> 20+ minute flights That's 10 minutes each way. Assuming they fly at 30 mph, you get a range of 5 miles. That might work for big cities, assuming they can fly

> 20+ minute flights That's 10 minutes each way. Assuming they fly at 30 mph, you get a range of 5 miles. That might work for big cities, assuming they can fly for 5 miles in a straight line, which they can't. > No, GPS is perfectly reliable "at best", and utterly nonfunctional at worst. Fortunately, there are lots of alternatives for GPS. GPS got hacked a long time ago, and even military drones got stolen using a fake GPS transmission. There are not that many GPS alternatives. GLONASS. Maybe if you have some local towers, but that's a huge project in itself.