Wings Magazine

Near misses at overcrowded airports top safety concern, experts warn

Nov. 9, 2007, Brussels, Belgium - As global air traffic expands at record rates, experts warn that near misses on the ground at overcrowded airports are becoming one of the most serious safety concerns in civil aviation.

November 9, 2007  By The Canadian Press

Nov. 9, 2007, Brussels, Belgium – As global air traffic expands at record
rates, experts warn that near misses on the ground at overcrowded
airports are becoming one of the most serious safety concerns in
civil aviation.

The danger arises when airports try to alleviate bottlenecks by
adding runways. That leads to more taxiways intersecting the
runways, raising the risk of accidental incursions _ where an
aircraft or vehicle becomes a collision hazard by venturing onto a
runway being used for takeoffs and landings.

“Runway incursions are right at the top of our agenda,'' said
Gideon Ewers, spokesman for the International Federation of Airline
Pilots' Associations.

“They are happening more and more frequently as air traffic
increases and older airport designs struggle to cope. Of course most
incursions pass without incident, but when they do occur the results
are very bad indeed,'' Ewers said.


The deadliest disaster in aviation history occurred 30 years ago
as a result of such an encroachment. The ground collision in 1977
between two fully loaded Boeing 747s in Spain's Canary Islands
killed 583 people.

Since then, numerous such accidents have ended in tragedy and
experts are now racing to develop systems to prevent even deadlier

According to Eurocontrol, an average of two incursions take place
each day at Europe's 600 civil airports. And in the United States _
where reporting standards are different _ 182 incidents have been
recorded so far in 2007, compared to 158 last year.

The most serious recent accident occurred on Oct. 8, 2001, when a
Scandinavian Airline System MD-87 on takeoff smashed into a Cessna
Citation which had encroached onto the runway. A total of 118 people

More frequent are close calls like one in July at Ft. Lauderdale,
Florida, where two jets missed each other by less than 10 metres. A
United flight with 133 passengers on board missed a turn on the
taxiway and entered an active runway where a Delta jet was about to
land with 167 passengers.

“In an ideal world you'd have no runway crossings at all,'' said
Paul Wilson, head of Airport Operations at Eurocontrol, Europe's air
navigation agency. “But the reality is that as an airport becomes
busier, it also introduces more sophisticated guidance systems and
procedures to prevent runway incursions.''

A Federal Aviation Administration study found that the
well-designed Washington Dulles airport in the United States had
only four incursions during the period from 1997 to 2000, compared
to Los Angeles Airport with a complex layout of multiple
intersecting runways and taxiways _ which had 29 incursions.

Experts say that when the volume of traffic _ projected to double
over the next 10-15 years _ is taken into account, the potential for
near misses and fatal accidents is growing fast.

“It is a problem that affects just about every airport,'' Wilson

The international pilots' union blames poorly designed airports
as the primary cause of incursions. High traffic density,
complicated operational procedures, nonstandard markings, and poor
comprehension of English among cockpit crew add to the risks.

Although low proficiency in English _ the standard language of
aviation _ plays a major role, foreign pilots also complain that air
traffic controllers in the United States contribute to the problem
by using confusing abbreviations or long and complex instructions.

As a result, the FAA now requires U.S. controllers to provide
clear and explicit taxiing instructions to pilots, including the
exact route to their designated runway and not merely which runway
to use.

In order to minimize future risks, Eurocontrol, FAA and other
national air safety agencies are looking into using advanced runway
incursion alert systems that detect potential collisions on runways
and give advance warning to controllers and pilots.

One such system developed by the National Aerospace Laboratory in
the Netherlands and used at Amsterdam's Schiphol Airport alerts
controllers to potential collisions by flashing labels on their
radar screens together with audio signals. All aircraft and vehicle
movements are depicted in real time on an airport map, unlike
conventional radar which has a lag of several seconds.

And when Schiphol added a new, sixth runway, multiple runway
crossings were specifically avoided, said Bert Ruitenberg, the
airport's operational safety expert. Instead, taxiways to the new
runway were built around the perimeter of existing runways.

In addition, red lights embedded in the tarmac prevent planes
from entering an active runway. Ruitenberg said such stop lights
should become standard airport equipment.


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