Hi-David,=0AApologies for diving in on this topic.=0AYou may be intereste
d to read AAIB Bulletin 12/99 (attached pdf) regarding the disintegration o
f Schleicher ASK21 over Dunstable. Back in my gliding days in the late 1960
's it was mandatory for all gliders which held a B.G.A cloud flying categor
y to have electrical bonding. I think the answer is to stay away from large
Cu unless you have a parachute.=0AThe following link, ref. this accident,
also shows photographs of damage:- -www.pas.rochester.edu/~cline/.../ASK%
20accident%20report.htm=0AIt's sobering to look at the damage to fittings.
=0A=0ARegards=0APeter Morgans - - G-CFKZ - -Trigear XS=0A=0A=0A____
____________________________=0A From: "davidjoyce@doctors.org.uk" <davidjoy
ce@doctors.org.uk>=0ATo: europa-list@matronics.com =0ASent: Wednesday, 12 N
ovember 2014, 14:00=0ASubject: Re: Europa-List: Re: Electrical bonding=0A
=0A=0A=0A-=0AIra, You may well be right and I am quite prepared to accept
your superior electrical training, but talking to British Aerospce enginee
rs involved in lightning protection for the Airbus series did not produce c
lear answers and my memory of the Europa lightning strike account is that t
here were burn marks at each wing tip and the strike had travelled across t
he plane. That being the case, it seems to me to be a better idea to have a
path other than the aileron controls or wing light wiring to conduct it. H
aving been in a tram struck by lightning in my youth and lost a neighbour t
o a lightning strike, I am not at all keen to go anywhere near a cu nim, bu
t a large proportion of those flying 'VMC' from UK to Australia have been u
nintentionally caught in electrical storms. I did not imagine I could make
my plane immune to damage but just to lessen the likelihood of control run
welding or instrument burn out.=0ARegards, David G-XSDJ=0A-=0AOn 2014-11-
rampil@gmail.com> Bonding together small bits of metal inside a sea of plas
tic insulator will=0Aaccomplish nothing except add weight to your airframe
unless you =0Ahave an array of static discharge wicks. No Europas I am awar
e off have=0Athem. The best thing for a builder to do regarding lightning
strikes=0Ais to make sure there are no voids in the layups where water can
infiltrate.=0AThe water will turn to steam and explode. Aside from that, Do
not=0Afly near Cu. If Cu are unavoidable, just remember: Flying IS avoida
ble.=0AIn this I respectfully disagree with David. As a former electrical
engineer, I would also have to say, I can not see any benefit to bonding wi
ngtip to =0Awingtip, etc. The goal can not be to conduct a strike - you ca
n not! Rather, =0Athe goal of bonding to discharge wicks is to bleed off ar
eas of air friction =0Astatic charge back to the atmosphere, thus avoiding
being an attractive =0Anuisance for lightning. There is no such this as "ea
rth" on a composite airplane. The only ground=0Ais the negative battery te
rminal. That's it. It's not a house! There's no neutral (white wire) and e
arth ground (green=0Awire) dichotomy. Just make all grounds short, fat and
tight. --------=0AIra N224XS Read this topic online here: http://forums.ma
tronics.com/viewtopic.php?p=433500#433500 ectric.com=0A">www.buildersbook
s.com=0Abuilthelp.com=0Alotstore.com=0Am=0A.matronics.com/contribution=0Att
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