Amazon Delivers Some Pie in the Sky – NYTimes.com.

I’m not impressed by Google’s “aerial delivery.” It’s easy to demonstrate a show system. But it will be very hard to create a safe system that can deliver loads of a few pounds, at a distance of even a few miles, much less the 10 that Jeff Bezos apparently claimed. Or to deliver to a specific person in an apartment building.

Here’s a quick response I wrote on Andrew McAfee’s page about this.

I’m skeptical. There are real safety issues here, as well as weight/payload/power issues. To deliver a 2kg package 30 km will take a vehicle gross weight > 6 kg (rough numbers). And helicopters, unlike fixed wing,  are “fail-dangerous.” Not to mention problems of delivering to a specific person in an urban environment. So I call “pie-in-the-sky” on this.

I see others are being skeptical because of regulatory problems. Yet other countries are way ahead of U.S. on regulation, and I don’t think regulation is the fundamental problem. The real problems include safety and payload:

• Helicopters (actually, multirotors) have very limited endurance and therefore range. You can put a big battery on them, but then you need a bigger machine to carry the weight.
• They have limited payload. Four ounces is no problem; but 5 pounds requires, right now, a machine with a total span of about three feet.
• At least six motors and props will be needed (called a hexacopter). Otherwise, failure of a single engine would cause an immediate crash. Even with six or more rotors, a total power failure, or a guidance  failure, causes a crash. In a crash, the operator has  zero control on where the machine ends up. This is unlike an aircraft.
• A machine this size that crashes is big enough to kill someone underneath. Especially if some of the motors are still operating. Even professionals are very careful about what they fly over. You can see videos on Youtube of idiots flying over crowded beaches, but a few people have been badly hurt this way, and the number will grow.
• Navigation using programmed routes is straightforward in clear areas, by using GPS-based-autopilots. But with obstacles (trees, buildings) a lot of development work remains. This problem, unlike the others, will be solved eventually by Moore’s Law.
• If you use an aircraft (wings) instead of a copter, many of the safety issues get much better. But on the other hand, you need a much larger area to land in. You can’t land in someone’s back yard.

Most of these problems are due to laws of physics, not the capability of current electronics. In short, delivering packages is an active area of R&D, but it will be feasible only in  situations where it is almost useless:

• When you will be flying in unpopulated areas
• When you can afford to crash, and lose, a few percent of your vehicles.
• When the load is small, and the range is short.

There may be  some cases that fit this description, but very few. For the next 5+ years, using drones for that don’t have to land remotely – mainly for remote sensing – is going to be the only practical application. Unless you have a military budget, of course.