Navigation markings on the ground, N. Africa
Hi all.
Over the years I've seen just a couple of references (with scant details) about navigation markings being laid out along the ground on long routes in northern Africa in the early days of aviation there, pre-radio navigation.
One suggestion I've seen is that there was an entire, unbroken line marked out on the ground along a route (I can't recall which one) of some hundreds of miles by digging a trench or some such. And perhaps large arrows or mounds as well.
Does this sound right? Does anyone have any details?
Thanks in advance.