REFLECTOR: Thunderstorms and composite airplanes

[KeithHallsten]

Below is a recent post to the AeroElectric List that seems applicable to
Velocity pilots as well.
Keith


Date:  8/04/2004
Time: 04:51:52 PM PST US
From: "Paul McAllister" <paul.mcallister at qia.net>
Subject: AeroElectric-List: Lighting strike

--> AeroElectric-List message posted by: "Paul McAllister"
<paul.mcallister at qia.net>

Hi all,

At the prompting of Eric Jones I thought I would share my experience
yesterday
of a lighting strike.  I published a similar note on the Europa forum.  For
those
unfamiliar it is composite construction.

I departed yesterday from KUES up to Canada.  About 90 minutes into the trip
I
took a lightning hit.  The weather was forecasted VFR clear, however about
70
minutes into the trip I began to suspect all was "not as advertised".  I
noticed
a cloud about 15 miles of my port side this looked ominous so I diverted
away
from it.  I was about to call flight service when suddenly I saw a bright
flash
on the tip off my starboard wing.  The starboard side was clear blue sky
and the port side was at least 10~15 miles from any clouds.  No obvious CB's
were
visible, however at 9000' it can be difficult to tell.

The main contactor dropped off line so things went pretty quiet until I
kicked
in the "E Buss" circuit. (Thanks Bob!!)

Damage is as follows:
- The paint is blistered on the starboard wing tip and the port side is only
blackened.
- The wing tip lights (Eric's design) are destroyed with some of the screws
melted.
- My Narco 122 VOR/LOC/GS is destroyed
- Wing leveler is destroyed
- Electronic fuel gauge.  This is a microprocessor based device.
- Main battery contactor (Kilovac EV200 AAANA) , which has an electronic
power
conservation circuit.
- Manifold pressure sensing input to the EIS engine monitor.

The Apollo GX 60 GPS/NAV/Com and transponder survived along with the EIS and
electronic propeller controller. Internal inspection of the wing tips
revealed no
sign of burning and nothing was evident when I removed the instrument panel,
or rear bulk heads. There appears to be no structural damage to the aircraft
or welding of the control elements.  It appeared that  the lighting entered
the
starboard wing tip, traveled along the common ground between the LED wing
tip
lights and exited the port wing tip.

Lessons learned?  Well it's hard to say.  I called for a standard briefing
90 minutes
before take off and was told "clear VFR, a nice afternoon to go flying".
I called Flight Service an hour after the event and they told me that the
convective
activity that subsequently moved through was completely unexpected.
I normally always file IFR, I think if I had done so this time I might have
been
warned.  I also think that I should have acted sooner on my hunch, a call 10
minutes sooner might have saved me a whole bunch of grief. Given that the
conduction
path was via the wing tip light ground I would probably increase the
wire size to 14 gauge and do something similar for the conductive path down
the
back of the aircraft.  Bottom line, stay a long, long way from black looking
clouds;
20 miles isn't enough in a tempting target like a composite aircraft.

Paul