AIRPORT SAFETY FEATURE: ; Escape Ramp for Planes; Specialized Crushable Blocks Are Designed to Slow Down a Runaway Jet

By BRAD McELHINNY

DAILY MAIL STAFF

In the middle of the night, no airplanes are landing at Yeager Airport. But it’s still a very busy place. Under the glow of floodlights, forklifts carry heavy blocks to a work crew that’s in perpetual motion, laying a surface meant to save lives.

“Come on! Get down!” yells James Henry, supervisor for Triplett’s Airport Maintenance of Williamstown, the contracting company working each night on the runway.

Henry yells the command every few seconds, instructing forklift driver after forklift driver to lower the blocks that weigh up to 900 pounds. He does his part by leaning into the blocks and shoving them into place.

For the next couple of weeks, that will be the scene every night at the Charleston airport. While most of the city is sleeping, the work goes on from the time the last airplane lands at midnight until 6 a.m. when the airplanes start flying again.

The crew of 18 workers is installing special blocks known as Engineered Material Arresting System on the western edge of the 6,280-foot runway.

As the crew works, the city’s lights glisten below. It’s that spectacular view that has created the need for the construction project.

Because Yeager Airport was constructed on the city hilltop, there’s no easy way to build a modern safety overrun that could give a jet extra room to stop and avoid a potential disaster.

To the rescue is modern engineering. The blocks being placed by the crew are a crushable cellular cement material – which means the blocks seems solid but actually have a lot of air in them – meant to compress under the weight of an airplane.

The blocks are a solid surface for an average person to stand on. But an airplane’s weight would squish the blocks, providing enough resistance to slow a runaway jet enough to keep it on the hilltop.

The blocks are also arranged in a bed so that shorter blocks are toward the front and taller ones are toward the back, making it so the airplane would actually be going uphill.

At least that’s the explanation the experts provide. A typical passenger on a plane would prefer not putting the theory to the test.

“It just breaks down,” said Yeager Airport director Rick Atkinson.

“The thing that people understand best is that it’s like a truck escape ramp: You have sand and gravel out on a truck escape ramp, and you’re going uphill. Once the truck gets into it, the friction just slows it down and it comes to a stop. The concrete is not sand – it’s solid – but it breaks down under the force of the aircraft.”

Back when the community was debating the possibility of building a new regional airport in Putnam County, one argument was that Yeager Airport was so hemmed in by the surrounding mountains that it would be impossible to build a modern safety overrun and meet federal standards.

Atkinson and other Yeager officials started exploring the alternative about seven years ago, not long after the system was installed at John F. Kennedy Airport in New York as a test case.

JFK’s trouble is not mountains but the surrounding bay. There, the system has been used three times in the past decade to stop airplanes. One was an 800,000-pound 747 cargo plane that was landing in snowy conditions, according to the company that makes the system.

Such systems, all manufactured by the Engineered Arresting Systems Corporation of New Jersey, are now in place at 18 airports with installation under contract at six more airports, according to the Federal Aviation Administration.

“This airport definitely needed one of these,” said John Curry, site supervisor for the company, known broadly as ESCO. “There’s a steep drop at the end of this one.”

Curry was standing on a bed of the blocks at Yeager, watching the project take shape. It was cold, breezy and unusually well lit, considering the time was shortly after 4 a.m.

He has a lot of basis for comparison. He has overseen projects as far away as China, where he compared the airport to Yeager’s landscape.

“It was similar to this job,” said Curry, who is from outside Philadelphia. “They moved a mountain and filled a mountain. It’s 11,000 feet above sea level, so it’s a little bit higher than this is.”

Next up for his company are projects in Chicago. There are three beds to be installed there at Midway Airport and another two at O’Hare. Then it’s off to Alaska. And then he’ll be in Madrid.

The crew at Yeager figures to work another full week, as long as the weather cooperates.

The project costs $6 million. Yeager is paying the bill through two funds. One is the airport improvement program, which is federal money for capital improvement projects. The other is the passenger facility charge, a $4.50 fee that passengers pay on the first two legs of every flight.

Atkinson says the cost will be well worth it, should an airplane ever skid out of control.

As long as the system works the way it is supposed to, the airplane would ease to a halt. After a few repairs, the airplane could be back up and flying in a couple of days. Disaster averted.

“You pull the airplane out, and you replace the blocks,” Atkinson said.

Contact writer Brad McElhinny at bradmc@dailymail.com or 348- 5129.

(c) 2007 Charleston Daily Mail. Provided by ProQuest Information and Learning. All rights Reserved.