Drone technology is advancing even faster than anyone expected, and one of the latest trends is unmanned passenger-carrying vehicles. The ultimate aim of developers of these products seems to mirror the efforts of Google and car manufacturers to put driverless cars onto the roads. From a technological and ethical standpoint, driverless cars make a lot of sense; far fewer people would die in automobile crashes if properly programmed computers and not people were at the controls.
But I’m not so sure this translates into aerial vehicles.
Guangzhou, China-based drone manufacturer Ehang made a big splash at the Consumer Electronics show in January, unveiling the Ehang 184, a single-passenger sixcopter. The goal is a low-altitude autonomous transportation vehicle. The passenger would climb in, tell the Ehang 184 where to go then sit back and try to relax. The idea is compelling, and the Ehang video makes the concept look so realistic and achievable. At the end of the video, the narrator makes an emotionally appealing conclusion: “Ehang will always keep in mind its humble beginning, put our heart and soul with the products we build, absolute safety by design, automation and sync-flight management platform. You have our word. Once we begin, we will never give up.”
This is clearly a serious effort, and Ehang has been working on the 184 for a while.
There are plenty of other intriguing electrically powered human-carrying designs in the experimentation phase, many that look like multicopters on steroids with a human pilot sitting in the center of the action, or the Tactical Robotics AirMule, an industrial-looking autonomous payload carrier aimed at the air-ambulance market.
As super-neat as all these projects are, however, there is a fly in this ointment. None of these vehicles can be flown to a safe landing if they lose all power.
I figured this out the hard way, when my Yuneec Q500 lost power and crashed straight down from about 50 feet, into a sandy dry riverbed. There was a software problem that has since been fixed. But this accident made me realize that quadcopters can’t autorotate. When power is lost, they come down, and fast.
If these devices are going to carry passengers they either need to be equipped with a ballistic parachute, or they are going to have to meet incredibly stringent certification standards.
The latter could be more likely, because ballistic parachutes add weight and cost, although small lightweight chutes could easily be adapted to non-passenger-carrying drones.
So what about the certification standards? Basically, they would have to mirror fly-by-wire requirements. When designing a fly-by-wire system, engineers have to be able to prove that it meets the same reliability standards as a cable- or pushrod-driven system. This is a fairly huge mountain to climb, but when I’m flying in a fly-by-wire airplane, I sure am glad that this is the minimum standard that has to be met. And for darn sure, if I ever climb aboard an electric-drone-type vehicle, it had better meet the same standards or I’m not getting on board (unless I’m unconscious; then the AirMule can do whatever it wants with me).