FairIP index

Advanced Kite Killing

AWE arrays must douse quickly & easily in an emergency. Prompt killing minimizes damage and risk in many failure-modes. Proposed FAA regulations require fast evasive action by a sUAS to give right-of-way to manned aircraft in shared airspace. A common kite problem is for wind to increase unexpectedly and overpower retraction force. Back-up landing methods are needed.

Kite killers for single traction kites are well known, but killers for arrays (trains and arches) hardly exist. Every lifter kite in an array might have its own killer as part of a hot-swap capability. Multiple killer tag-lines can be rigged as leaders along a main kill line whereby ongoing retraction of the mainline kills each kite in sequence. A parallel array of tag-lines can kill all kites at once, but considerable force is required. At some point a network of kill-lines becomes a nuisance. Distributed servo actuation becomes favored.

Another major kill method is "walking down" a kite. Compared to winching in a kite against the wind only a fraction of effort is needed to trolley downwind pulling the kiteline down until the kite is landed. A related method is for a kite vehicle to run downwind allowing its winch to more easily take in line. Similarly a dipping boom can be repeatedly tipped forward suddenly while winching to reduce the retraction force required. This is how a fishing rod is worked to bring in a fish more powerful than the reel by itself. These are options for the sort of fast evasive maneuver called for by proposed sUAS regulations.

Large soft kites can be killed by hand when they touch down. One runs up from downwind, just clear of the kite's scope, to wrestle down the fabric into a ball. Grabbing a kite by the tail is a sure way to "trip" it down. Pulling aft lines to windward, slacking windward lines, or pulling in one side all kill a kite.

An ancient method is to kill a kite with a kite by cutting its line with a knife or abrasive. A kite pilot may carry a hook-knife or for a huge hawser keep a machete, saw, or ax handy. Gomberg's quick-release for giant show kites simply releases the line. A cutaway kite drifts downwind landing some ~4x altitude, so it needs considerable space; and  there is a risk the cut tether can catch on obstacles or drag objects, extending flight. KiteLab's kite killers release a kite's side-bridle or fore-bridle line by a pin-release actuated by tag-line or remote/auto control. The kite comes right down and remains attached to its anchor.

FairIP/CoopIP                        ~~Dave Santos         May 19, 2010              M1542

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Terms and aspects:    stopping the flight of a kite system, side-bridle line, fore-bridle line, extending flight, kite killer, tag-line, walking down a kite, sUAS, small unmanned aerial systems, single traction kite system, AWE arrays, douse a kite system, runaway kite system, damage potential of runaway kite system, damage potential of an uncontrolled long lifted tether, kill a kite with a kite, failure, failure mode, tail, tripping a kite, right-of-way, regulations, retraction force, array-killing method, arch-killing method, train-killing method, multiple killer tag-lines, lifter kite, array's lifter kite, hot-swap capability, parallel array of tag-lines, kite's scope, sequential killing, distributed servo kite-killing systems, downwind-moving kiteline winching vehicle, LinKnife, soft kite, hard kite, kite wrestler, kite grabbers, kite catchers, cutaway kite, cutaway kite system, drift, aft lines, windward lines, dipping-boom AWECS, evasive maneuver, hand killing, kite pilot, hook knife, hawser, guillotine, machete, ax, saw, explosive cutter, cut tethers, pin-release, actuators, remote control of servos in kite-killing operations, kite capturing, kite retrieving,

Related links:


  • Aerial balling for quick dropping?
  • Aerial flagging for quick releasing of lift/drag?
  • Higher lifter kite system to capture killed kite system to avoid ground contacting of killed system?
  • Morphing kite sail body to glider at kill time, followed by GPS robotic gliding to port?
  • Disconnect tether at kite sail body if breakaway occurs; follow with morphing to robotic gliding to port.
  • Costs of killing kites?
  • Anticipating risks.