The personal jet pack invention never got very far. It could barely lift its own fuel, and so it had a range of zero useful miles.
The next step up are the helicopters we’ve had for for 60 years.
Why isn’t there something in between? A personal-size helicopter.
Like the jetpack, it would consist mainly of an engine and a harness, no big vehicle to lug around.
So, with a lot less weight to deal with, it would look like Inspector Gadget’s hat.
In other words, the question is why can’t helicopters get lighter and smaller instead of always larger and heavier?
You need a certain amount of wing area to generate lift. A smaller helicopter would need a larger rotor in proportion to its size to get airborn. A larger rotor needs a fairly large motor to turn it. Larger motors weight more, requiring more lifting surface. If you try to reduce the size of the rotor by turning it faster you run into structural problems, like chunks of the blades flying off at high speed.
It is more economical to build the larger helicopters.
And I for one would not trust you wallking about with a large rotating blade assembly just over your head. Tilt a little the wrong way and your tearing up divots all over the place and decapitating passersby.
There are personal sized helicopters and have been for many years. IIRC, as long as they are under 250lbs and can’t go faster than 60mph, they are exempt from FAA regs and considered experimental aircraft. The problem is not getting into the air as much as controlled flight. All kinds of secondary movements are induced by a spinning blade, the wind, etc. In order to just fly straight up and come back down, you need to counteract these secondary forces, with tail rotor blades, the right weight distribution, etc.
It is funny but if you look around you will find lots of plans for personal helicopters but not too many people actually claiming to be able to sell you a functional personal helicopter. I remember seeing these plans in Popular Science when I was a kid. I don’t know if that is due to Govt. regulations regarding exptl. aircraft or due to the fact that they really don’t work all that well
There is a reason that birds and insects have an upper functional limit on mass for hovering flight. Hovering is much more power-intensive than gliding/soaring/etc. As DrFidelius noted, more power requires a larger engine, which pushes your total mass up in a vicious cycle.
And the problem with manned helicopter flight is that you, the pilot, are just dead weight from a payload perspective. It is possible to make a light, cheap helicopter if you are willing to sacrifice payload - just look at all the radio-controlled helicopters available. As a point of reference, however, many of these require gyro-stabilization systems to make them flyable.
There are dozens of models of single seat helicopters available. I saw many of these models a few months ago at the Sun n Fun airshow in Lakeland. The problem I believe is that these are all classified in a way which means the owner must build the craft him/herself and therefore are sold in kit form. Most go for about $30k-50k and most don’t include an engine.
Why don’t aircraft manufacturers have a single seater for sale as a mass production model? My WAG guess is that for all the expense of getting safety certifications, they may as well sell models that a buyer can fly at least another person. They could never compete with the kit builts because they are so cheap. The low volume would just not be cost-effective. A typical 2-seater production helicopter (R22) costs around $200,000 plus roughly $80 an hour to operate. This is probably as low as you can get while still complying with strict FAA procedures reguations.
We’ve been hearing for years about the SoloTrek, which has not liven up to its promises so far of becoming a revolutionary method of transport. I don’t even know if the thing has sucessfully taken off yet.
On this site, the SoloTrek seems to still be around. They talk about military applications, but it seems to me that the thing is too noisy to be very stealthy, and I don’t think I’d want to be a GI flying in on one of those things into a combat zone. Too obvious a target.
It appears the TrekAero folks are also involved in making unmanned remote vehicles, which would seem to be the way the military is going rather than the James Bond jetpack route.
Here’s one that I heard about a while ago. I haven’t read through the site lately, but last I heard they expected to have these things for sale in the next year or so. The cost was expected to be about $50,000, which included flight training. Since the AirScooter classifies as an ultralight, it does not require a pilot’s license.
It’s hard to build a 3-axis fixed wing to conform with the Part 103 ultralight regs… for past 30 years no one has managed to do it at all for true helicopter. Won’t say it’s impossible, just that it hasn’t been done successfully, yet. Gyrocopters, yes, there are ultralight versions of those, but not of a helicopter.
It says on the AirScooter site that it can’t autorotate. This will be a problem if your engine ever quits.
[NitPick] They’re NOT exempt from FAA regs. They fall under Part 103 and not Part 91, but they’re still regulated, even if much less than most flying things.
Assuming they meet Part 103 requirements, they are not considered “experimental”, they’re “ultralights”. “Experimental” is a different thing under FAA rules, and governed by a different Parts of the regs. In fact, anything under Part 103 is not even considered an “aircraft” by the FAA, it’s an “air vehicle”.
And it’s under 254 lbs and under 63 mph. [/NitPick]
Selling them in kit form helps limit liability to the kit manufacturer. If you build 51% or more of an aircraft then YOU are considered the aircraft manufacturer and not the kit builder. I think not selling you the engine along with the kit might also work in the kit manufacturer’s favor if the matter ever winds up in court.
There are advantages to building from a kit. Cost is one. If you build it you can also make repairs on it without hiring a licensed mechanic (cost again). In which case you’re talking sweat equity here.
Aircraft build under the 51% homebuilt rule are all classified as “experimental” and must have that very word on the side of the machine where anyone getting inside can easily see it.
I’ve often wondered instead why there isn’t such a thing as a personal dirigible. How much helium would you need? It would seem that a hull 15 or 20 feet long would be pretty much adequate to support you. You’d only need a tiny engine. You wouldn’t get anywhere terribly fast, but it would be relatively safe. Except in a storm, of course.
Helium doesn’t have a huge amount of lift (1 m³ of helium will lift 1 kg). a 20 foot long blimp might be just enough to lift a person if they’re small and hanging from a rope, but not if you want it to have a gondola with a seat, engine, controls to steer, etc.
Here’s a single person pedal powered blimp called White Dwarf. It’s 48 feet long and holds 6200 cubic feet of helium. It’s very cool, and seems to work quite well. However, it’s not very practical if you want to use it to go places. It’s slow and would need to be flown in only very calm weather.
I’d assume it loses helium fairly quickly too. Helium atoms are small and leak out of a balloon faster than air does. Think of how by the next day a party balloon generally doesn’t have enough lift to keep itself in the air any more. You’d probably have to top off the blimp’s helium every few days, which would be pretty expensive.
It would be a lot of fun to have one just to screw around in, though. Some of those photos of White Dwarf in flight are spectacular.
This would be pretty much the same for helicopters; there are economies of scale to these things; large-ish helicopters work, as do large-ish VTOL jet aircraft (like the Harrier); small helicopters wouldn’t really work for the same reason that small VTOL jet aircraft (i.e. jet packs) don’t work - not all of the forces, effects and payoffs scale down proportionally.