Posted: Sep 10, 2013 5:23 PM by Melissa Anderson - MTN News
Updated: Sep 10, 2013 5:32 PM
HELENA - A shift in the earth's magnetic polarity is costing the Helena Regional Airport $75,000.
The Federal Aviation Administration informed the airport manager nearly a year ago that navigation numbers listed on the runway need to be upgraded due to a slight shift in magnetic north.
Construction crews have been busy blasting off the old numbers, getting ready to paint the new ones.
One of the runways was closed down for a short time to make the changes.
Pilots use the numbers to navigate their flights for take-offs and landings.
Ron Mercer, Helena Regional Airport director, explained, "A pilot, if they are going to land on say runway 1-6, they know that the heading is 160 degrees. So when they are looking at their instrumentation, they want to be on heading for a 160 degree runway. And so just every so often, as that magnetic field changes, our runway headings get off one degree and they have to be redone."
Mercer says the last time they had to change the numbers due to polarity shifts was about eight years ago.
He says they are also incorporating other changes on the runway at this time, including a new lighting system and painting new center lines.