Why We Renumber Runways When the Earth's Magnetic Field Shifts

The FAA can make the rules about air travel (god no inflight calls, please), but it's still beholden to the whims of earth's shifting magnetic field. Runways are named after their compass orientations to help pilots navigate. A changing magnetic field, however, means they now have to be renumbered. » 12/13/13 6:02pm 12/13/13 6:02pm