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In The Clear Equipment Helps Planes Land In Low Visibility

Mon., Feb. 9, 1998, midnight

Technology has lifted the fog at Spokane International Airport.

For years, fog shutdowns at the airport were as common as fussy kids in coach. Today, pilots with the right stuff plop their screaming jets onto the runway when visibility is down to two city blocks.

“Passengers must think we are superhuman,” said Capt. Lyle Parker of Alaska Airlines. “For us not to land in Spokane, it has to be so bad you can’t find your car.”

The difference this winter is a new instrument-landing system that virtually eliminates a longtime obstacle to air travel here.

The technology has been in place at larger airports for almost a decade. Spokane’s upgrade arrived in November.

Inbound aircraft use computers and runway radio signals to find their way through the fog.

“You can almost land before you see the runway,” Parker said.

But not all of the jets and crews coming through Spokane are capable of making the so-called Category 3 landings.

Aircraft need to have the right equipment, and crews must be trained to execute the exact sequences for landing in Spokane.

In the past several months, the system has worked so well some carriers said they wish they’d had it long ago.

Passenger bookings were unusually heavy over the holidays when Cougar fans were departing for the Rose Bowl. Foggy weather settled in, but many of the regular flights kept coming and going.

In previous years, “People would not have gotten to the Rose Bowl,” said Glen English, station manager for Southwest Airlines.

Some charter planes, which weren’t equipped, were held up. But others got in and out without problem.

Alaska and Southwest are leaders in using the seeing-eye technology.

All of Alaska’s aircraft and crews are qualified to fly Category 3 landings under the Federal Aviation Administration’s rules.

Southwest brings only one plane to Spokane a week that is not equipped for fog landings. Every other flight has the capability, English said.

On Horizon Airlines, the smaller Dash 8 planes have the technology, but its larger jets do not.

As for the other carriers operating in Spokane, some of their planes and crews are qualified to make low-visibility landings, and others are not.

Those airlines may juggle schedules in coming months to increase their fogproof flights, airport officials said.

Frequent flyers, including a lot of business commuters, are pleased by the change.

“It takes the uncertainty out of flying,” said Rich Hadley, president of the Spokane Area Chamber of Commerce, who recently made it on a foggy morning to appointments in Seattle.

“The ability to land aircraft on schedule is real important for the image of a community,” he said. “I think that’s an advantage to us from an economic development standpoint.”

For years, commercial carriers have been allowed to make only Category 2 instrument landings in Spokane.

For that category, visibility must be at least 1,600 feet, which is more than a quarter-mile, and the ground has to come into view from 150 feet in the air.

Fog-busting aircraft can land with as little as 700 feet of visibility, which is the length of two football fields laid goal post to goal post.

“Very seldom does (visibility) go below 1,000 feet,” said Denny Locke, airport operations manager.

Fog below the 700-foot minimum is rare and lasts only an hour or two at a time, he said.

That means the airport will keep running during the 30 to 50 days of heavy fog between October and March.

For years, community leaders talked about improving the airport’s reliability during fog outbreaks.

In 1990, former House Speaker Tom Foley of Spokane used his clout to specifically list Spokane in the FAA’s budget for a Category 3 system. The FAA was slow to respond.

Transmitters and landing lights have been in place on the northeast approach to the main runway since 1977, allowing Category 2 approaches.

The FAA wanted to move that equipment to the opposite end of the main runway and upgrade it to a Category 3 system.

Spokane officials argued that the airport needed instrument approaches in both directions for safety reasons, and the FAA eventually agreed, Locke said.

New transmitters and high-intensity landing lights were added for the southwest approach, known in aviation lingo as Runway 3. Some of the lights are imbedded in the center of the runway.

Also, green center lights were installed along the taxi ways to prevent pilots from getting lost between the runway and terminal.

The cost was $2.5 million, including $500,000 in local airport funds.

Pilot Parker said Runway 3 in a foggy landing “is the best in the world.”

That is partly because the terrain leading up to the runway is flat for miles. The plane’s radar altimeter gets consistent readings so the on-board computers can maintain a gentle glide path to an accurate touchdown.

Different jets use different technology for achieving the same results.

The McDonnell Douglas MD-80 uses twin computers for an autopilot system that virtually lands the jet by itself.

Boeing has a newer “fog-buster” technology in which a special see-through screen drops in front of the windshield and superimposes a computer outline of the approaching runway.

The screen allows the pilot to monitor the instrument approach while watching through the windshield for the runway to emerge from the fog.

Alaska Airlines pilots can go as low as 50 feet before making the final decision to land. The pilot must confirm a visual sighting of the runway at that point or the co-pilot will hit a button that sends the plane back to 5,000 feet.

Parker said the visual confirmation is important even though instrument data has been cross-checked by twin computers.

The airlines use flight simulators to learn each runway approach.

At Alaska’s operations center in Seattle, pilots spend days learning how to make the Category 3 approaches, which involve mastery of specific numerical data for each airport and the last-second decision-making.

“If we get to 50 feet and there’s nothing there, there’s no time to goof around,” Parker said. “There isn’t time to say, ‘Can you see it?’ ‘Can you see it?”’

Parker, who has flown for Alaska since 1981, recently moved to Spokane because of the new reliability of the Category 3 approach.

He said Spokane International had a reputation of being a place where “you wouldn’t see an airplane for four or five days.”

Technology has ended those long quiet spells outside the terminal.

As Parker said, “In Spokane’s case, it’s certainly money well spent.” , DataTimes ILLUSTRATION: 2 Photos (1 Color); Graphic: Spokane International Airport’s new fog landing system


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