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Old September 22nd 06, 11:13 PM posted to rec.aviation.soaring
Doug Haluza
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Posts: 175
Default End of Season Sunset Warning for SSA-OLC Participants


Doug Haluza wrote:
Andy wrote:.

It is interesting that part 61 and part 91 define regulations that
refer to sunrise and sunset but that the FAA provides no definition of
what those terms mean. At least I couldn't find those definitions. I
expected to find them in part 1.


This is true; the FAR's do define "Civil Twilight" be referring to the
"American Air Almanac" but do not define Sunrise or Sunset (they
probably didn't anticipate ****house lawyers trying to make this an
observable rather than a predictable phenomenon). It is reasonable to
assume that the American Air Almanac should also be used as the
official source for Sunrise and Sunset as well. It uses the standard
defenition of when the sun is at a zenith angle of 90.8333 degrees.
This definition is the basis for the calculation used by the USNO, who
also publish the American Air Almanac.


Given the uncertainty of the actual official sunset time I repeat my
request that SAA's sunset time be used only to determine the "end of
soaring flight" and not used to determine the validity of the entire
flight.



I would personally like to see the time of sunset be the limit for the
end of soaring flight for the OLC universally. This would make
competition the same worldwide, regardless of night flying rules. That
said, however, the SSA Board took a very clear position on FAR
violations in general, and particulalry on Sunset, and your request is
not supported by the SSA policy.