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FreeFlight
Aviation's Wildest Dream
...So pretty a sail it seemed
As if it could not be,
Some thought it a dream
Of sailing that beautiful sea---
Field; Wynkin, Bynkin, & Nod
FreeFlight is a fuel-less aviation of ultralight kite elements tethered across wind gradients, sailing in 3D as Wayne German put it. Kitesurfers are already close to endless hang-time, swinging as drogue pendulums under a big kites for minutes at a time. This curious physics violates common sense, true wind negated by apparent wind. Paragliders have shorter lines & swing less, so they don't see the effect as much. Instead they float on rising air- conventional soaring. FreeFlight is beyond soaring, but the two principles work together.
When a tall kite train breaks loose it skips huge distances buoyed up by a FreeFlight effect.
Notes:
A giant single-skin soft kite is proposed as the upper of a two kite system. A sweeping parafoil or LEI kite is proposed, perhaps augmented by a single skin soft kite in light conditions.
Much of the charm & utility of FreeFlight
Kites tethered across a vertical a wind gradient might have the lower kite sweep in a circle on a swivel, as sweep works best low in a kite's window, while the upper kite, high in its window, is poorly placed for sweep. So a huge light kite aloft & a hot spinning kite low & near the lower kite, a payload lander with generator/motor reeling function.
The stratospheric return flow from Low pressure to High crosses against the lower tropospheric flow (weather), a major wind differential for FreeFlight to aspire to.
FreeFlight will be reeling-intensive, high speed play-out & take-up being a basic control input. Modern airsport reels reach around 50 km/hr. in powered take-up. Unbraked play-out could be fatal.
Thermal soaring generally stops at sunset, but prevailing winds continue above above nighttime's surface inversion tendency. Thus FreeFlight opens up the night. Night air is colder/denser than day, which helps.
FreeFlight launch is downwind, at the surface, a wheeled carriage the most obvious approach, but water, snow/ice, & other mediums will work, as well as launch from terrain & even foot-launch.
Mini-jetstreams lurk in local windfields, if targeted yield power far above average values, similarly slack zones lag behind average & can be avoided. Convection tails are an elevator to the sky.
Touch & go landings will common in marginal winds. Semi-FreeFlight will be cool, rapid tether winching or simply teabagging will allow large controlled bounds over the surface, going right over obstacles
Excess payloads could be towed at the surface. A kitewagon is a base for conventional kite flight awaiting conditions to cut loose & fly the FreeFlight gear.
Mountaineering & industrial climbing techniques are ready for human FreeFlight use. The hardware is topnotch, proven.
A ~100 sq. m upper kite (opposed to a ~20 sq. m lower kite) would carry a human in many conditions. KiteShip's OL kite developed for 12m yacht racing would do.
HAPA concept (water-kite tethered to sky-kite) is a bridge to FreeFlight.
FreeFlight: The New Aviation
Soaring is based on vertical air motion. FreeFlight far extends soaring by tapping horizontal & gradient flow.
It was Wayne German who has most inspired work on FreeFlight. Wayne German's white paper- http://cache.zoominfo.com/cachedpage/?archive_id=0&page_id=763811573&page_url=%2f%2fwww.yellowairplane.com%2fMISC%2fTethered_Airfoils%2findex.htm&page_last_updated=9%2f6%2f2006+8%3a52%3a36+AM&firstName=Wayne&lastName=German
KiteLab ready for free flight demo in '09, when conditions right, don't want kites to fly out-to-sea or inland, need kill mech if demo is to be untethered to ground, start with a slack retriever-line.
KiteLab preparing RC experiments of "tacking in 3D', a new art (previous demos had no control but showed sustained flight), & keep hyping the idea to KiteShip to do a historic human flight with the giant kites already on hand. Some are leaning toward secret flights for capitalistic advantage, but this also suits the dramatic rumor scenario... free flight is the future of truly living in the sky.
Portland scale demos of kitepower (mechanical power down to a ground gen) & FreeFlight (sustained flight by two opposed kites across a wind gradient) with Wayne German, who has long championed such concepts.
Sustained flight without ground-tether, thermal, engine, or gasbag
Manlifting is the dated term for a simple way to live in the sky with mere kites; call it FolkLofting.
comment to: santos137@yahoo.com