By Andy Pasztor
Federal aviation regulators are proposing fixes to
midair-collision warning devices installed on nearly 9,000 U.S
airliners and business aircraft, after uncovering a safety problem
during a test flight.
The Federal Aviation Administration's proposed directive, made
public on Monday, seeks to mandate software upgrades to widely used
devices manufactured by a unit of L-3 Communications Holdings Inc.
(LLL)
During a flight test over a busy airport's airspace, according
to the FAA, airborne collision warning systems manufactured by the
unit, Aviation Communication & Surveillance Systems LLC, failed
to properly keep track of all nearby planes. The agency said one
aircraft disappeared for at least 40 seconds from cockpit displays,
which "could lead to possible loss of separation of air traffic and
possible midair collisions."
Despite the proposal's broad sweep, regulators apparently
concluded the problem doesn't pose an imminent safety threat
because they want to give airlines and operators of business
aircraft up to four years to complete the upgrades. Officials of
New York-based L-3 Communications, which previously issued service
bulletins dealing with the issue, couldn't immediately be reached
for comment early Tuesday.
An FAA spokeswoman said the company's so-called TCAS devices are
installed on more than 7,000 U.S. airliners and more than 1,800
business aircraft registered in this country. Less than 100 U.S.
military aircraft also use the affected TCAS devices, which provide
pilots with computer-generated alerts and emergency instructions to
avoid nearby aircraft. TCAS stands for Traffic Alert and Collision
Avoidance Systems.
Other U.S. and European companies manufacture similar systems,
but those aren't affected by the FAA's proposed rule.
The agency's move comes amid heightened scrutiny of airborne
near-misses around the U.S. Prompted by a spate of dangerous midair
incidents in the past year, The FAA months ago began a nationwide
review of air-traffic control procedures and safeguards. More
recently, there has been a focus on controller errors leading to a
surge in midair incidents in the skies over Washington, D.C. And
earlier this year, the FAA, the air-traffic controllers union and
United Airlines pilots agreed to set up the first U.S. program to
jointly collect and analyze voluntary reports about midair
near-collisions.
By shielding participants from punishment, controllers feel that
the current drive to expand voluntary reporting programs and
data-sharing initiatives has contributed to the recent spike in
reports of hazardous midair incidents.
One goal of voluntary data-sharing is to identify crowded
sections of U.S. airspace where operational mistakes--ranging from
altitude deviations by pilots to improper instructions issued by
controllers--occur most frequently. Participants can then devise
various prevention strategies to reduce risks.
The FAA's proposed rule also coincides with ongoing agency and
industry analyses of a different set of reports--previously
supplied by European carriers--highlighting spikes in midair
collision-avoidance warnings in recent years around major U.S.
airports. The sites include Los Angeles, Denver, Dallas and
Chicago.
After analyzing data from more than four million flights,
industry and FAA experts found that such cockpit warnings occurred
many times more frequently over Southern California than any other
busy air-traffic sector in the U.S. Some experts suspect large
numbers of general-aviation aircraft around Los Angeles and San
Diego, combined with FAA redesign of some approach and departure
routes, may be to blame.
Other experts have focused on slight differences between
collision-avoidance technology used by U.S. carriers, versus the
onboard devices generally used in Europe. But the FAA has said it
is too early to draw definitive conclusions.
The National Transportation Safety Board, which investigates
airliner incidents and accidents, earlier this year started
collecting its own reports of cockpit collision-avoidance warnings.
The board wants to make sure that such incidents are promptly and
fully reported, and that relevant radar data and detailed flight
information gets passed on to investigators.