Copyrighted 2002 - All Rights Reserved - JEFF MacINNIS

CUTTING OUT - MUSHING

  With special attention to Indian/Indian hybrid fighter kites, this installment reviews two related fighter performance glitches.   Although these two examples feature undesirable flight characteristics, neither of them is an indication of a poor kite, and both of them are easily remedied.

  From a height of 1' foot, drop a well worn bar of soap length ways into a filled bath tub.   The soap tracks straight until it breaks the water line.   Then it abruptly switches direction followed by a reduction in speed.   This demonstration exemplifies what happens to a fighter kite when it is "Cutting Out".   Like the bar of soap, the kite suddenly changes direction from a steady track and forward velocity is momentarily retarded - resulting in a loss of control.

  Cutting out is not a freak encounter with a performance barrier.   The fighter pilot will know in advance 'something' is not right.   The clincher is when an attempt is made to leave the power zone straight down wind.   This is when the symptom of cutting out becomes obvious. More later...

From a height of outstretched arms overhead, slam a full pot of steaming oat meal full force onto the hood of your car.   This example may be loosely defined as "Mushing", and is similarly indicative of loss of control.   (ah-humm) However.   Mushing can be described as fighter kite performance that sort of emulates static kite flight characteristics - with basic maneuvers being difficult to execute.   Forward speed is slow, forays out of the power zone are near impossible, and a single spin can take an unreasonable length of time and distance.

  The cause of cutting out and mushing stem from bow strength of the kite.   For cutting out to occur the kite is likely under powered.   i.e. The spring rate of the bow is too stiff for the present wind condition providing little dihedral variation with a tendency toward the 'flat'.   For mushing to occur the kite is likely over powered.   i.e The spring rate of the bow is too soft for the present wind condition providing little dihedral variation with a tendency toward the 'swept'.

  When the bow of a fighter kite is flat or swept, the effect is predictable.   Although fighter jockeys have different preferences with regard to performance, to one degree or another all of their kites will have one thing in common: Variable dihedral.   Meaning: Increments of dihedral between flat and full sweep; on and off.   With a kite well suited for wind conditions, the increments of dihedral should flow evenly, uninterrupted throughout total bow travel.   This is the heart and soul of what makes a fighter kite what it is.   Its what makes it go.

  The most simple remedy for cutting out and mushing is switching kites better suited for wind conditions.   Yer' kite is probably pretty good, just not right now.   Save the 'cut out' kite for a stronger wind, and the 'musher' for a lighter wind.   One fix I heard about was of a limp kite in a strong wind.   The clever pilot decided a reduction in sail area would turn the trick.   This on the spot alteration was executed by poking holes in the sail with a hot cigarette.

  For the prepared kite enthusiast, nothing beats a good arsenal.   If your preference of kite has a standard shape or proportion, start from a medium sized kite and build several like examples in 1/2 inch wide increments both larger and smaller.   This will provide a starting point, even when subtracting the predicable shape and sizes.   Other construction considerations are so varied they'll provide plenty of opportunity for adjustments and tinkering.

  FLY HAIRY!

  the fat kid