Airport navigation system awaits review
TLS to reduce flight diversions
By MATT FURBER
Express Staff Writer
Construction of a Transponder Landing
System (TLS), a navigational tool designed to help pilots establish a safe
landing approach in marginal weather, is nearly complete at Friedman Memorial
Airport. But, as concrete cures, antennas get final weather stripping and the
metal shack housing the computer hardware buzzes with the first test results,
commercial application awaits final Federal Aviation Administration review.
Advanced Navigation and Positioning
Corporation assistant site manager Richard Tuton applies weather stripping
to wiring on a localizer antenna. The antenna transmits and receives data
between aircraft and the transponder landing system being installed at Friedman
Memorial Airport. Once approved, the system will provide pilots who request the
extra information a precise landing pattern at the airport. Express photo by
Airport officials hope the technology will
improve the reliability of the airport by cutting in half the "minimum decision
height" or the altitude below which pilots can be cleared to make a visual
FAA review of the system is site specific
and exhaustive, said Friedman Airport Manager Rick Baird.
"We need to wait for type acceptance. I am
being optimistic," he said, hoping the system will come on line in early 2004.
"It has been an onerous, laborious process."
Improving reliability of the airport was
not the main aim of installing the guidance technology designed for airports
with difficult terrain, but it is a byproduct of an effort to remedy another
problem, said Airport Manager, Rick Baird.
"In the mid-1990s we had a significant
amount of scud running going on," he said.
Scud running is a pilotís term for an FAA
approved practice originally intended for pilots of small aircraft, Baird said.
It is a low altitude, low angle approach that facilitates a visual landing below
a restrictive cloud ceiling.
Baird said the practice violates the
voluntary noise abatement program initiated to help reduce noise pollution from
aircraft in the valley. Some pilots fly as low as 500 feet above the ground.
"You could not believe a high powered jet
would be flying in such weather to get in here," Baird said. "As far as I am
concerned it is unsafe."
The new system is designed to receive a
transponder signal from approaching aircraft and transmit a recommended approach
pattern to navigation instruments standard on most modern aircraft.
The ease of communication without
requiring aircraft to install new technology is a big selling point, said Pete
Kincaid, vice president of marketing for Advanced Navigation and Positioning
Corporation (ANPC), the company that designs and builds the system.
The system is rated to permit a landing
when cloud cover comes as low as 200 feet above the ground. At Friedman, the
system would be rated for a higher elevation due to the mountains, but that
level has not yet been determined. It will be different for private and
commercial aircraft, said ANPC project manager Rick Vogel, who has supervised
If the cloud ceiling is too low the system
stops giving guidance and pilots must abort an approach, he added.
Pilots flying the largest, most
sophisticated commercial aircraft with the highest category of navigation tools
on board can guide aircraft on automatic pilot through zero visibility "pea
soup," Kincaid said. TLS doesnít have the same level of sophistication, but it
will dramatically reduce the number of flights diverted through Twin Falls when
it comes on line.