N.C. Plane Crash Raises Weight Concerns
January 20, 2003
By THE ASSOCIATED PRESS
Filed at 5:21 p.m. ET
CHARLOTTE, N.C. (AP) -- Flying too close to the known
limits for a plane's weight and balance can have
catastrophic consequences for a commuter aircraft -- as the
crash that killed 21 people in Charlotte earlier this month
may very well have shown.
Investigators have yet to establish the cause of the crash
of the US Airways Express turboprop, which went down at the
airport Jan. 8 after taking off at an extremely steep
angle.
But they are focusing on the possibility that heavy takeoff
weight and improper weight distribution combined with a
malfunctioning elevator, the tail assembly that controls
the plane's pitch, to cause the accident.
The tragedy has focused attention on how the industry
calculates the weight of its passengers and cargo. And it
has raised questions about whether that method is realistic
in this land of expanding waistlines.
``I think it's one of the things that may make commuter
flying riskier, especially when you're flying with a loaded
airplance -- the possibility that it could be out of weight
or out of (balance) because of variations in the average
passenger weight and the distribution of weight,'' said Jim
Burnett, a former chairman of the National Transportation
Safety Board.
Among the weight and balance concerns:
-- The plane was full, with 16 men, two women and one child
among the 19 passengers. Air Midwest, the airline that
operated the flight, assumes -- with Federal Aviation
Administration approval -- that passengers flying in winter
average 175 pounds each, including clothing and carry-ons.
But given the super-sizing of American waistlines (adult
men averaged 180.7 pounds in 1994, the most recent year in
which statistics from the Centers for Disease Control and
Prevention are available) and the increased size and weight
of carry-ons, that standard could have been exceeded on the
flight.
-- Investigators have said the plane's captain and a member
of the ground crew debated before takeoff whether the
flight was overloaded.
John Goglia, the NTSB member who headed the crash scene
investigation, said a ground crew member believed the plane
was limited to 26 bags. Goglia said Capt. Katie Leslie
decided that all 31 checked bags could remain on board. He
said pilots and others interviewed during the investigation
thought the plane ``looked heavy'' as it prepared for
takeoff.
Air Midwest assumes -- again, with FAA approval -- that
each piece of checked baggage weighs 25 pounds on average.
But some in the industry believe that estimate is too low.
In the Southeast, for example, many travelers bring along
their golf clubs, which can weigh well over the estimate.
Also, commuter airlines often deliver passengers to
big-city airports to catch international flights, for which
travelers are likely to pack heavy. (That was not the case
with the Charlotte flight, which was headed for Greer,
S.C.) It is also believed that many passengers are packing
more in their checked luggage these days because carry-ons
are so closely screened.
The maximum takeoff weight for the Beech 1900 that crashed
in Charlotte is just over 17,000 pounds. The NTSB has said
that, according to the plane's documentation at least, it
was within 100 pounds of that weight.
As for its weight distribution, Goglia has said that on
paper, at least, the plane was within 1 percent of the
rearward limit for its center of gravity. (The more luggage
that is put in the back of the plane, the farther to the
rear moves the plane's center of gravity. Flight rules
specify the farthest allowable point.)
Given those conditions, said Paul Czysz, a professor
emeritus of aviation and engineering at St. Louis
University, a miscalculation could have easily made the
plane unbalanced. For example, too many bags in the rear
baggage compartment or several heavyset men seated in the
rear could have upset the balance.
Czysz and others said that airplane weight limits generally
have a built-in safety margin, much like the ``empty'' line
on automobile gas tanks. ``You could be 10 percent over the
weight limit of an airplane and still fly it,'' Czysz said.
But the location of a plane's center of gravity is not as
forgiving. The FAA says a pilot may not fly a plane if its
center of gravity is beyond its forward or aft limit,
because such a plane can be uncontrollable once airborne.
``It's a very black-and-white thing,'' Czysz said.
Mary Schiavo, a former inspector general for the U.S.
Transportation Department, said margins of error are thin
in commuter planes like the 19-passenger Beech 1900.
``The small plane, being so light, you don't have a lot of
leeway,'' said Schiavo, now a Los Angeles-based lawyer who
litigates air disaster cases.
Schiavo said calculating an aircraft's weight and center of
gravity is so crucial that it is one of the first things
prospective pilots learn to do in flight school.
``You don't touch the aircraft until you learn to do weight
and balance,'' she said. ``Pilots know that this can make a
difference on having a successful flight or not.''
A small-plane crash in the Bahamas that killed singer
Aaliyah and eight others in 2001 was blamed in part on a
plane that was overloaded by at least 700 pounds.
David Stempler, president of the Washington-based Air
Travelers Association, a passenger-advocacy group, said he
has heard for years from commuter pilots concerned about
weight and balance. Last week's crash heightened worries,
he said.
``I think what we need to do for planes under 30 seats is
weigh all checked and carry-on bags that go into the cargo
compartment,'' he said.
The industry would probably resist change. Airlines are
already losing money; telling them they must reduce the
number of passengers or the amount of cargo could further
harm the industry.
Passengers already dealing with stepped-up security
screenings might not want to put up with the indignity
being weighed before boarding, and studies have shown
people do not accurately report their weight.
And in-ground scales that weigh planes and measure their
weight distribution as they head for the runway --
double-checking the calculations of the pilots and load
managers -- are expensive.
Copyright 2002 The New York Times Company. |
