Dialling friends,
Like many of you, I have seen the signalling mirros with holes in the
centre etc. I have never used one, but I have a mirror successfully
to call in helicopters.
During field work in Antarctica, we didn't have radios, so we
made up some signalling mirrors. Just a rectangular piece of mirror
about 35 X 50 mm glued onto a lump of three-ply plywood. Sand off the
sharp edges, and voila.
The arangement was that were would be dropped off by helo, and the
wander around doing our field work, and be picked up somewhere in the
general vicinity. The pilot of the helo would approach our area of
work with the sun more or less behind him, and we could flash him
with the mirror really easily. Aiming was no great problem. Just hold
the mirror in one hand, and hold up the other with fingertips just
below the helo and in line with it. Gently twist the mirror so that
the sun's reflection moves up off the fingertip and zap's the pilot's
eyes. Dead easy when the helo is between you and the sun.
One rather hazy day, I flashed a pilot just to see if it workd. The
angle between the helo and the sun was about 120 degrees. One flash
and he made an abrupt turn and landed beside a rather embarrassed
John! No more randomly flashing pilots!
Hope that throws some light on it all (groan, what a lousy pun!)
John
Dr John Pickard
Senior Lecturer, Environmental Planning
Graduate School of the Environment
Macquarie University, NSW 2109 Australia
Phone + 61 2 9850 7981 (work)
+ 61 2 9482 8647 (home)
Fax + 61 2 9850 7972 (work)
