I had the great idea of putting felt on the glare shield of my LS-3 to
hold down reflections. After burning a couple holes in it, I removed it.



Mark Zivley wrote:

I melted the aft facing edge of the GPS antenna that was mounted on the
shroud that covered the instrument panel on my LS-1F. I think it's not
the light passing through the canopy, but reflecting off the inside
surface when the open canopy is facing the sun. My glider was tail
pointed to the east and this was in the morning sun. Fortunately the
design of the LS-1 is such that it's unlikely that anything would find
it's way into the focal point of the beam in most cases.

Bob C wrote:

Yesterday afternoon Mark Mocho (MM Fabrication) opened
the canopy of his Pegasus to get his cell phone. By
the time he made a call to me, his soaring hat, which
was lying atop the glare shield, was smoking. The
canopy was acting like a big magnifying glass and focusing
the sun's rays onto a quarter-size spot just above
the instrument panel. Scary to think what would have
happened if he'd walked away for a few minutes.

Photos are at http://www.silentwingsairshows.com/canopy.html
Notice the burn marks on the instrument panel from
previous solar encounters. One shot is of Mark (no
that's NOT Jack Nicholson) duplicating the sun angle
with a flashlight.

I'd heard of this phenomenon before, but couldn't figure
out exactly how it happened. Seems it's not the light
coming through the canopy, but the light reflected
from the inner surface (which is roughly parabolic
in shape), that causes the problem. At a shallow grazing
angle, enough light is reflected to get smokin' hot.
Nice trick to know if you ever get ants in your cockpit
;o)

Bob