It’s been years since the Bremerton National Airport has shut its runway down for realigning true north.

But that’s what’s planned for Aug. 19, weather permitting.

“The long-range forecast is good,” said Fred Salisbury, director of airport operations for the Bremerton National Airport. “So we’re hoping it’s right.”

Beginning at 7 p.m. Monday, Aug., 19 through 7 a.m. Wednesday, Aug. 21, the runway will close for removal and replacement of designation numbers and re-striping.

According to Salisbury, this is the first time that’s been done since the Port of Bremerton took over the airport from Kitsap County in 1963.

It all has to do with where the true magnetic north is, he said.

“The true magnetic north is always changing,” he said. “Because of the shifts in the molten iron at the core of the earth, true north moves at about a degree every five years.”

So currently, the south end of the runway has a 60-foot tall “1” painted on it that signifies a 10-degree reading on the compass. And, he said, a “19” at the north end, signifies 190 degree.

But since those numbers were painted in 1963, there’s been about a 10 degree shift, meaning the numbers have to be changed.

Today, true magnetic north at the airport is closer to 20 degrees at the south and 200 degrees at the north.

Hence, the “1” will become a “2” and the “19” will become a “20.”

Painting will be the second step as early as Tuesday morning. On Monday evening after the airport closes, a subcontractor will begin blasting off the old paint and then the surface will be allowed to dry.

Painting will follow using rollers and brushes and trucks outfitted to do the striping, all of which will result in more than 102,000 square feet of reflective white paint being put down.

The project’s been in the works for several months and the Federal Aviation Administration will foot most of the bill, at $121,000. The port’s 10 percent is $12,086 and is allocated in the current year’s budget.

Notice has gone out to all local pilots and the FAA will give notice to all U.S. pilots three days out. Pilots will see the notification when they file their flight plans.

Salisbury said pilots can use the airports at Gig Harbor, Auburn and Renton, along with the Tacoma Narrows Field. Larger jets may have to use Boeing Field in Seattle. A short runway next to the terminal will remain open so helicopters can continue to land.

On average, the airport sees 100 to 150 take-offs and landings on a busy day, Salisbury said. Much of that depends on the weather because there is no control tower.

He thinks the 36-hour closer is workable for area pilots. The last time the runway closed was in 2009 for resurfacing.

“They’re actually excited about the fact that the designation is happening,” he said. “It’s also been an educational process for those who don’t fly – learning about the shifts in true north.”

If it does rain, the project will have to be rescheduled, he said.

“We’ll work with the FAA and the contractor and look at what will work for all of us,” he said.

The general contractor on the project is Strip Rite, which has a location at the port’s neighboring industrial park.

For more information, checkout www.portofbremerton.org.