Hi Guys
I sobering pic of lightning damage to a fully bonded all metal aeroplane
- I suspect in a Europa it would ruin your whole day!
Plus an interesting Boeing article.
http://www.boeing.com/commercial/aeromagazine/articles/2012_q4/4/
Regards
Pete
G-RMAC #109
On 12/11/14 17:24, davidjoyce@doctors.org.uk wrote:
>
> Peter, Thanks - absolutely no apologies needed - it is very
> pertinent! I had pored over this in great detail when preparing my Oz
> trip! Both in this and in the other GRP glider strike quoted the
> lightning ran from wing tip to wing tip, with arcing causing enough
> heating/shock wave to break open or delaminate the wing. It was very
> much because of this report that I hoped to provide a more attractive
> (both to me and the lightning) path running essentially outside the
> wing. Regards, David
>
> On 2014-11-12 16:07, PETER MORGANS wrote:
>
>> Hi David,
>> Apologies for diving in on this topic.
>> You may be interested to read AAIB Bulletin 12/99 (attached pdf)
>> regarding the disintegration of 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 category to have electrical
>> bonding. I think the answer is to stay away from large Cu unless you
>> have a parachute.
>> The following link, ref. this accident, also shows photographs of
>> damage:- www.pas.rochester.edu/~cline/.../ASK%20accident%20report.htm
>> It's sobering to look at the damage to fittings.
>> Regards
>> Peter Morgans G-CFKZ Trigear XS
>> ------------------------------------------------------------------------
>> *From:* "davidjoyce@doctors.org.uk" <davidjoyce@doctors.org.uk>
>> *To:* europa-list@matronics.com
>> *Sent:* Wednesday, 12 November 2014, 14:00
>> *Subject:* Re: Europa-List: Re: Electrical bonding
>>
>> Ira, You may well be right and I am quite prepared to accept your
>> superior electrical training, but talking to British Aerospce
>> engineers involved in lightning protection for the Airbus series did
>> not produce clear answers and my memory of the Europa lightning
>> strike account is that there were burn marks at each wing tip and the
>> strike had travelled across the 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. Having been in a tram
>> struck by lightning in my youth and lost a neighbour to a lightning
>> strike, I am not at all keen to go anywhere near a cu nim, but a
>> large proportion of those flying 'VMC' from UK to Australia have been
>> unintentionally 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.
>> Regards, David G-XSDJ
>> On 2014-11-12 13:17, rampil wrote:
>>
>>
>> Bonding together small bits of metal inside a sea of plastic insulator
>> will
>> accomplish nothing except add weight to your airframe unless you
>> have an array of static discharge wicks. No Europas I am aware off have
>> them. The best thing for a builder to do regarding lightning strikes
>> is to make sure there are no voids in the layups where water can
>> infiltrate.
>> The water will turn to steam and explode. Aside from that, Do not
>> fly near Cu. If Cu are unavoidable, just remember: Flying IS avoidable.
>> In 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 wingtip to
>> wingtip, etc. The goal can not be to conduct a strike - you can not!
>> Rather,
>> the goal of bonding to discharge wicks is to bleed off areas of air
>> friction
>> static charge back to the atmosphere, thus avoiding being an attractive
>> nuisance for lightning.
>>
>> There is no such this as "earth" on a composite airplane. The only
>> ground
>> is the negative battery terminal. That's it.
>>
>> It's not a house! There's no neutral (white wire) and earth ground (green
>> wire) dichotomy. Just make all grounds short, fat and tight.
>>
>> --------
>> Ira N224XS
>>
>>
>>
>>
>> Read this topic online here:
>>
>> http://forums.matronics.com/viewtopic.php?p=433500#433500
>>
>>
>>
>>
>>
>>
>>
>> ectric.com
>> ">www.buildersbooks.com
>> builthelp.com
>> lotstore.com
>> m
>> .matronics.com/contribution
>> ttp://www.matronics.com/Navigator?Europa-List
>> ics.com
>>
>>
>>
>> *www.aeroearget="_blank"
>> href="http://www.buildersbooks.com/";>www.buildersbooks.c* My Pilot
>> Storewww.mrr -->
>> <http://www.m%20rel=>http://www.matronics.com/Navigator?Europa-List
>> <http://www.matronics.gt;%20%3Ca%20rel=>=========
>>
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