Solution to FAA-Required Tether Conspicuity
for Crosswind AWES
The FAA requires that a tether be
conspicuous the flying public by day or night. AOPA, EAA, and NAAA have
all lined up to demand this standard be enforced. Any AWES development
team unable to comply is unlikely to advance against this combined
Crosswind AWES seems rather disadvantaged, as the requirement entails
large FAA-orange-and-white banners and
marking FA-red lights of a minimum brightness every fifty feet of tether.
Virtually every crosswind team responding to the FAA question over AWES
conspicuity expressed a problem with either the added tether aerodrag or
how these devices will meet power-needs or cope with winching.
A KiteLab Group solution to the single-line crosswind case is sweeping
stacks of wings, an orange or white wing every 50 ft, with an embedded
RAT to drive the lighting. Required conspicuity thus becomes naturally
easy and even exceedable. A stack of wings generally develops far more
power than a single wing. Stacks have been long known in sport-kite
circles as a powerful standard configuration. The wings could stack and
unstack at the ground by gripping or releasing* (or hanking on and off)
the tether as it is extended or retracted from its winch.
Thus the aviation conspicuity "problem" is converted into a synergistic
* A trick common to legacy cable cars
~Dave Santos 7Eeb2012 AWES5594
Comment and development of this topic will be occurring here.
All, send notes, drawings, and photographs!
Terms and aspects:
Related links and concepts:
Commentary is welcome:
I see no problem with compliance to that visibility standard for a dense
stack of rotating rings.
As for the cable car type clamping... inspiration from that thought
I don't remember ever having considered using tether clamping radially
on the outside or inside edge of the ring bag. Doh
It has so many obvious advantages for rigging, launching and recovery.
And could in all probability, with enough gizmo, be done on a live
As for clamping on a line with COTS, sailing hardware is our obvious
expedient, there are plenty of cam cleats, clam cleats, clutches, and
jammers to choose from; the simplest light ABS plastic types are
particularly suitable and cheap. In combination with preventer stoppers,
shackles, and/or kite-killers, this is a very optimal method.
The current kiter's low tech method is to wrap the kiteline about eight
times around an Alu carabiner to attach junk, but this is hard to do
under tension. KiteLab Ilwaco has developed simple bent wire line
attachment hardware suited for small systems. These work and are more
handy and far cheaper than 'biners.
The Alpine Butterfly Knot is good for adding attachment loops on a line;
the high safety margin required for line nicks allows for the small loss
of breaking strength the knot introduces, (replace nicked or abraded
sections as they are found, as they act progressively; a quick fix is to
tie a Butterfly to isolate damage on the loop created).
KIS is King,
- Thanks, DaveS
Bunny ears is my favourite fun to tie and use knot ... must use it in my
A prussic or a rolling hitch could be used in a similar fashion..