Wichita — The Wichita Eisenhower Nation airport will have to renumber its runways due to the slow but constant shift in the Earth’s magnetic poles that’s altered pilots’ compass headings.

Airport officials told members of the Wichita Airport Advisory Board this week that the compass headings of the airport’s three runways have shifted six degrees because of magnetic variation. The change has prompted the airport to plan to renumber its two primary and one crosswind runways for the first time in its nearly 64-year history, the Wichita Eagle reported.

Every five years, the Federal Aviation Administration tests magnetic variation and assigns the values that’ll be used in designating runways. A magnetic variation shift greater than 3 degrees prompts the administration to make changes to published airport approaches.

Wichita airport officials said the changes will likely cost the airport hundreds of thousands of dollars.

“Most of the physical costs would be airfield directional signage,” said Brad Christopher, assistant director of airports for the airport authority. “Almost all of those would have to be replaced.”