----- Original Message -----
From: "Martin Shaw" <jm.shaw@ntlworld.com>
Subject: Re: Europa-List: Re: Europa-List Digest: lightning strikes to
composite aircraft
|
| Paul,
| Points to remember about lightning strikes :-
| 1. Aircraft rubbing against the air generate an electric charge and this
| will attract a bolt of lightning from an oppositely charged Cb. Expensive
| aircraft have static discharge wicks to dissipate this charge
IMHO, not a point of interest. Our aircraft is too small to
build up any sort of large chargein time (it dissipates faster than it
forms). Also which charge counts - positive or negative? Who knows? Don't go
near them.
| 2. From personal experience I know that lightning can strike over 10 miles
| laterally out of a Cb.
The Atlantic North and Canadian maritimes are great generators
and have been struck dozens of times since 1948 DC3s to 767s. My minimum
personal distance is 25 miles at FRZLVL, 20 below. The thing is, where are
they without radar? Don't go near them.
|
| 3. A metal aeroplane is bonded together and so the electricity has the
full
| run of the whole aeroplane. You will, of course remember from your school
| days that like charges repel each other and so any electric charge, such
as
| a lightning strike will repel itself and stay in the outermost atoms of
the
| metal structure. You will therefore be safe unless wing-walking at the
time.
Very true. Unfortunately for us most of our 'outer atoms' are
inside the structure. Don't go near 'em.
| 4. A non conducting, plastic aeroplane struck by lightning will
disintegrate
| and the occupants will die.
... or in the case of the Brit glider, get burnt some.See:
http://www.dft.gov.uk/stellent/groups/dft_avsafety/documents/page/dft_avsafety_500699.hcsp
ALL ABOVE ON ONE LINE.
|
| See you in the bar on thundery days,| best wishes,| Martin Shaw.
Bang on, Martin! Don't go near 'em. They do what 8-foot gorillas
do - whatever they please. Reducing the electrical resistance to 12 volts
won't bother 100,000V at 60,000 amps.
Ferg
A064
|