DEFECT PUTS MANY SMALL PLANES
AT RISK
Author(s): Matthew Brelis, Globe Staff Date: December 19,
2001 Page: A1 Section: National/Foreign
It was supposed to be a trip to make a lifetime of memories:
three grandmothers from the blue-collar community of
Everett, north of Boston, spending a week in Alaska,
highlighted by a plane ride around Mount McKinley, North
America's highest peak. But for two of them, it was their last
trip.
Seconds after the mountain-bound Cessna 206 seaplane
lifted off the surface of Lake Hood in Anchorage on Sept. 23,
1996, the throttle control arm, which controls the power
produced by the engine, failed. Just when pilot Nels
Kasperson needed power, the engine idled. He tried to reach
nearby tidal flats, but before the water's edge, the plane
became entangled in high tension wires, crashed, and burned.
Kasperson and two of the three friends from Everett -
Dolores McLaughlin, 68, and Joan A. Keefe, 64 - were killed.
The third woman, Carmella Vetrano, then 75, was injured,
along with another passenger.
The crash was not the first to occur under similar
circumstances. The throttle control arm, a critical part used
in thousands of Cessnas and other small airplanes, has a
history of failing, causing the engine to lose power. This has
resulted in dozens of reported failures of the part, more than
a dozen crashes or forced landings, and at least three deaths,
according to a review by The Boston Globe.
Over the last 10 years, pilots and some of the Federal
Aviation Administration's own inspectors have urged the
agency to issue an order fixing the problem, but the FAA has
not done so, instead recommending that owners check the
throttle arm for wear.
Critics charge that the Alaska crash and others like it
represent a regulatory failure and a shirking of corporate
responsibility. Both Cessna, the largest manufacturer of
small airplanes, and Teledyne Continental Motors, the
manufacturer of the engines, have been aware of the problem
at least since the 1980s, according to aviation officials.
The two companies have blamed each other for the bronze
throttle arm's tendency to wear quickly. But neither
company has fixed the flaw at the precise juncture where the
airplane - Cessna's responsibility - meets the engine -
Teledyne's responsibility. It is in that gray area where each
company has pointed a finger at the other, and where the
problem remains unsolved.
Cessna officials say more than 1,000 of their aircraft have the
part, and Teledyne officials say they have produced about
175,000 engines in the last 50 years with bronze throttle
arms. Teledyne has declined to accept Cessna's
recommendation that the part be made of steel, a stronger
material less likely to wear quickly.
One frustrated FAA inspector said the part has not gotten
the appropriate scrutiny from the agency or the
manufacturers because not enough fatalities have occurred to
focus attention on the problem.
"You've got to remember, if the manufacturer makes a
change to the design or material in a critical part, they are
saying the other one was not adequate and their liability is
way out there," the inspector said, speaking on condition of
anonymity. "The difference between general aviation and air
carriers is the number of body bags. You get enough body
bags and Congress gets word of it. You get one or two bags,
who really notices it? You don't put up a stop light at an
intersection until so many people are killed."
Both firms familiar with part's troubled history
The throttle control arm is a small, angled part made of
bronze that weighs less than a pound and can fit in an adult's
hand. It is one of thousands of parts in an airplane, and the
federal government approves every one of them.
When McLaughlin, Keefe, and Vetrano boarded the
19-year-old Stearns Air Alaska Cessna 206 for their
sightseeing tour, they had no way of knowing that the throttle
control arm used by Teledyne had a history of failing. But
Cessna and Teledyne were both aware of the troubled history
of the part. There have been at least 25 failures of the
throttle arm reported to the FAA since 1975. Some were
discovered in routine maintenance, but at least 15 times
planes were forced to make emergency landings prior to the
fatal accident in Anchorage, and on at least two occasions
since, according to a Globe examination of the role of the
control arm in aviation accidents. The reports to the FAA,
however, are voluntary, so the number could be higher.
Both the FAA and the National Transportation Safety
Board found that the failure of the part caused the
Anchorage crash, although why it failed remains in dispute.
More than a year before the crash, Cessna urged Teledyne to
start making the bronze arm out of steel - as does Textron
Lycoming, the other main manufacturer of small-plane
engines - but that request went unheeded. Cessna and
Teledyne had been partners for decades, and there was no
love lost between the two. When Providence-based Textron
bought Cessna in 1992 for $600 million, it switched to using
only Textron Lycoming engines in new Cessna single-engine
aircraft.
Teledyne Continental Motors, a subsidiary of Los
Angeles-based Teledyne Technologies, Inc., countered that
if the part was wearing, it was due to Cessna's design of the
linkage - a rod with several washers and bolts - that
connects the throttle cable to the throttle control arm.
Teledyne also said some of the mechanics servicing the
thousands of engines in the field were to blame for not
making certain the connection was tight.
Both manufacturers suggested that aircraft owners check the
part for wear or looseness, Teledyne saying it should be done
every 100 hours, and Cessna recommending every 50 hours.
But the part failed in one accident just 20 hours after being
installed, according to the accident report. And a Cessna
official, in a deposition, acknowledged that Cessna had heard
of the part failing in at least one other case after just 10 hours
of flight.
Cessna officials refused to comment on the throttle-arm
issue.
John Barton, chief technology officer for Teledyne
Continental Motors, said if the connection is properly
tightened, the arm cannot wear. He likened it to the lug nuts
on the wheel of an automobile. Only when the nut, or
connection, is loose, Barton said, can the arm wear.
As recently as February, the FAA said in an advisory notice
to pilots, mechanics, and aircraft owners that a pilot of a
twin-engine Beech 58 had to make an emergency landing
when the Teledyne throttle arm failed on one engine. It said
"all involved personnel are encouraged to give close attention
to the throttle lever during scheduled inspections and
maintenance."
FAA spokeswoman Laura Brown said the agency believes
poor maintenance, rather than design problems, leads to
rapid wear of the throttle control arm.
But according to mechanics, such maintenance is difficult,
especially on single-engine Cessnas, because the throttle arm
is near the firewall and a mechanic needs to use a mirror to
check for play. A spokesman for Beechcraft, another large
manufacturer of small planes, said if the part fails on its
aircraft, there is a spring which automatically restores power
to the engine.
Settlements don't fill void left by deaths
The voids left in the McLaughlin and Keefe families by the
sudden violent deaths of their matriarchs can never be filled,
relatives say. A six-figure settlement for each family from
both companies did nothing to assuage the loss.
"You never want them to have the satisfaction of thinking
that a check was acceptable," said Michael McLaughlin, a son
of Dolores McLaughlin. As part of the settlement, the
McLaughlins and Keefes instructed their attorney, David
Hass of Malden, not to agree to any confidentiality provision.
Even though the final settlements were reached late last year,
some of the McLaughlins and Keefes intend to speak out on
the troubled history of the part and the inability of either
company to agree on a course of action to rectify the
problem.
While engines built for Cessna since 1996 by Textron
Lycoming do not have the throttle control arm problem,
company officials estimate there are at least 1,000 older
Cessnas still in operation that do. But a spokesman for the
Cessna Pilots Association, a California-based group
unafiliated with the company, says the number is at least 10
times that high.
Some attorneys are concerned that a 1994 law enacted by
Congress, the General Aviation Revitalization Act, was
designed to support the general aviation industry by limiting
the civil exposure plane manufacturers face from lawsuits.
The law places an 18-year window in which a claim can be
brought. In general, if a plane, or part, is older than 18 years,
a company would not be held liable for damages if a
mechanical problem caused the accident.
"While I am not privvy to what goes on in board rooms of
these corporations, clearly GARA and its statute of repose
does not encourage doing a recall," said Boston attorney
Anthony Tarricone, who represented Carmella Vetrano in
the lawsuit against Cessna and Teledyne. "I would think there
would be some financial incentives to leaving some problems
alone."
Indeed, in the case of the Alaska crash, Cessna argued that
the plane, which was built in 1977, was old enough to make
the claim against the company void under GARA.
But in 1979, Cessna changed the bolt that attached the
linkage rod to the throttle control arm "out of an abundance
of caution," one Cessna official recalled in a deposition for
the Alaska lawsuit. The new type of bolt was installed on the
plane that crashed in 1986 and that change enabled
Tarricone and Hass to successfully argue against Cessna's
motion for summary judgment because the new bolt was less
than 18 years old.
"Clearly, there is not an incentive to redesign a part on an
aging aircraft," said Tarricone.
"It is unconscionable what these two companies have done,"
said Michael McLaughlin. "They had a part that was bad and
they said it was someone else's fault. They did not do the
right thing and they screwed things up for everyone."
Paula Kasperson, the Alaska pilot's widow, said not enough
attention has been paid to the throttle control arm problem.
"My personal belief is that there are a number of people who
are still in danger and the word has not gotten out about the
part," said Kasperson. "The FAA has not done enough to get
the word out. This was a disaster waiting to happen and
unfortunately, the body count is not big enough for anyone to
move. There is no reason in the world for Nels or any of
those women to be dead. This had happened many times, but
they were the first ones to die."
Accident reports not verified by FAA
Federal records going back to 1975 show there have been 25
reports of the throttle control arm on Teledyne engines
failing at the bolt hole - the point where the arm attaches to
the throttle cable - as early as 1976, and as recently as 1998.
But the reports, known as service difficulty reports, are not
required to be filed with the FAA and are not verified by the
agency for accuracy, so the number of incidents could be
much larger.
George Heath, a former aviation accident investigator for the
Transportation Safety Board in Canada, investigated the
emergency landing of a Cessna 210 in Edmonton, Alberta, on
May 22, 1987, when the plane lost power as it prepared to
land.
The pilot made a forced landing in a field, the right wingtip
struck the ground, spinning the airplane, collapsing the
landing gear, and rupturing a fuel tank. All five people on
board escaped shortly before the fuel ignited and fire
consumed the aircraft.
A new throttle control arm had been installed 20 hours
before the crash, with a Teledyne-approved steel insert
imbedded in the bronze arm designed to prevent wear. But
the Canadian investigative report found the steel insert in
the arm "had caused rapid wear and separation of the
control."
"The whole purpose of doing these investigations is to
identify the cause and get a chance to prevent it from
occurring again," said Heath. "I was dumbfounded when I saw
the throttle arm [from the 1996 Alaska crash]. It looked
exactly the same. And obviously the manufacturer was aware
of the problem because they participated in our investigation.
To see it happen again, and have people die, is really so
disheartening."
Heath said the design of the Teledyne throttle arm should be
changed. "It is a bad design. Everyone else can make an arm
that does not do that."
More than two years before the crash that killed Keefe,
McLaughlin, and Kasperson, Dennis DeLeo, a doctor in
Alaska, had a similar experience using a Cessna 206 with
floats. On July 18, 1994, DeLeo was flying two passengers on
a 90-minute trip south of Anchorage when the engine lost
power at 3,500 feet, and he was forced to make a crash
landing on the tundra. No one was injured.
DeLeo paid to have the airplane taken by helicopter to a
maintenance facility. "The FAA came and inspected the
plane and they found that the throttle cable where it attaches
to the throttle arm had pulled through the arm. The steel
bushing had worn through the arm and pulled out, and the
arm went to idle."
DeLeo said the only person who seemed interested in the
part's failure was Ernie Keener, an FAA maintenance
inspector. "He was working with [Teledyne] around
redesigning the throttle arm itself and the linkage [Cessna's
responsibility]," DeLeo said.
Keener was unable to get the FAA to issue an airworthiness
directive, but he did try to resolve the problem. He collected
some worn throttle control arms from accidents and some
from facilities where preventive replacements had been
made, then sent them to Teledyne, asking the company to
make them out of steel.
"I had several conversations with the engineers back at
[Teledyne] on this," Keener said. "As far as safety
recommendations to improve the product, I never got any
response out of them. And they were aware of it back in the
1980s. I was a general aviation inspector up in Alaska for 15
years and I probably had 25 of those worn parts. . . . I also
tried to chase it down the AD [airworthiness directive]
avenue, but I got no support."
As the NTSB noted in its investigation of the 1996 Alaska
crash, another factor that makes the failure of the throttle
arm so dangerous is that in Cessnas, there is no "fail-safe"
mechanism, like a spring, to automatically increase the
throttle setting if the cable fails or becomes disconnected. A
reduction to idle power is similar to taking your foot off the
accelerator in a car going 60 miles an hour. In an airplane,
such a reduction in speed can be catastrophic.
Walter Haag, an accountant from Fall City, Wash., was flying
back from his San Juan Islands vacation home in the Pacific
Northwest aboard his Cessna 206 on Sept. 18, 1994. He and
his wife had just taken off from Center Island when the
engine idled, and he had to crash land in a field.
"I smashed my face on the dash and was spitting out teeth,"
Haag said. He was not otherwise injured, nor was his wife.
The NTSB determined the cause of the crash was failure of
the throttle control arm, and found it had not been
sufficiently tightened, pointing to a human error.
"I filed a service difficulty report with the FAA," said Haag.
"I found 17 other instances of the exact same thing."
He wanted the FAA to issue an airworthiness directive - the
most stringent notice the agency issues because it mandates
action, unlike advisory circulars or bulletins that provide
basic guidance. But the FAA declined.
Nonetheless, Keener and some of his fellow inspectors in the
FAA now take every opportunity they can to educate
mechanics and pilots about how the throttle arm can fail.
Said one inspector still based in Alaska, where private planes
are used widely, "The problem has gone on for a long time.
What we have done here is whenever I get a chance, and I see
anyone who operates a Cessna 185 or a 206, I corner them
and I tell them what I know about throttle arms. And they
are always very grateful."
Companies at odds over arm's shortcomings
Both Cessna and Teledyne have tinkered with the linkage
and the throttle arm over the years.
Teledyne engineers changed the design of the arm itself. In
1979, they added a steel bushing inserted into the soft metal
arm to prevent wear. That same year, Cessna changed how
the linkage attached to the arm. In the past, engineers had
favored a self-locking nut, but they opted to use a different
type of nut with a cotter pin to keep it in place.
Then in 1995, the two companies exchanged letters on the
throttle control arm issue.
Richard Evans, the group leader for propulsion at Cessna,
wrote to John Barton, the Continental engineer, on June 27,
1995.
"Cessna has recently received reports of the throttle control
becoming separated from the engine throttle arm on 200
series aircraft," Evans wrote. "Investigation has revealed that
the bolt hole in the arm is egging [wearing] to the point
where the tip of the arm fails and the control becomes
disconnected from the arm. This situation appears to be
aggravated by the soft brass material, and with the
combination of the steel insert and soft arm material,
possibly the condition is accelerated more. . . . Cessna is
requesting that the throttle arm material be changed to steel
with no insert at the arm end. This would permit elimination
of the special repetitive inspection."
On Aug. 15, Teledyne wrote back, saying it was Cessna's
linkage design or sloppy mechanics that were to blame, not
the material of the bronze throttle arm.
"We have supplied all of our fuel-system levers made from
this material for many years and it has been shown to be
entirely adequate for these applications," wrote Al Beech,
director of engineering service programs. Beech said the
wear resulted from "insufficient tension" at the connection
and said Cessna should go back to the orginal self-locking
nut, and not use the one with the cotter pin.
"They both recogninzed that the connection as it existed was
inadequate and prone to failure, but rather than accept
responsibility, they pointed the finger at each other," said
Tarricone, Vetrano's lawyer, who obtained the memos
through discovery proceedings in his lawsuit against the
companies. "Neither does anything and they both let the
stalemate stand."
On Jan. 26, 1996 - eight months before the Alaska crash -
Cessna sent out a notice, indicating that Teledyne had
increased the thickness of the bronze arm, and filed down the
end where the linkage attaches to ensure a better fit. Cessna
said installation of the new arm was not mandatory. And
Barton, the Teledyne engineering chief, testified in a
deposition that making the arm thicker was not done to
prevent wear at the end of the arm where the linkage
attaches, but to prevent the arm from breaking at the other
end.
Less than a month after the Alaska crash, alarmed local
FAA officials submitted a three-part "recommendation for
accident prevention" to Washington headquarters calling for
a series of airworthiness directives to require the 100-hour
inspection on the throttle arm; to make certain that
appropriate torque is used to ensure no movement between
the linkage and the control arm; and to change the design of
the throttle arm, "particularly on the [Teledyne]
fuel-injected engines, to increase the safety factor on these
parts. A safer design could include more material thickness
and edge distance at [the] attach hole area, and a change from
bronze to steel, or other appropriate material."
But after consulting with Cessna and Teledyne to determine
the frequency of the problem based on their
service-experience data, FAA officials in Washington
concluded that changing the design was not necessary, said
Brown.
"We have been expecting to see an AD [airworthiness
directive] on the throttle arm ever since that report was
filed," said one Alaska FAA inspector. "If you can find out
where the disconnect is, will you let me know?"
Trip was to be dream of a lifetime
For Dolores McLaughlin, Joan Keefe, and Carmella Vetrano,
the trip to Alaska was part of the national convention of the
Emblem Club, a women's affiliate of the Elks.
"For four years, I listened to my mother planning this trip,"
said Keefe's son, Michael.
"These were nice grandmothers from Everett who would get
together and make baskets for Christmas," said Hass, the
McLaughlin and Keefe family lawyer. "For them to die in a
single-engine plane crash in Alaska is incredible."
The plane, fully loaded, took a long time to take off.
Witnesses said it reached about 100 feet before starting to
fall. Kasperson tried to head for tidal flats, but then the plane
became entangled in high-tension wires, like a fly caught in a
spider's web.
"We just hit the wires and I said, `Oh no, no. Here we go
again,' because I had just been in a car accident," Vetrano
recalled. "Nobody looked at each other. Everyone was
frightened."
One of the wires broke and soon a ball of fire exploded
through the plane, which plummeted some 50 feet to the
ground.
Vetrano said she struggled with her seat belt as the fireball
roared through the plane. She turned to her right to shield
herself, and the left side of her body was badly burned. "I
asked God for help and the next thing I knew I was on the
ground."
Hospitalized in Anchorage and Boston for more than a
month, Vetrano went through painful skin grafts because of
burns to the left side of her body. She would not comment on
her settlement, but it is standard in such cases for injured
survivors to receive more than the relatives of the dead.
"Dolores and I were friends for many years and Joan was my
newfound friend," Vetrano said. "I still go to Emblem Club
meetings, but it's not the same."
Matthew Brelis' email address is brelis@globe.com