Title from PDF file caption (viewed Nov. 4, 2008).
Mode of access: Internet at the FAA web site. Address as of 11/4/08: http://www.airweb.faa.gov/Regulatory%5Fand%5FGuidance%5FLibrary/rgAdvisoryCircular.nsf/0/cd3cb6d36effa93186256d5500671ec1/$FILE/AC21-41A.pdf; current access available via PURL.