Project Wing: Google’s Secret Program for Delivery Drones

The Atlantic reports that Google’s skunkworks Google X team has spent the last two years working on a secret program. More ambitious than the teaser Amazon pushed out earlier this year, Google appears to be serious about delivery in the air, getting products from the warehouse to their destination in about two minutes.
Alexis Madrigal has a very nice scoop about the secretive project. He reports that Google developed a special kind of unmanned arial vehicle called a "tail sitter" that’s specially designed for delivery.
A hybrid of a plane and a helicopter that takes off vertically, then rotates to a horizontal position for flying around. For delivery, it hovers and winches packages down to the ground. At the end of the tether, there’s a little bundle of electronics they call the "egg," which detects that the package has hit the ground, detaches from the delivery, and is pulled back up into the body of the vehicle.
That’s an impressive sounding design and if you head over to The Atlantic post and watch the embedded video, you actually get the sense that this could work. But can it work?