Try this source. It's from FAA AC 43-13 and explains the process pretty nicely. Not a turbine aircraft, but the principles remain the same.. .. . <a href="http://av-info.faa.gov/dst/43-13/Ch_10-01.doc" target="_blank">FAA AC43-13</a> . .. . <a href="http://av-info.faa.gov/dst/43-13/Ch_10-02.doc" target="_blank">Chapter 10-02</a>