According to what I've read, the main drawback to UAV mail delivery is how to ensure peoples safety. You don't necessarly want FedEX UAVs with sharp rotors landing on every door step....but what if the solution was not part of the UAV but part of your home. What if everyone had a chimney that was essentially just a mail chute and all the UAV did was land on your roof overnight and drop your package down the chute?...at least for packages under 5 lbs (which is most of the mail volume).-- ShawnBob, Dec 09 2013 This would be appropriate, given that most mail is used as kindling anyways.-- normzone, Dec 09 2013 We are wondering how much entertainment we might gain by Assimilating some of these little UAVs. Certainly, the Predators we have taken over are great fun ...-- 8th of 7, Dec 09 2013 "And then to top off a bad week, someone put a ferret and a wombat down my package chimbley..."-- popbottle, Dec 11 2013 At least the pear tree broke their fall, although the ferret has devoured the partridge …-- 8th of 7, Dec 11 2013 I figure the whole UAV mail thing is a farce. If we'd really wanted to do it, we could have done ballistic mail sending years ago. As long as the package stays within a certain weight and size, it could fit into into a pre-made, padded, heavy sabot that would be launched to your house. Then again I'm not sure if projectile calculations are actually accurate to within like 6 feet like they'd probably need to be if you don't want to damage anything accidentally-- EdwinBakery, Dec 12 2013 The calculations are accurate, but the outcome for large low-velocity projectiles is unpredictable. The circular error is high, increasing rapidly with increasing range.
This is because the projectile is not spin- stabilised, and will therefore "tumble"; since there wil almost certainly be a disparity between the centre of gravity and the volumetric centre, the flight path rapidly becomes chaotic.
Small variations in wind and air density also have a large influence.
For a 1m CEP, terminal guidance is essential.-- 8th of 7, Dec 12 2013 random, halfbakery