Manchester's runway designation to change.

Apologies if this has been posted before but, just found this article on Manchester Airport's website.

Anyone know how often this happens? It seems like a really rare event to me!

[honey lamb]

See what happens when you stay away! We don't get these interesting little titbits

Actually, I wouldn't like to have to repaint the numbers on the start of the runway. Presumably, they'd have to do all 4 overnight?

[mcmbenjamin]

Happens (if at all) every ten to fifteen years. Because of magnetic field shifts