Hoverbike Dreams versus Hoverbike Reality

The rules of the natural world are unbending, and when people try to bend nature to their desires, it's the people and not the rules that get bent. Physics dictate that to lift something, you need to exert a certain amount of force. The heavier the object being lifted, the more force you need. When it comes to what one might charitably call an "emerging" segment (the term implies that it's actually going to arrive at some point) of small multicopter and tiltrotor craft, weight is the enemy in more ways than one. For the plane to be both mildly crashworthy and to have a reasonable level of endurance, let's say 45 minutes of flying time, the craft would need to have fairly powerful motors with plenty of juice. Small ultralights with HUGE wings can fly reasonably well with 40 horses of power. For a mostly vehicle thing with no wings or tiny ones, that figure would need to be much greater, likely at least 100 horses. If it's not powered by an internal combustion engine, then that craft would need a lot of batteries, which are far, far heavier per unit of energy than a gas piston engine is. For hybrids, add up all the engines and motors and batteries and the weight penalty is staggering, which is a good word to describe how one of these things might fly, staggering into the sky.

For starters, for everyone to have a flying motorcycle in their garage, the mythical beast would have to be legal to fly. As far as the FAA is concerned, that means one of two things. The easiest and cheapest route for the manufacturer is to build what the FAA refers to as an ultralight vehicle---the FAA doesn't even use the term "aircraft" for them. Ultralights are largely unregulated. But there's a huge caveat. The max weight of a powered ultralight is 254 pounds. See section one, "Physics," to see the odds of hitting that weight. A Honda CB300, for reference, weighs around 350 pounds without wings or rotors and with just a tiny starting battery. Hitting 254 isn't impossible; at least one craft, the Jetson ONE, has done it. But because of the weight limitations, it can only fly for around 20 minutes before it becomes an anchor. The good part about the ultralight regs? One need not have any kind of license to fly an ultralight.

The allure of flying an airplane is that, to state the obvious, it goes into the air. Hovering? Not so much. The point of hovering eludes us. If you want to go very fast on or near the surface, get a motorcycle. They're cheap, legal and easy enough to ride. While hovering craft have long had an exotic appeal, in reality, almost no one wants to hover, nor should they. Very sensibly, they either want to drive or fly. Low-altitude forward motion in the cushion of the air is expensive and inefficient. Its main benefit is that crashing is less catastrophic. More on that in Part 6, Safety.

The other pathway for manufacturers to pursue, if they want to blow right past the 254-pound weight limit, is to get the craft approved by the FAA under one of a couple different regulatory frameworks, Part 23 or Light Sport Aircraft. The process for Part 23 certification is intensive and extremely expensive, costing tens if not hundreds of millions of dollars and many years to complete. Light Sport Aircraft is less heavily regulated. Manufacturers adhere to a set of industry consensus standards in building and designing the craft, and it's not an easy lift, just more doable than Part 23 approval. To operate a Light Sport Aircraft, a pilot needs to have just a valid driver's license, so pilot medical certification is not a huge hurdle, though pilots do need to go through extensive flight training and testing in order to get that Light Sport Pilot certificate.

Another pesky regulation has to do with airspace. To put it in context, the FAA's airspace restrictions are so complex that few active pilots understand them from top to bottom. They typically know the regs just well enough in most cases to avoid getting intercepted by fighter jets. An ultralight can only fly in unregulated airspace. And even though they are free to fly in what is known as Class G airspace, they still have to abide by the rules that mandate they stay at least 500 feet away from any person, vessel or structure. So a flying commute is, at least by today's rules, a nonstarter. In addition, what rules would apply to flying motorcyles? Road rules or flying rules? Or some hybrid of them?

How safe would a hoverbike be? Because of weight limitations, flying motorcycles would have little safety structure (though the safety cage of the 20-minute Jetson One is impressive). Hovering is probably about as safe as riding a motorcycle, which is to say, not very. And flying a fully certificated plane piloted by a fully certificated pilot is about as safe or unsafe as riding a motorcycle . Ultralight safety is largely unknown because of the unregulated nature of the activity, but it is likely many times less safe than flying a regulated small plane. And an important thing to remember is that once you get up to 100 feet off the ground or so, crashes are often catastrophic and fatal.

So, what are the odds that flying motorcycles will be filling the skies soon? Because of all these factors and more, there's close to zero chance for that kind of future. And that is not a bad thing. Not every fantasy has to be or should be acted upon.

Jetson One Selling like Swedish Hotcakes