With 11,000 flights notched up, California start-up Zipline’s work with drones in Africa could prove to be a blueprint for future autonomous transport and logistics systems around the world.
UAVs grab headlines as a nuisance or a growing threat to aircraft but there are other scenarios in which useful drones are well integrated into controlled air space.
This is what’s happened in Rwanda, and now Ghana, in Africa.
“Here we have established the biggest logistics system operated by autonomous drones on the planet,” Zipline’s founder and chief engineer Keenan Wyrobek told AirlineRatings in a recent interview.
“We have just achieved over one million flight kilometres in over 11,000 flights, every week our flights equal one circle around the globe, each day we fly up to 60 times with 16 drones.”
Those were the figures for Rwanda before operations started in Ghana in late April on an even bigger scale.
Rwanda served as a perfect testing ground – especially in how to integrate a drone logistics system with air traffic control — as it pursued its objective to save thousands of lives around the country.
This apparently worked so well that air traffic control in Kigali airport, Rwanda’s capital, pitched the system to their colleagues in Ghana.
The small country of Rwanda, less than half the size of Tasmania, has established itself as a driver of innovation, so much so that even auto giants like Volkswagen use it as testing grounds for new mobility concepts.
The Californians have set up the first, and so far only, nationwide drone delivery system in Rwanda, enabling the provision of emergency health care for 11 million people even in remote regions.
Within a few minutes, these Rwandans now have access to lifesaving donor blood or other essential medical supplies.
Zipline is especially proud that there never has been a single accident.
“Prior to starting operations we have done over 10,000 test flights on our grounds in California and substantially refined the drones,” explains Wyrobek.
Redundancy is of utmost importance in Zipline’s drone design, boasting both double sets of propellers and electric motors, as well as an emergency parachute.
“We haven’t experienced any bird strikes as of yet, for which Africa is notorious,” Wyrobek adds. “Our drones are slow, only half as fast as a Cessna, and so are predictable enough for birds.”
The company opened a similar system in Ghana in late April and multiplied its reach.
It now stands at 22 million people covered, with two distribution centers in Rwanda and three in Ghana.
Within a year, Zipline claims it will be able to serve 100 million people with new projects coming up in South East Asia and also in the US.
The first project in Zipline’s home country will be a quantum leap and is set to be based in North Carolina in the next few months.
Flying drones is comparatively simple in less densely populated African countries with significantly less commercial air traffic.
The big challenge in the US will be how to integrate drones operating autonomously into controlled air space and how to guarantee that they neither endanger people and property on the ground nor other aircraft.
Only if this can be solved in a convincing manner will drones have a chance to usefully complement existing logistical chains in industrial nations.
For Zipline, North Carolina is a pilot project to come up with practical rules and validate these in collaboration with the US Federal Aviation Administration.
For this purpose, the FAA has started the Unmanned Aircraft Systems Integration Pilot Program. Already today one can see how this can work in everyday operations in Rwanda, if on a much smaller scale.
Speed is most essential and therefore simple procedures. The drones have been developed in-house, resembling small aircraft more than quadrocopters which are much more widely known as drones. But these mini helicopters would be too slow and consume too much energy, while they also lack the necessary range.
The Zipline drones, in contrast, measure 2.25 meters in length, boast a wingspan of 3.30 meter, weigh up to 21 kilos and are able to carry a maximum of 1.75 kilos in payload.
The fuselage structure consists of high-strength composite material, while the outer surface is made of Styrofoam and thus easy to replace.
The horizontal stabilizers and wing structures are 3D-printed, the wings are attached to the fuselage manually and ground crew inspects them before take-off by a smartphone app and QR codes.
The heaviest part is the lithium-ion battery pack weighing ten kilos, it also contains the continuously running GPS unit supplying input about route and destination. The batteries have an output of 1.25 kWh, enabling the drone to fly up to two hours.
Take-off is from a ramp where the aircraft sits on a sled accelerated by an electric motor in just 0.3 seconds to cruise speed of 101 km/h, while the maximum speed is 128 km/h.
The drones follow the terrain keeping an altitude of 100 meters above ground, they can be operated safely in any weather 24/7 within a radius of 80 km from their base.
Arriving at the designated hospital, they release their cargo and the red cardboard box smoothly glides to the ground with its paper parachute. Such a delivery currently costs $US23 in Rwanda and reportedly less in Ghana.
Then the aircraft starts the return journey.
The landing is spectacular: Similar to Navy fighter jets on an aircraft carrier, the drone is equipped with a hook under its tail. GPS and radio sensors navigate it precisely into a cable running between two poles.
The cable catches the drone and brings it smoothly to the ground, leaving it dangling like a child on a swing.
In 10 percent of cases, the mechanism fails on the first attempt, initiating an automatic go around.
And just in case, Rwandan President Paul Kagame has insisted on the inclusion of an emergency button, enabling operators to call all drones back to base at once.