wrote in message
oups.com...
Do a google search on the subject, there is a tremendous amount of
information on the subject on the Internet.

Go to AVweb (www.avweb.com), click on "columns", then on "The Pilot's
Lounge" and scroll down to one of the very first ones which addresses
the subject in detail.

http://www.avweb.com/news/columns/182653-1.html