Drop, lower or land how do delivery drones deliver

The delivery drone industry has seemed to settle down to three ways of doing business, all of which do just what helicopters do but are smaller. Different ways that delivery drones work have advantages and disadvantages.

There are currently three favourites

Drop it and use a parachute to slow its descent. Zipline is the master of this method. My initial reaction to their plan was that it was madness. I have been proved very wrong.

The great advantage of this method is that you own the take-off and landing, by this I mean you know exactly what it looks like. 

Zipline use an overpowered launch rail to throw their airframes into the air, they fly their pre-planned route. A route that has been surveyed and well mapped by Zipline. Once it reaches its destination the Zip opens in effect bomb bay doors and drops the package which has its rate of descent checked by a small parachute. 

In many ways, this part is the only variable in the entire flight. If the drop zone is big enough it matters not if the person picking up the package has to walk an extra metre or two.

Zipline has a great deal of control over the end-to-end delivery.

Next up winching the parcel down Wing and Manna, and if fitted to their machines Wingcopter. After coming into the hover over the drop zone down on the end of a string comes the package. 

I am not so much of a fan of this method as it requires a great deal of power to be used whilst the package makes its way down the wire. If the winch fails you need to be able to cut the package away or be able to fly home and sort it out. It does avoid landing in an unknown unprepared site, this is how these companies deliver to homes.

Wingcopter is even capable of dropping multiple payloads.

Lastly land, either a conventionally configured airframe landing on a landing strip, not many folks are doing that. The popular way is to use a separate lift thrust airframe (SLT) a normal aircraft and a multirotor mashed together. Vertically pointing motors lift the craft into the sky and then horizontally mounted propellers fly it forward.

There is no need for a runway any large enough clear area will work. At the moment this is the most popular method by far. Many companies offer this sort of delivery. But you need complete control of the landing and take-off area. Making deliveries to homes impossible.