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"Feds raise alarm on airplane icing"
- From: "Stephen Irwin" <stepheni@xxxxxxxxx>
- Date: Thu, 27 Jan 2005 14:57:17 -0600
Monday, January 24, 2005
Feds raise alarm on airplane icing
Even small buildup on wings can cause lighter craft to crash
By Ann Imse
The Denver (CO) Rocky Mountain News
Federal crash investigations have made repeated calls for tougher rules and
more research on flying in icing conditions because 135 planes have fallen
out of the sky since 1993 because of ice.
And with 171 people dead, the National Transportation Safety Board is not
happy with the slowness of the Federal Aviation Administration's response to
pleas for action dating to 1996.
Today, smaller personal and corporate planes continue to be particularly
vulnerable to ice. Investigators are considering ice as a cause in two
recent fatal crashes in Colorado and Wyoming.
"Icing has always been a major concern," said Dan Bower, an NTSB engineer.
"It's been on our most- wanted list (of aviation safety improvements) for
But the safety board can only recommend changes in the rules. It must wait
for the FAA to conduct research and write new regulations.
In this case, the NTSB has been waiting seven to nine years for the FAA to
act on four safety improvements concerning ice. The board wants more
research, changes in aircraft design and testing, and clearer rules for
The FAA says it has been working hard and making progress, but that the
research is complex and slow.
"It's not just an overnight issue," said the FAA's icing expert, Gene Hill.
He could not predict a date for the issuance of new regulations.
Just last month, the NTSB raised its level of alarm about ice, with two more
On Dec. 15, it issued a public warning, and requested FAA action, on the
extraordinary number of icing accidents involving Cessna Caravans, a
turboprop plane that can carry up to 14 people.
On Dec. 29, it issued an alert to all pilots, telling them to run their
hands over the wings of their planes before takeoff to check for invisible
ice. The alert warned that ice crystals as tiny as grains of salt scattered
on a wing can be dangerous, cutting a plane's lift by one-third.
"We've seen a string of accidents, all related to icing," explained Bower.
That includes ice that collects on the plane while it's on the ground, and
ice that sticks to the aircraft in flight, he said.
Pilots of small and medium-size aircraft are repeatedly running into icing
conditions that they or their aircraft can't seem to handle, he said.
The NTSB's sharp warnings started after ice caused two deadly accidents in
1992 and 1994: a US Airways Fokker F-28 crash on takeoff at New York's
LaGuardia Airport that killed 27, and an American Eagle crash at Roselawn,
Ind., that killed 68.
The airlines responded with stringent rules on when their planes must
de-ice, and sometimes, de-ice again, NTSB and FAA officials said.
Since 1994, no large U.S. airliner has had a fatal crash due to ice.
All 85 deaths due to ice since then have been in small to medium-sized
planes - commuter airliners, general aviation planes and air taxis. The last
category includes corporate and charter planes.
Larger jets have several natural advantages, Bower added. For one, they fly
in the icing danger zone - below 20,000 feet - only when taking off and
landing. Smaller planes, on the other hand, may fly an entire trip in that
zone, Bower said.
John Clark, the NTSB's head of aviation safety, said many pilots have seen
their aircraft continue to operate while contaminated with ice - even a
ridge of ice extending forward off the leading edge of the wing - and they
seem to be learning the wrong lesson from this, he said.
"You can apparently get away with it fairly often," he said. But even if the
chance of crashing is only one in 100, "that's not good odds," Clark said.
The NTSB wants the FAA to conduct more research into the effects of ice on
flying, and then to order changes in aircraft design.
Among other things, investigators have warned the FAA that turboprop
transports that do not have slats to adjust the wing seem to be particularly
susceptible to ice. Few corporate jets or small planes have slats, Clark
said. Large airliners typically do.
The board also would like to see new equipment that can detect ice as soon
as it begins to form while in flight. Now, pilots may not know they're in
trouble until enough ice accumulated to see it out the window or when they
can feel it affect the control of the plane.
"We'd like the detection to give that pilot an extra two or three minutes,"
so he can fly out of the dangerous weather, Clark said.
Some planes fight icing with equipment that warms the wings' leading edges.
Others have "boots," which can balloon slightly to break off ice. Such
devices help, Clark said, "but it's not something you want to bet your life
The FAA's icing expert, Gene Hill, said his agency has been funding
extensive research on icing for years.
First, researchers had to learn more about the formation of ice under
different weather conditions. Then, they had to devise new tools, such as
recalibrated wind tunnels and computer programs that can predict ice
formation. Only when they're past that point can they test aircraft designs
for their reaction to ice and write rules to fit, he said.
So far, the FAA has found that the danger of ice varies dramatically with
the shape of the wing, according to the agency's annual report on research.
And the solutions will vary, Hill added. For example, a type of de-icing
fluid that protects an airliner traveling at hundreds of miles an hour might
stick and contaminate the wing of a slower plane, he said.
Cost and practicality are also issues. "You have to recognize that these
pilots are out in the bush somewhere and they don't have de-icing trucks,"
"We see an end point," in all this work, Hill said. But he declined to give
a date when the FAA would be ready to take action.
In the meantime, pilots are running into serious problems.
The NTSB issued its special warning about the Cessna Caravan in December
after it counted 26 crashes and near-accidents involving ice from 1987 to
2003, resulting in 36 deaths. The board said this caused concern about "a
possible systemic problem with the airplane's design or operation."
Some 1,400 Caravans have been sold since 1984 for use as small commuter
airliners, cargo and bush planes, and for individuals seeking the
"have-it-all" lifestyle, as the Cessna Web site says.
In 10 cases, Caravan pilots didn't sufficiently remove ice before takeoff,
the board said. In 15, ice accumulated during flight, sometimes even in
weather thought safe from icing. In the last case, the timing of the ice
accumulation was not determined.
In one incident, the pilot managed to land even though ice covered his
de-icing boots, parts of the wing and all of his windshield. He had to look
out the side window to see the runway.
Investigators interviewed 22 Caravan pilots in Alaska and found a
distressing amount of ignorance about the plane's limitations in icing
The NTSB recommended that the FAA review its own monitoring of Caravans and
require seasonal pilot training and better recommendations from the
manufacturer for flying Caravans in conditions where icing is possible.
Hill said the FAA made some changes in Caravan training several years ago,
but the safety board said the accidents continued. Since the new alert in
December, the FAA has met with the safety board and Cessna, and it is
considering other actions.
Cessna spokeswoman Jessica Myers said the company is cooperating with the
officials "to ensure that our operators have the best training in the
industry." She said that any change in aircraft design spurred by icing
research would likely affect the entire industry.
The FAA's Hill also said that in reading the icing accident reports for all
kinds of planes, it's clear that some pilots are taking off even with frost
on the wing, or half an inch of snow.
"Those are pretty blatant issues, judgment issues," he said. "You could
argue that the safety record shows that some of these pilots don't have the
background and information. Otherwise, they would have been making better
Hill said the FAA has discussed requiring more extensive training on icing,
but declined to give specifics.
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