Lasers to warn pilots in restricted D.C. airspace

This could be generalized to "everywhere".

On the other hand is also represents a "homing signal".
Theoretically overflights of Paris itself are forbidden
but I was two con-trails the other day over the city.

Earl

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Lasers to warn pilots in restricted D.C. airspace

From Mike M. Ahlers
CNN Washington Bureau


WASHINGTON (CNN) -- Beginning in mid-May, pilots who intrude into restricted
airspace over the nation's capital will be warned by pulsating red and green
laser beams, part of a government effort to prevent a terrorist attack.

The U.S. military will activate the ground-based lasers whenever
unauthorized or unresponsive aircraft enter the restricted zone, a huge
swath of airspace surrounding the region's three major airports.

The bright laser beams, which flash red-red-green, are easily seen, even
during daylight or in a sea of city lights. But because the beams are
directional, they rarely will be seen by other aircraft or by the public,
except in hazy conditions. The laser beams can be seen 15 to 20 miles away,
authorities said, except in cloudy conditions.

The lasers are harmless, say authorities, who are quick to distinguish them
from the high-intensity laser pointers that have vexed some pilots in recent
months.

"This is good laser, if you will," said U.S. Air Force Col. Ed Daniel of the
North American Aerospace Defense Command. "It is very eye safe."

Private pilots who have been briefed on the new system generally support it,
but said they don't know if the lasers will work under all conditions. "If
you are flying west in the afternoon and the sun is directly in your eyes,
it will be very difficult to see anything else," said Fayek Zabaneh.

While NORAD would still prepare to launch jet fighters during each
intrusion, a quick response by an errant pilot might keep the fighters on
the ground, saving the tens of thousands of dollars it costs each time jets
are scrambled.

Hundreds of incursions per year

Incursions into the restricted space are common. NORAD officials said there
are typically two or three incursions a day, usually by pilots not familiar
with the restrictions or who stray from their intended flight paths.

The most notable incident occurred during President Reagan's funeral
activities last summer when a jet carrying Kentucky Gov. Ernie Fletcher
entered the airspace with a broken transponder, prompting the evacuation of
the U.S. Capitol.

Following the September 11, 2001, terrorist attacks, the government severely
restricted air traffic in the region. It established an Air Defense
Identification Zone -- an area consisting of a 30-mile diameter circle
around Reagan Washington National Airport and 22-mile circles around Dulles
and Baltimore-Washington international airports.

Pilots in the airspace must communicate with air traffic controllers,
transmit a four-digit identifier with their transponders and take other
measures to let controllers know their identity and intentions.

Restrictions are more severe in a 15.75-mile inner circle called the Flight
Restricted Zone.

"There are so many high-value targets in this area. It is the center of
government. We need to do everything we can to protect it," Daniel said.

Red-red-green sequence

If an errant plane cannot be contacted by radio, authorities would attempt
to get the pilot's attention by aiming the lasers and flashing the rapid
red-red-green signal -- colors chosen because they are easily seen and a
sequence not otherwise used in aviation.

NORAD says that whenever it uses the lasers, it will notify the Federal
Aviation Administration and others through the Domestic Events Network, an
open phone line that connects government agencies charged with protecting
Washington.

Authorities declined to say how many ground-based lasers there are, nor did
they reveal their locations, although that may eventually become apparent to
residents.

Officials refused to give the total cost of the system, but said individual,
costs for unmanned laser sites totaled $500,000.

NORAD developed the system in two years, constructing it from off-the-shelf
technology. There are no plans to put similar systems in other cities,
although it could be considered for locations such as the presidential
retreat at Camp David.

NORAD said that both military and independent medical personnel have
validated the safety of the system.

The military says it considered using spotlights to warn planes, but that
lasers are more discrete and, because they can be aimed at a specific
aircraft, less likely to cause confusion to other planes.

Pilots have been concerned about a spate of incidents involving people who
have pointed lasers at airlines.

The Federal Aviation Administration has announced new protocols, requiring
pilots to report laser lights to air traffic controllers, who will warn
nearby pilots and notify police.

*

Earl Evleth writes:

Theoretically overflights of Paris itself are forbidden
but I was two con-trails the other day over the city.

They used to be forbidden. Apparently the rules changed a few years
ago.

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