have spent the last month off Peggy's
Cove recovering remains of the plane's 229 passengers and
crew along with key evidence. The pilots' bodies have not been
identified, said a spokeswoman.
Investigators believe the plane succumbed to massive electrical
failures. Swiss pilot Urs Zimmermann reported cockpit smoke
about 18 minutes before the jet disappeared from airport
radars. Cockpit voice recordings indicate the smoke first
appeared three minutes before they radioed the problem.
The plane's black boxes stopped working six minutes before the crash.
Canadian authorities said they have not recovered enough
material to back Grose's theory and cautioned some pieces that
appear to be burned are not.
"We've got some parts with definite heat stress on them, and
they come from the cockpit area - there's no doubt about that,"
said Jim Harris, a spokesman for the Transportation Safety
Board of Canada.
"There's not enough of those pieces to develop any sort of hypothesis."
But Grose, who served on the U.S. National Transportation
Safety Board and was a consultant to several inquiries, said the
cockpit crew might not have donned masks quickly enough to
avoid toxic smoke.
"The smoke may have gotten to them physiologically," said
Grose. "They could have burned to death or they could have
just passed out."
Some evidence indicates melted materials dripped on to cockpit seats.
"Rather than just burn to death, they might have set it up as
best they could do with an autopilot and got out of there," said Grose.
"It's a frightening thing, to say the least."
Recovery efforts have continued since the crash. Heavier lift
equipment is expected to take over the operation soon.
Divers described a surreal underwater world of jagged, twisted
metal stacked five metres high and dotted with human remains.
Their lifelines, which run along the ocean bottom and up to the
surface 19 storeys above were constantly getting snagged in
wreckage, threatening their every movement.
"It's a scramble down there," said Leading Seaman Scott
Murphy, 30, of Witless Bay, Nfld. "You get as much as you
can in as short a period of time as you can."
The plane is in "millions and millions" of pieces, some as small
as a pie plate and most concentrated in a 70-by-30-metre area.
Little was recognizable, nor was it in any sensible order as
divers worked madly to make the most of their maximum 28
minutes at the bottom. Each dive required a slow ascent and
nearly three hours in a decompression chamber.
Investigators and manufacturer's representatives watched every
dive, directing divers to sites of specific interest.
"They seemed to have a keen eye for the burnt wires and
circuit boards, anything that could give them some sort of idea
as to what happened," said Wort.
Diving operations in the search zone were scaled back
yesterday in preparation of heavy-lift operations. U.S.S.
Grapple and HMCS Halifax returned to port this morning.
HMCS Halifax, which handled duties as on-scene commander,
has turned those duties over to HMCS Anticosti. Anticosti
continues to conduct video sweeps of the area using
remote-control submersibles.
Canadian divers are on standby at the fleet diving unit near
Shearwater. Investigators are considering using a heavy-lifting
barge, the Saipem 7000, to pick debris off the ocean floor.
__________________________________________________________________
Wednesday, September 23, 1998
`
Magic bullets' soughtEngine controllers might have kept working after black boxes cut out
By RICHARD DOOLEY -- The Daily News
Transportation Safety Board investigators are hoping navy
divers will surface with any number of "magic bullets" that
could solve the riddle of Swissair Flight 111.
The Boeing MD-11 crashed into the ocean off Peggy's Cove on
Sept. 2, killing all 229 people on board. Canadian and U.S.
navy divers have been involved in a massive recovery operation
off the coast to retrieve victim remains and key aircraft components.
The plane crashed shortly after the flight crew reported smelling
smoke in the cockpit. The pilot had declared an emergency and
was trying to make an emergency landing at Halifax
International Airport when the plane went down.
Investigators are looking for computer memory chips in the
plane's three jet engines. The engine controllers, as they are
called, could tell investigators what happened during the final
six minutes the flight-data recorder and cockpit-voice recorder
did not function.
"That could be very, very useful," said Transportation Safety
Board spokesman Dana Doiron.
Doiron explained, because the engine controllers are powered
directly from the engines themselves, they might still contain
data up to the point of impact. The controllers normally supply
data to service technicians who plug them into a service computer.
Investigators speculate increasing electrical problems crippled
the aircraft as it was flying from New York to Geneva.
Components in the avionic bay of the aircraft, a large
compartment located directly under the cockpit that is the
plane's main electrical switchboard, would also be valuable to
the investigation, said Doiron.
"That is what the teams are looking for now," he said.
Investigators refer to these components as "targets of priority."
Divers have been asked to bring up any parts of the aircraft that
appear burned and to look for "targets of opportunity." Those
might include wiring components and items that might help identify victims.
Remotely operated submersibles are being lowered on the
debris field from by Canadian Coast Guard and navy ships to
videotape debris, but also to make the recovery operation a
little safer for divers working from the USS Grapple and the
Canadian diving tenders Granby and Sechelt.
The submersibles are being used during the night to move
debris around and remove underwater hazards. Divers have
snagged umbilical lines and ripped suits and gloves on the razor-sharp debris.
The submersibles have also exposed human remains under the debris. More than
900 kilograms of remains were recovered over the last few days.
Navy salvage experts are looking for ways of bringing up more
pieces of the plane all at once.
"We have to be careful when we do that because if lose them,
we have to go back down and find them again," said Canadian
Forces spokesman Capt. Andre Berdais.
Investigators are also keeping an eye on the weather.
Underwater currents and tides keep the debris field in constant motion.
A storm could magnify the effect and spread the debris outside
the 70-metre by 30-metre main wreckage site.
"There are a couple of tropical storms we are keeping an eye on," said Doiron.
____________________________________________________________
Wednesday, September 23, 1998
Third recorder could shed light
Investigators probing the crash of Swissair Flight 111 are
holding out hope a third black box might carry information lost
when two others fell silent in the flight's final six minutes.
The quick-access recorder, an optional device for maintenance
purposes, might have continued operating after the flight-data
and cockpit-voice recorders quit as the MD-11 descended
below 10,000 feet on Sept. 2, officials said.
The device, known as the QAR, has yet to be found. The box
doesn't monitor as many systems as the critical flight-data
recorder. It also doesn't have a locator beacon and it isn't crash-proof.
But investigators say it might still contain valuable data that
could help them explain the deaths of 229 passengers and crew
about 18 minutes after pilot Urs Zimmermann reported smoke
in the cockpit.
"It is a possibility," said Dana Doiron of the Transportation
Safety Board of Canada. "Like all other pieces, it's the luck of
the game how it survived the crash.
"But also, the individual components inside - the memory and
the tape - wouldn't necessarily be destroyed. It's a matter of
taking the magnetic tape and cleaning it and trying to retrieve
data from it."
Investigators suspect electrical problems led to the progressive
failure of systems on the wide-body aircraft before it finally
crashed near Peggy's Cove.
Other monitoring systems could also answer questions. Among
them are three digital engine controls, or small computers, and
avionics circuit boards with memory chips that can retain
information after the power quits.
Investigators also want to focus on cockpit devices and any
systems the flight-data recorder suggested had problems.
There is more than 260 kilometres of electrical wire aboard an
MD-11. CP
_____________________________________________________________________
Friday, September 18, 1998
Mangled jet slows experts
By RICHARD DOOLEY -- The Daily News
Wreckage from Swissair Flight 111 is so mangled and
fragmented even aviation experts are having trouble identifying
pieces of the jet.
"We are slowly identifying pieces of the wreckage, but even the
manufacturers representatives are having trouble identifying
individual pieces of the plane," said Vic Gerden, chief
investigator for the Transportation Safety Board.
The Swissair jet, a three-engined, wide-bodied Boeing MD-11,
crashed off the coast of Nova Scotia near Peggy's Cove Sept.
2, killing all 229 people on board. The plane was attempting to
make an emergency landing at Halifax International Airport
after the pilot and co-pilot detected smoke in the cockpit.
Investigators are using remoteoperated, submersible camera
platforms to videotape pieces of wreckage for identification.
But the plane is so badly destroyed in many cases searchers
must zoom in on the serial numbers of parts to try to identify them.
"A typical piece of wreckage is about a metre or less," said
Gerden, showing a piece of wreckage identified as part of the
housing around the main landing gear of the airplane. The piece
is no larger than a child's car seat.
The search is concentrated on a debris field narrowed to a
70-metre-by-30-metre section of seabed.
Underwater video footage of the debris field shows rubble piled
upon rubble in a tangled mass of wreckage and human remains
in about 60 metres of water.
Sonar targets interpreted as larger intact pieces of fuselage have
proven to be piles of debris spread along the seafloor. Gerden
said that alone is giving investigators some leads.
"The size of the pieces indicates the violence of the initial
impact," he said. Searchers have made underwater camera
contact and sonar contact with what investigators hope might
be one of the jet's engines.
Information from the engine's on-board computer may yield
some clues to why the jet took its fatal plunge into the sea.
Investigators also want to get a look at the plane's avionics,or
electronic controls, to prove or disprove the theory electrical
faults disabled the jet.
"The recovery of the avionics is potentially important," said
Gerden. Computer chips in the avionics may give some clues to
flight information and how the plane was handling before it crashed.
But finding specific pieces might be a slow process. Divers
move carefully through the dark underwater carnage. Suits are
easily ripped on the jagged pieces of metal.
Divers plan their dives by viewing the area using the
underwater video cameras.
Meanwhile, analysis of the cockpit voice recorder recovered
last week shows the crew discussed a burning smell about 31/2
minutes before they made a trouble call to air-traffic control in
Moncton reporting smoke in the cockpit. The pilot and co-pilot
had begun trouble-shooting to determine the source of the smell
when they made their trouble call, and a 11/2 minutes later they
donned oxygen masks as they followed a normal checklist to
deal with smoke of unknown origin.
_____________________________________________________________
Debris offering clues to fate of Flight 111
By RICHARD DOOLEY -- The Daily News
The debris spread across the floor of Shearwater's Hangar B is telling a story.
The mangled metal, plastic, and wiring set inside a grid pattern
on the floor representing a passenger jet is all that remains of
Swissair Flight 111.
The New York-to-Geneva-bound flight crashed off Peggy's
Cove on Sept. 2, killing all 229 passengers and crew on board.
The typical piece is no more than a metre in diameter. There
are some larger pieces of debris. An aft section of the fuselage
is about 10 metres long and the left, main landing gear are the
largest pieces pulled off the ocean bottom about 10 kilometres
southwest of Peggy's Cove.
"This is a very time-consuming process," said Jim Foot, a
Transportation Safety Board investigator examining wreckage.
"Even identifying individual pieces is difficult unless you get a
large piece like the landing gear."
Investigators pore over wreckage looking for bits of serial
numbers or anything that can tell them where it came from on the aircraft.
Boeing representatives are helping the Transportation Safety
Board identify the debris.
"They've been providing us with invaluable assistance," said Foot.
The investigators have been able to determine a few things
from the wreckage they've seen.
The plane's landing gear was retracted at the time of the crash.
Besides some heat-damaged wreckage, positively identified as
from the cockpit area, other small bits of wreckage appear to
have sustained heat damage. Investigators aren't sure what area
of the plane the debris is from. There have been significant
amounts of cockpit debris or sections of the aircraft's avionics,
or electrical, system.
Analysis of the wreckage and the underwater debris field should
tell investigators the angle at which the plane struck the water.
"The main debris is in an area about 70 metres across," said
Foot. "Consider we are talking about a (60-metre) long aircraft
with a (51-metre) wing span contained in a small area."
Comparisons are inevitably drawn with the explosion of TWA
Flight 800 over Long Island, N.Y. That air disaster killed 230
people and scattered debris over a wide area of ocean.
Investigators there partially reconstructed the fuselage of the plane.
No such reconstruction is being planned for Swissair Flight 111.
Foot said 3-D reconstruction is expensive and not always
necessary to find the cause.
"This is not like the TWA accident where you had an in-flight
separation and investigators had to do a 3-D reconstruction to
find the where, the why, and what happened," said Foot.
Swissair Flight 111 investigators have several ideas already of
what happened to the aircraft as it was approaching Halifax
International Airport for an emergency landing after the pilots
reported smelling smoke in the cockpit.
The plane was crippled by electrical problems and investigators
want a look at electronic components or any components
containing computer memory chips.
An engine controller, from one of the three jet engines, was
sent to the jet engine manufacturer Pratt and Whitney. The
controller might contain electronic data that will give
investigators a clue to the cause of the crash.
Diving operations continue in the search zone.
_____________________________________________________________
Thursday, September 17, 1998
Flight 111 `shattered'
Swissair wreckage appears to be in piles of rubble on ocean floor
By RICHARD DOOLEY -- The Daily News
Swissair Flight 111 shattered like glass hitting cement when it
crashed into the ocean off Peggy's Cove, contradicting earlier
reports of several large sections.
"The divers are telling me the wreckage looks like a Coke bottle
dropped on a cement floor," said Canadian Forces spokesman
Capt. Andre Berdais. "There is nothing recognizable as an aircraft there."
Cmdr. Greg Aikins of HMCS Halifax, a naval frigate collecting
debris concurred.
"The aircraft is literally shattered on the bottom," Aikins said.
"Thus far there are no big pieces except for big things like landing gear."
The federal Transportation Safety Board had said the plane
was in five large sections on the rocky ocean floor of St.
Margaret's Bay. One of the sections detected by sonar was
thought to be a piece of fuselage containing bodies.
The largest piece lifted yesterday aboard USS Grapple, a U.S.
navy salvage ship, was about the size of a pool table.
Asked about the five pieces of fuselage originally thought to
exist, Aikins said: "That is clearly not the case."
Sidescan sonar sweeps of the debris field had picked up five
large sections of what searchers hoped were fuselage. Sweeps
with higher resolution sonar and remotely operated underwater
cameras now show the large sections might be just piles of rubble.
"The large pieces may be just an illusion," said Transportation
Safety Board spokesman Jim Harris.
Navy and police divers are picking up the tempo in collecting
human remains and debris from the search zone about 10
kilometres southwest of Peggy's Cove.
"Our main priority remains the retrieval of human remains,"
said Berdais. A massive recovery operation has been in effect
since the fatal jet crash Sept. 2.
Berdais said divers have moving faster because a lot of human
remains are entangled in the piles of debris.
"If we find something that we are specifically asked to bring up,
we bring it up as we find it," said Berdais.
Investigators are especially interested in recovering the wiring
and cockpit area of the jet, Transportation Safety Board
spokesman Dana Doiron said.
Searchers are concentrating on completing detailed mapping of
the ocean floor and using laser-equipped sonar to get an
accurate picture of the debris fields.
"We are looking at probable areas where there might be
wreckage and trying to prove or disprove it is there," said
Harris. "We are still trying to get a handle on what is down there."
Both the flight-data recorder and the cockpit-voice recorder
stopped working six minutes before the plane crashed. The
flight-data recorder did pick up a series of progressive faults in
the plane's electrical systems.
Good weather made diving operations easier yesterday.
___________________________________________________________
Beacon trouble caused confusion
By Dean Beeby -- The Canadian Press
The Swissair disaster is the third airline accident in Atlantic
Canada in the last year in which a satellite-based rescue system
could not be used to direct search crews to the precise location of a crash.
The Boeing MD-11 airliner that crashed Sept. 2 near Peggy's
Cove, killing all 229 aboard, carried a rescue beacon in its tail
section designed to emit an emergency signal automatically in a crash.
But the device, known as an emergency locator transmitter or
ELT, was not intended to work under water, said Emil Srehner,
a Swissair maintenance official in Zurich.
"It was really designed for an accident on ground," Srehner said
in an interview. "It's not designed for water."
An international satellite system picked up the beacon in the
general area of Peggy's Cove, but the battery-driven signal was
too weak for rescue aircraft to home in precisely on the transmissions.
"The ELT itself was somewhat damaged or partially
submerged," said Maj. Michel Brisebois, head of the rescue
co-ordination centre in Halifax. "Our airplanes weren't capable
of homing in on it."
Initial search a large area
As a result, the initial search area encompassed a
36-kilometre-wide swath of land and sea around Flight 111's
last-known radar position off Peggy's Cove, when the aircraft
was still about 300 metres off the ground, Brisebois said.
Compounding the problem was the accidental triggering of
another rescue beacon on a pleasure craft near Digby that was
being put away for the winter.
"It confused the whole issue because we thought that that signal
was part of the (Swissair) ELT and within a few hours we
found out it was a different one," Brisebois said.
15 minutes to confirm crash
Last Dec. 16, rescue workers spent almost 15 minutes
confirming an Air Canada regional jet had crashed in thick fog
at Fredericton airport. None of the 42 people aboard was killed,
but several passengers suffered injuries when the aircraft
plowed into trees.
Federal regulations dating from the 1970s did not require the jet
to carry a rescue beacon that might have helped confirm the
crash and identify its precise location. Transport Canada
officials have since begun a review of regulations.
And on May 18, a Pilatus PC-12 aircraft with 10 people aboard
crashed-landed in a bog near Clarenville, Nfld. No one died but
several suffered severe injuries.
The aircraft did not carry a beacon to direct search-and-rescue
crews because it had been removed for servicing, as allowed by
federal regulations. Transport Canada officials are also
reviewing this regulation.
The Swissair device, standard in the industry, is based on older
technology Canadian search-and-rescue officials have long
lobbied against. They are pressing for a new beacon, used in
the marine sector, that provides a more precise location, down
to within 100 metres.
The new beacons cost about 10 times the $200-to-$300 price
tag for the older technology.
_____________________________________________________________
Wednesday, September 9, 1998
Tripping breaker `sealed fate' - experts
By Stephen Thorne -- The Canadian Press
The pilot of doomed Swissair Flight 111 may have sealed his
own fate and that of 228 others aboard by resetting a circuit
breaker as his troubled jet descended below 10,000 feet, say
aviation experts.
Pilot Urs Zimmermann might only have been following
procedure as he brought his Boeing MD-11 down to an altitude
that allowed him to open a window to clear cockpit smoke, say
wire-and-cable experts. But what he likely didn't know might
have killed him.
The wiring aboard Zimmermann's plane was laden with
aromatic polyimide tape insulation, or Kapton, a widely used
aviation product the U.S. military banned 11 years ago because
it's prone to breakdown and can promote electrical arcing.
Edward Block said in an interview from Washington, D.C. that
emergency checklists often recommend testing circuits by
resetting circuit breakers once enough cockpit smoke has cleared.
Detailed air-traffic-control transcripts released yesterday suggest
Zimmermann and co-pilot Stephan Loew were following a
checklist as they tried to overcome the difficulties they faced.
Block was the U.S. Defence Department's wire-and-cable
expert when Kapton was banned from American military
aircraft in 1987. He is now investigating last year's TWA 800
crash off Long Island, N.Y.
He said many airline pilots are unaware of problems specific to
Kapton that could spell disaster if flight crews follow normal
procedure once a circuit breaker is tripped.
"Your tendency would be to reset that circuit breaker to see
what happens and, in so doing, you've sealed your fate. It's just
the beginning of the end." Investigators have said evidence in
the crash of Flight 111 off Peggy's Cove suggests an electrical
failure below 10,000 feet.
Early information from the flight-data recorder released
yesterday suggests systems aboard the MD-11 did not all fail at
once, said Vic Gerden, chief investigator for the Transportation
Safety Board of Canada.
Block said a pilot would typically isolate the source of the
smoke then, below 10,000 feet, help vent the air by opening the
cockpit window.
"Then you reset the circuit-breaker," said Block. "In so doing,
you've now sent a charge of electricity to a charred wire
insulation that is now going to actually ignite into what is called
a flash-over effect."
A flash-over, or arcing, refers to electricity escaping from a
wire like a bolt of lightning.
Patrick Price, a retired wiring technician who built Boeing's
arc-tracking laboratory in Seattle, called aromatic polyimide
tape insulation, or Kapton, "the most explosive wire that they
can put on an airplane right now.
"Every time you get into an airplane that's flying with Kapton
wiring, you are flying with a potential incendiary bomb that's
ready to go off at any time if the conditions are just right."
Wiring problems aboard MD-11s have been the subject of
several U.S. Federal Aviation Administration directives warning
of potentially hazardous configurations in the cockpit and in a
rear console for flight attendants.
Swissair president Jeffrey Katz has said his company complied
with all FAA directives. However, the directives did not say the
Kapton insulation should be changed.
______________________________________________________________
Thursday, September 10, 1998
MD-11 didn't fare well in safety study
By Stephen Thorne -- The Canadian Press
Boeing MD-11 aircraft, like the one that crashed off Peggy's
Cove last week killing all 229 aboard, are less reliable than their
low accident rate suggests, says a top consultant.
An analysis to be published in the next issue of Aviation
Quantitative Reports on Safety, a research newsletter, assesses
the wide-bodied jets that have had just two fatal crashes in
eight years since they have been built.
"Accidents are an insufficient criteria of safety," says Dr. Alex
Richman, a Halifax epidemiologist and former professor at
Dalhousie University who turned his expertise to airline safety
after his son was killed in a 1991 Los Angeles runway collision.
Richman's team assessed critical problems in 43 MD-11s and
300 757s that filed service difficulty reports in the United States
between 1991 and 1995.
During the five-year period, there were 167 safety-related
reports and recommendations filed on fewer than 50
U.S.-based MD-11s. There were only 144 filed on behalf of
more than 300 U.S.-based 757s.
Almost a quarter of the MD-11s - 23.3 per cent - took the
precautionary procedure of dumping fuel at least once,
compared with none of the 757s.
More than 37 per cent of the MD-11s shut down engines,
compared with 20 per cent of 757s. And more than 72 per cent
of MD-11s made unscheduled landings, compared with 51.3
per cent of 757s.
"There is little in these data to support the idea that the MD-11
is exceptionally safe," said Richman, whose methods and
results are widely accepted throughout the industry. "Accidents
are the tip of the iceberg."
Richman compared the wide-bodied MD-11s with the
narrow-bodied 757s because there are no other wide-bodied,
tri-engined jets to compare with the MD-11. Also, the two
aircraft are of similar vintage.
Swissair Flight 111 crashed into the Atlantic off Peggy's Cove
on Sept. 2, the apparent result of an electrical fire. Swissair has
said the plane was well-maintained.
Richman said the number of safety reports on MD-11s is
particularly disturbing given the departures involved - 96,500
for the MD-11s compared with almost 2.2 million for the 757s,
or almost 23 times as many 757 takeoffs.
He also cited flying hours - 594,400 MD-11 hours compared
with 5.2 million for the 757. He calls the results troublesome:
Vibration was reported in 27.9 per cent of MD-11s and 7.7 per cent of 757s.
Warning lights came on at least once in 74.4 per cent of
MD-11s and only half of the 757s.
There were hydraulic malfunctions in 39.5 per cent of
MD-11s and only 14 per cent of 757s.
_____________________________________________________________
Tuesday, September 8, 1998
Jet wiring insulated with volatile tape
U.S. navy banned its use after poor performance
By Stephen Thorne -- The Canadian Press
Much of the electrical wiring aboard a plane that crashed into
the Atlantic Ocean was insulated with a highly volatile tape that
has been banned from use in U.S. navy planes, the
manufacturer confirmed yesterday.
All the general-purpose wiring aboard Swissair Flight 111 was
insulated with aromatic polyimide tape, also known by the trade
name Kapton, said Susan Bradley, a spokeswoman for the
Boeing Co. in Seattle, Wash.
"The Swissair airplane was exclusively Kapton for
general-purpose wiring," Bradley told The Canadian Press.
The cockpit smoke reported by pilot Urs Zimmermann before
he crashed was likely the result of an electrical fire that could
have shut down the plane's fuel supply, said Vernon Grose, a
Virginia consultant.
Grose, a wiring expert and former crash investigator, said
Zimmermann and co-pilot Stephan Loew might also have
blacked out before their transatlantic flight ended Wednesday in
waters off Peggy's Cove, killing all 229 aboard.
"There was a fire or arcing somewhere producing that smoke,"
Grose said in an interview. "The most likely culprit is electrical."
Aromatic polyimide tape insulation often becomes brittle, he said.
Hop, skip, jump down wire
"Under vibration, or shock, sometimes water or contamination -
spilled coffee or anything else - it will break over and when it
arcs, it arcs at about 5,000 degrees Kelvin, which would
vaporize anything in the area.
"Furthermore, the arc tracks," added Grose, a wiring specialist
who investigated the ValuJet Flight 592 crash in Florida in 1996.
"It will go hopping, skipping, jumping down a wire bundle.
When that happens, you can have all kinds of anomalies electrically."
Indeed, Flight 111's position beacon cut out below 10,000 feet,
leaving air-traffic controllers with only a blip to follow on their
radars and no altitude data. Witnesses reported seeing the plane
pass low overhead with her exterior lights out and cabin lights lit
up "like a hotel."
Grose said those same anomalies could also have affected
displays or fuel pumps as Flight 111 dumped fuel over St.
Margaret's Bay to lighten its landing load. Residents reported
sputtering or silence as it passed over.
"All that kind of audio testimony makes me believe he was in
fuel starvation," said Grose, noting there was no fire after the
jet hit the water even though its three engines were hot.
"If there was electrical failure of the pumps they could go right
on running, or if some of the guardian circuitry (designed to
prevent dumping the tanks empty) was gone, they could just
leave the aircraft dry."
He said Zimmermann and Loew could also have been blinded
by dense smoke and unable to read the instrument panel at all.
Wiring problems aboard MD-11s were the subject of two U.S.
Federal Aviation Administration directives, in 1996 and 1997.
They warned of potentially hazardous wiring in the cockpit and
in a rear console for flight attendants.
Swissair president Jeffrey Katz has said the company complied
with all directives. But the directives dealt with configurations, not materials.
Bradley said it was found in 1995 another combination of
insulation, Teflon and Kapton, was cheaper, lighter and met
safety standards.
Could break down in four years
"So they started transitioning," she said. "They went through
their Kapton stores and started introducing this TKT wiring so
some MD-11s have both kinds on board."
But not the particular aircraft piloted by Zimmermann, she said.
The U.S. navy banned aromatic polyimide tape insulation, or
Kapton, from its aircraft because of poor performance, Air
Safety Week, an industry newsletter, reported in yesterday's edition.
"Although the accident aircraft was only seven years old, this
type of wiring was observed to break down, creating conditions
for electrical arcing, in four years of service on some navy
aircraft," said the newsletter.
The fact aromatic polyimide tape insulation and older Poly-X
insulation remain aboard commercial aircraft highlights a
problem with the American regulator, said Grose.
"The FAA has not developed and maintained a competence on
wiring," he said. "They've acted as though once it's wired, it's
going to stay there.
"But it isn't that way and it does have a lot problems over time."
Grose, who recently completed a study of airport emergency
response for Transport Canada, also painted a disturbing
picture of Flight 111's last moments in the cockpit.
He said oxygen masks could have leaked and would not
necessarily have prevented Zimmermann and Loew from
blacking out, noting the flight data and cockpit voice recorders
should go a long way toward telling the story.
With only a partial air-traffic control tape to go on, the cockpit
voice recorder, particularly, should help investigators determine
whether there was "any physiological impact of smoke on the crew."
____________________________________________________________
Saturday, September 12, 1998
Second black box recovered
By RACHEL BOOMER with CP -- The Daily News
Hopes of finding exactly what caused the crash of Swissair
Flight 111 grew stronger yesterday when navy divers retrieved
the cockpit voice recorder.
But Transportation Safety Board spokesman Jim Harris warns
it will probably take at least a day for the recorder's information
to be analysed - if it contains information.
"If the recorder works, it could be a very good piece of data for
us. If it doesn't work, we're back to where we were before we
found it," said Harris.
"It'll enable us to tell what happened, definitely, as long as it works."
Using side-scan sonar, the investigation team located the
cockpit voice recorder - one of two twelve-by-twelve
centimetre, so-called "black boxes" - Monday. Poor weather
conditions kept divers from retrieving it until yesterday at 6
p.m., when it was brought up in fresh water from the ocean
floor, a depth of about 60 metres.
Its companion, the flight data recorder, was discovered to have
stopped working as the plane descended past 10,000 feet, and
no data was available from the flight's last six minutes. Experts
at the transportation safety board's Ottawa engineering lab have
begun to flush out the salt water, dry the recorder, and prepare
it for playback.
The cockpit voice recorder tapes all sounds in the cockpit,
including conversations, engine noises, and any warning sounds
from cockpit instruments. When it's working properly, it
recycles its tape every 30 minutes. A time code is stamped on
the tape each time someone speaks, making it easy for
investigators to tell precisely what data it could be missing.
It's a hardy instrument, Harris said, but even if it stopped
working, the safety board can compare its malfunction time
with that of the flight data recorder and air-traffic control
transcripts. That could corroborate evidence gleaned from the
data recorder, which suggests a widespread electrical failure
might have caused the crash.
Transcripts from the voice recorder won't be released, Harris
said, since Canada carries tight restrictions on how its
information can be used and the conversations it records are
considered private. The Transportation Safety Board might
choose to release parts of the transcript in a final report.
Navy spokesman Cmdr. Kevin Carle said diving conditions
were good at the time. Working from the diving tender Granby,
divers will continue looking for wreckage and human remains today.
The discovery came the same day Swissair confirmed the plane
that crashed had recently suffered a short-circuit in a piece of
cockpit electrical circuitry. Also yesterday, Boeing went on the
offensive saying they have had no complaints about a insulating
tape called Kapton, disputing reports the volatile wire insulator
used on the aircraft played a part in the crash.
In New York, hundreds of United Nations officials gathered at
a memorial to mourn the death of nine workers killed in the crash.
Also yesterday, a Swissair plane heading to New York with 151
people on board was involved in a near-miss yesterday with a
KLM jumbo jet over Ireland. Swissair spokesman Erwin
Schaerer said a collision was avoided thanks to electronic warning devices.
_____________________________________________________________________
Friday, September 11, 1998
Plane besieged by electrical problems
By RICHARD DOOLEY -- The Daily News
The five final minutes recorded by Swissair Flight 111's flight
data recorder showed the plane was besieged by a number of
worsening electrical problems that might have affected the
pilot's ability to control the aircraft.
"The flight-data-recorder team in Ottawa has determined that a
progressive number of parameters exhibited anomalies in the
five final minutes of the flight recording," said Transport Safety
Board chief investigator Vic Gerden.
The anomalies are fault codes picked up by the recorder's
on-board computer generated by various electrical systems in
the aircraft.
The aircraft's electrical system, called avionics, will now come
under scrutiny by the safety board as it tries to piece together
the plane's last moments.
Gerden said the sequence of fault codes picked up by the
flight-data recorder is being analysed by a team of experts to try
and pinpoint the cause of the faults and when they started.
"We have not yet had enough time to understand the
significance of the sequence and pattern of these fault codes
developing," Gerden said.
Electrical maintenance scrutinized
Investigators are looking at the maintenance history of the
airplane, especially the electronics work.
Gerden said it is too early to know if the plane had a history of
electronic problems.
Investigators are hoping the recovery of the cockpit voice
recorder might yield clues to electrical problems aboard the
Boeing made MD-11 as it plunged into the sea off Peggy's
Cove Sept. 2, killing all 229 on board.
It's likely transcripts of the voice recorder will not be made
public, Gerden said.
Divers have located the second of the so-called black boxes,
but rough weather in the search zone has prevented its recovery.
Sonar sweeps of the search area has turned up more wreckage,
lying in about 54 metres of water. An engine cowling and two
wheels have been spotted using side-scan sonar and remotely
operated video cameras.
Three large sections of fuselage will likely be the target of
diving and recovery operations today and tomorrow.
The lifting of the larger sections of the aircraft by the United
States diving ship U.S.S. Grapple will depend on the removal of
any human remains still inside.
Canadian navy Capt. Phil Webster said diving operations are
prepared to work around the clock.
"Our priority is still the recovery of human remains and the
voice recorder," he said.
Investigators have also been able to identify the last moments
of the aircraft as it was recorded on the air-traffic-control audiotapes.
Crash recorded by seismographs
The last radar contact of the aircraft made with its automatic
transponder was recorded at 9,700 feet at 10:26:04 p.m. as it
was travelling at around 445 kilometres an hour.
The final radar contact with no transponder was recorded five
minutes later at 10:31:07 p.m.
The flight-data recorder also failed to record the last six minutes
of the plane's flight. Gerden said the investigation team will try
and match the times of the recorder failure and the radar
transponder failure.
Investigators checked with Geological Survey of Canada, at the
Bedford Institute of Oceanography in Dartmouth, to see if
seismic equipment there recorded the impact of the plane
striking the ocean.
"They confirmed that the seismographs recorded a peak event
at 10:31:22 hours local time," Gerden said.
"That peak event was detected as coming from the direction of
Peggy's Cove." Gerden said that is a good indication of the
precise time the aircraft hit the water.
Gerden said a buoy anchored off a shoal near the search zone
at the mouth of St. Margaret's Bay was not struck by the
crashing jet as it descended as earlier theorized.
Sweeps of beaches have been expanded to include
Lawrencetown and Conrod's Beach on the Eastern Shore. The
main focus of the ground search will concentrate on the
Mahone Bay and St. Margaret's Bay areas.
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