STATE OF THE ART --PART 2 - "The Old, The New, Flying Platforms & Scary Little Helicopters
AND THE NEW
FLYING PLATFORMS: (Or, "Oh no... we came so close!")
The thing about flying platforms that will forever make them unacceptable in the recreational market is their lack of a way to descend safely when the power goes out. (Notice I said, "when"). As mentioned in Pt.1, ballistic parachutes are ineffective at the low altitudes which are a personal flyers natural environment. The only other option is the not very practical, "don't fly higher than you want to fall." A second drawback of the platform is its inherent speed limitation; about 20 mph is the maximum horizontal speed its aerodynamics allow. These flaws are a travesty (especially the "fall like a stone" part) because the flying platorm is, otherwise, the best solution by far. Early on, NASA scientist C.H. Zimmerman and US Army engineers discovered that the platforms' particular "pilot-standing" geometry provided a kinesthetic, weight-shift method of control that was not only simpler than any other system, it was so nimble that the craft could be controlled, at altitude, in a stiff wind and hands-free (while shooting a rifle, in fact.) Several platforms easily met the Army specification that the vehicle must be capable of being mastered, by the "average G.I.", with 20 minutes of instruction or less. As well, the duct gives 30-40% more lift than an unducted rotor-making it the most efficient lifting device known.
CO-AXIAL ROTOR HELICOPTERS:
Coaxial rotor helicopters are a perennial favourite because, although not quite as responsive as the platforms, they are very easy to fly and intuitive to learn.. However, they also share the platforms Big Flaw--no ability to autorotate (glide safely to a landing when the motor quits) which unfortunately also eliminates this category as a contender to the recreational market. While the technical problems of getting a coaxial rotor to reliably autorotate are considerable, it isn't necessarily impossible. Aeromancer F.D. is one of a handful of companies that continues to pursue a solution--which won't come easily, or soon.
Doesn't meet our ultimate Personal Flyer criteria, but its what the public wants until the Vtol Personal Flyer comes along. Driven by the novice, recreational segment of the market, recent trends show that safe, forgiving handling tops the list of wants, evidenced by the number of Trikes, Flying-Wings, Box and Tandem Wings and the new, low & slow Displacement Wings (inflated wings that can be foot-launched just like the new electric hang-gliders). When this easy-to-fly, "stall-less" characteristic is combined with Stol, short & rough field, and amphibious capability--all of which increases the vehicles utility value--then you have a market-beater. There's every reason to believe that those are some of the same qualities that will be sought-for in our Personal Vtol Flyer. All of these types will be retained to become part of the futures' mix of recreational and 'local air-transport' fleet of vehicles.
GYROPLANES & JUMP--GYROS:
Juan de la Cierva's "autogyro" in its 10th decade of practical use, has not only proven itself, it has been constantly developed and improved, becoming a fast-growing category within the US homebuilt/kit-plane arena. When equipped with a prerotator, that spins up the rotor while the machine is stopped, then suddenly pitched-up, the gyro rises in a vertical jump, then begins its forward travel as the pusher-propeller imparts speed. Descents have always been able to be accomplished vertically (or, at least "near-vertically"). So with all that going for it, why don't we just call the gyro our favourite Personal Flyer and be done with it? The answer is that, even with the modern gyros' vertical landing and take-off, and its ability to get in and out of smaller fields than anything but a true helicopter, the fact that the gyro does not hover is a deal-breaker. It is the ability of our hoped-for Personal Flyer to hover that enables so much of what we need it to do. Maneuvering through a forest canopy or following the mountain trail, picking our way through a steep narrow valley, or canyon of hi-rises, or carefully setting down on some roof-top LZ (landing zone) are all capabilities expected from our flyer--and none of it is possible in a machine that must keep moving, at its own predetermined speed, to stay airborn. Another drawback of t he gyro is the open, spinning rotor, which creates a dangerous hazard on and near the ground (a serious concern it shares with every helicopter ever made.) Still, the easy-to-fly gyro will continue to have its place; there are some truly beautiful & practical gyros out there--check-out the roadable PAV (black machine, above). While not a fan of the "roadable aircraft" concept in general, the PAV is a work of art and a work of genius all at once, and I can't help but think that it will successfully carve out a place for itself in the increasingly crowded sky of the future.