STATE OF THE ART -- Part 3 -- "Wild Cards"
YOU MIGHT BE SURPRISED! : At least two of the above entrants have real potential. We're not betting against any one of them. (If not to populate the driveways of the nation, then at least to carve out a limited niche market). The Meluki winged VTOL flyer at far left has a control system that is (not surprisingly) comlex and proving difficult to perfect; if successful it will naturally be the preserve of pilots who are highly experienced with VTOL aircraft. Given enough altitude, it can enter into a glide--but it has no capacity for a straight-down 'parachute' landing, which is what is wanted in any hovering recreational vehicle.
Second from left: No solution has yet been suggested, but you can just bet that the daredevils who 'slope-soar' in these flying suits are keeping themselves awake at night trying to think of ways to accomplish the entire VTOL program without having to jump out of a plane.
Third and 6th from left. Mini-dirigibles are a slam-dunk in our opinion--especially with the advent of gas-impervious films, light, powerful engines, and so on. The variable-geometry lifting bag/wing model (2nd from right) is an especially clever design for those with a very small backyard. Training requirements and difficulty of operation are on a par with that of an average ultralight--well within the capability of the occassional, recreational user. Could well become the Lift-Jets' number-one competitor.
Fourth from left, Ornithopters: This is the wild card in the pack. The first to be imagined and the very last aircraft type to come to fruition, my bet is that hang-glider sized ornithopters with a powered, foot-launch capability will be here within 5 years. With motorized and man-powered orni-birds having both been successfully flown, launch-assist ornithopter/gliders--possibly electrically-powered--should soon follow. However, they won't look anything like a conventional hang glider or like the ultralight configuration shown above, but will have prone pilot in a more vertical aspect, with a bat-like or insectile appearance.
Speaking of insectile, how about the candidate on the far right: ? Far out! This unusual prospect has just made its appearance and I'm not sure what to make of it yet. It appears to have a variable-geometry wing and, given its stance, We wouldn't be surprised if it was capable of a hover using those wings to deflect thrust. Really clever, if it works (But oh.... do we have to keep saying it? No backup descent system for when the motor runs out of gas!)
Ditto for the other winged VTOL.. fifth from the left; This is one more example of the numerous tilt-wings and tilt-rotors that are being seriously put forward as candidates for the Backyard Flyer. Its just not going to happen. Just ask any of the pilots of the Army's "Osprey" tilt-rotor if they think this type of aircraft will ever be suitable for the casual recreational user. Its actually more difficult to fly than a conventional helicopter-which is saying a lot!
Jarno Smoot Hoax: A dutch CG specialist produced a very believable vid of a homemade ornithopter taking-off from a city park and flying at about 100 foot alt. It went viral even though totally bogus. The interesting thing about Smoots' work is that in the on-line discussion that followed, a lot of aero-experts and glider pilots weighed-in with the opinion that his completely fabricated design probably would work, given good quality materials and components. In fact we're half-expecting someone to reproduce this feat--but for real this time--any month now. The Snowbird man-powered ornithopter has already flown, and that with only about 1/4 to 1/2 horsepower. I would expect a foot-launched ornithopter to have less span than those which have gone before, enabling it to hover and take-off and land vertically. Some sort of compound wing might efficiently convert rapid wing-tip oscillations without giving up the strength & span needed for a good gliding wing.
SMALL HELICOPTERS--THE ONLY Backyard Fliers WORTHY OF THE NAME (And Still a Long Way From Ideal):
Its no wonder that sales of conventional small helicopters have been on the rise; just look what these diminuitive machines can do...First, its SAFE! the rotor is fully autorotatable, giving the heli a gentle glide slope, from any alititude, whenever there is a loss of power. Vertical take-off and landing and a relatively small rotor diameter (22-32 feet) means it can get into some pretty small spaces. Several reliable manufacturers now produce them. Third and 4th from the left show 'Angel' and 'Mosquito' type kits-builds. The Mosquito costs about $35,000, with a hundred-hour build time, and the basic model can be classed under the ultralight category which requires no certification or pilots license in the United States. Accessories such as amphibious floats, or canopies, or the 2-seat version puts it over the ultralight weight limit which does require a license and certification. Although it doesn't have the capacity for a lot of cargo, it can get one into the outback in short order, with a top speed of 80 mph, and a range of 150 miles. The main drawback of the Mosquito and its imitators is that, being a conventional design having a tail-rotor, (and an open main rotor--which always makes us nervous) there is a fair amount of hand-eye co-ordination involved, which takes a lot of very expensive training. Its the type of skill which must be kept honed too, with monthly refreshers, at least; Therfor it requires a serious commitment, not just in money, but in your time as well. For these reasons, it just misses being the ideal Personal Flying Vehicle.
The level of difficulty in operating a conventional helicopters is what has always provided the impetus to develop an easier-to-fly weight-shift rotorcraft. Its the reason so many attempts have been made to develop an easy-to-fly torqueless rotor--of which the coaxial rotor is just one. As we've seen over and over, however, the coxial system, involving small-span rotors, are not amenable to autorotation, making them unsafe and unfit for our popular flyer.
One platform-type coaxial rotor, the US Army Aerocycle, did promise autorotation by making the longer blades flex in a specific way. Unfortunately it worked imperfectly and was not developed further. That's too bad, because as we've seen, the simplicity of operation and intuitive control of the platform types is exactly what we want for our casual, recreational puddle-jumper.
The good news is that co-axial rotors are not the ONLY torqueless rotor available. Jet-tip models, such as the Hiller Hornet (2nd from right) and the Gluharef MEG-3 (far right) were flown very successfully, but consumers objected to the screaching whine of the pulse jets. The jets also got hot enough to become a fire hazard upon landing. Other torquless rotors have been tried, using small gas engines driving propellers mounted on the blades, and they also have been made to work since these kinds of self-propelled rotors are very easily made autorotatable, It is curious that the concept hasn't been taken further. Glenn Leavers' Portfolio includes one such design, probably having patent-potential. It is currently mothballed--at least until the "Lift-Jet" prototype is flying successfully.