Mike,
I have also investigated underwater flash strobe units but their power
consumption appears to be excessive.
The battery operated strobes that I circulated last week are used on the
buoys of longline fishing lines operators and offer a reasonable battery
life, are only about $45 but are mainly for night use.
My unscientific (I am ignoring the double negative factor) thinking is a
that something bright and visible from ahead might increase visibility
somewhat and assist spotting intersecting courses from somewhere ahead.
Taking that Ventus/Skylark accident as an example, the report indicated that
the aircraft where both straight and level at least when they impacted, and
while it was at 28 degrees, a straight ahead light should have been visible
by one of the pilots .. but who knows what their heading and attitude was 10
seconds or more before.
One thing is clear and that is that it is impossible to find a simple (or
even a complicated) solution that will cover all eventualities ..........
but something like Flarm probably offers best potential if all pilots and
owners embrace it ... (what chance?).
From that French Report that Chris mentioned, it is clear that mid-airs
aren't their biggest problem ... although a death or 2 is still a problem.
Regards
Geoff
----- Original Message -----
From: "Mike Borgelt" <[EMAIL PROTECTED]>
To: "Discussion of issues relating to Soaring inAustralia."
<[email protected]>
Sent: Tuesday, July 12, 2005 10:23 AM
Subject: Re: Fw: [Aus-soaring] FLARM
At 10:05 AM 12/07/05 +1000, you wrote:
Thanks for that Bernard, & the visibility, before fitting it to
the ASW 28. That way I can return it in good condition and without
drilling holes, if the light isn't outstanding in bright daylight.
Does anyone in this forum know what work has been done with battery
operated strobes in front of a focusing reflector to provide best strobe
light in a defined direction? Best regards Geoff
Geoff,
I guess you could run some experiments with photo flash accessories to
try
the strobe/reflector thing.
Lights, particularly focussed forward strobes will help the head on
case(how narrow do you make the focus - the Ventus/Skylark 4 collision was
at 30deg from head on) but of course don't solve the mutual blind spot
problem and for those who believe we don't have a problem a friend of mine
who is an current Australian contest pilot has been to 3 contests where
pilots have died in mid airs and two more where mid airs occurred.
Mike
________
Also Adrian Jansen sent me this that he found the other day:
Mike,
Came across this for more than you ever wanted to know about photometry
of flashlights and visibility. Seems like its still an ongoing subject
for research.
http://cie2.nist.gov/meetings/1999_Warsaw/Workshop_Proceeding4.htm
Also some figures for light efficiency, all in lumens/watt:
Tungsten incandescent 12-20
Tungsten-halogen 18-25
Hi-efficiency fluorescent 45-60
White LED 25-60 ( best lab samples ~ 100 )
xenon HID arc ( continous ) 30-150
ideal white light 242 ( all energy converted to light )
ideal monochromatic 556 nm source 680 ( max eye sensitivity )
Xenon flash tubes are around 150, but because the flash is very short ~
1 msec, you can get very high peak intensities, not achievable by any
other source.
I havent found a number for the background intensity of the sky, or a
way of relating that to any of the above.
Borgelt Instruments - manufacturers of quality soaring instruments
phone Int'l + 61 746 355784
fax Int'l + 61 746 358796
cellphone Int'l + 61 428 355784
Int'l + 61 429 355784
email: [EMAIL PROTECTED]
website: www.borgeltinstruments.com
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