Karl, Was that in a Europa? I do not want to rabbit on endlessly but my
own plan had been also to link the engine frame to the tail spring of my
mono in case the lightning came at me in that direction, Regards, David
On 2014-11-14 14:53, Karl Heindl wrote:
> DAVID,
>
> THERE ARE ALWAYS EXCEPTIONS. WHEN I WAS HIT BY LIGHTNING, OR CALL IT
> ELECTRICAL
DISCHARGE, IN CLEAR SKIES, IT ENTERED VIA THE TAILPIPE AND EXITED VIA THE
RADIATORS.
APART FROM SOME MELTED METAL THERE WAS NO DAMAGE. I ALSO HAVE NAV LIGHTS
ON THE WING TIPS.
> IT JUST ILLUSTRATES THAT JUST STAYING AWAY FROM CU NIMS IS NO GUARANTEE FOR
> AVOIDING
A STRIKE.
> Karl
>
> -------------------------
> Date: Fri, 14 Nov 2014 10:49:26 +0000
> From: davidjoyce@doctors.org.uk
> To: europa-list@matronics.com
> Subject: Re: Europa-List: Re: Electrical bonding
>
> John & Ira , With the greatest of respect for your professional electrical &
aeroengineering backgrounds, I think there are two rather different issues here:
> For certified commercial aircraft lightning protection standards seek to
> enclose
all passengers and key aircraft components in a Faraday cage conducting system
that will cope with the fairly frequent strikes affecting commercial operations
without any significant damage. To bring composite aircraft to that standard
clearly involves incorporating some conducting material in the entire surface
of the plane and this is a nonstarter (or at least a non retrospective mod
option) for a plane like ours.
> The other issue is the possibility of minimising any damage to a plane like
> ours in the event of a lightning strike, ( absolutely going along with the
> assertion that it is much preferable to avoid it). There are three good
> accounts of fibreglass small aircraft strikes that I have come across and in
> every case lightning went from wingtip to wing tip causing significant
> damage. These cases are the UK glider, previously mentioned
> (www.aaib.gov.uk/cms_resources/dft_avsafety_pdf_500699.pdf [10] ) , another
> glider referred to in that AAIB report of the first glider and the Europa
> strike suffered by Paul McAlister
> (www.sarangan.org/europa_forum/2004-08/msg00094.html [11] ). In each case the
> pilot thought he was well clear of threatening clouds it seems. The gliders
> had the strike track along the aileron control rods whereas with the Europa
> it tracked along the wing tip lights wiring killing a number of the avionics
> in passing. I would strongly recommend folk reading all these repo
rts.
Having personally done so I cannot avoid the conclusions that :
> 1. Getting struck by lightning is a real possibility for any sensible,
> cautious
pilot let alone someone contemplating flying through the ITCZ where rapidly
developing massive Cu Nims are endemic
> 2. Lightning can and will pass from wingtip to wing tip along the most
> available
conducting track
> 3. More debateable perhaps but my third conclusion was that there is much to
be said for offering a track that steers clear of vital structures, and in the
light of this I had (in 2006) planned laying expanded aluminium mesh in the wing
close outs connected to aluminium foil over the wing tip and to the rear lift
pins/connecting rod. Nowadays I would no doubt use Aluminium Microgrid
obtainable
at modest cost from Aircraft Spruce. I would not for a moment want to
suggest that this would give commercial plane standard immunity to damage, but
that it would improve the chances of avoiding either the wing exploding or the
loss of avionics or other key electrical systems. I had toyed with the idea
of static diffusers but without a system of conducting static from other parts
of the aircraft I was not convinced this was workable ( and I guess that this
non conductance of static is what saves us from sparking when we touch ground
- we are only discharging the immediate area of cont
act.
> Regards, David Joyce, G-XSDJ
>
> On 2014-11-14 08:42, John Wighton wrote:
>
>>
>> Ira,
>>
>> You echo may own opinion on this subject. Fortunately my Europa does not seem
to generate a lot of static (of a kind that can be detected at least). There
is not a lot that could be done if it did collect static whilst airbourne.
>>
>> I had concerns about static build up and discharge on the ground,
>> particularly
whilst fuelling. I adopt the standard procedure of grounding everything to
the same potential by touch, relying on terra firma to act as a ground. So far
there has never been the hint of a discharge even after a vigorous polishing
session.
>>
>> Being involved in aircraft certification myself l am aware of the often heavy
and costly solutions on larger aircraft. I am a structures signatory on the
A350, this has a high level of composites content and poses new issues and
solutions
on many fronts, including bonding and lightning protection.
>>
>> --------
>> John Wighton
>> Europa XS trigear G-IPOD
>>
>> Read this topic online here:
>>
>> http://forums.matronics.com/viewtopic.php?p=433644#433644 [1]
>>
>> ectric.com
>> ">www.buildersbooks.com
>> builthelp.com
>> lotstore.com
>> m
>> .matronics.com/contribution
>> ttp://www.matronics.com/Navigator?Europa-List
>> ics.com
>
> ==========
> _blank">www.aeroelectric.com
> " target="_blank">www.buildersbooks.com
> ="_blank">www.homebuilthelp.com
> ="_blank">www.mypilotstore.com
> ank">www.mrrace.com
> ="_blank">http://www.matronics.com/contribution
> ==========
> target="_blank">http://www.matronics.com/Navigator?Europa-List
> ==========
> http://forums.matronics.com
> ==========
>
Links:
------
[1] http://forums.matronics.com/viewtopic.php?p=433644#433644
[2] http://www.aeroelectric.com
[3] http://www.buildersbooks.com
[4] http://www.homebuilthelp.com
[5] http://www.mypilotstore.com
[6] http://www.mrrace.com
[7] http://www.matronics.com/contribution
[8] http://www.matronics.com/Navigator?Europa-List
[9] http://forums.matronics.com
[10] http://www.aaib.gov.uk/cms_resources/dft_avsafety_pdf_500699.pdf
[11] http://www.sarangan.org/europa_forum/2004-08/msg00094.html
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