input: [Number] 25-15 [Office] ANM-111 [Date] 11-20-1989 [Title] 
output: Approval of Flight Management Systems in Transport Category Airplanes This advisory circular (AC) provides guidance material for the airworthiness approval of flight management systems (FMS) in transport category airplanes. Like all AC material, this AC is not mandatory and does not constitute a regulation. It is issued for guidance purposes and to outline a method of compliance with the rules. In lieu of following this method without deviation, the applicant may elect to follow an alternate method, provided the alternate method is also found by the Federal Aviation Administration (FAA) to be an acceptable means of complying with the requirements of Part 25. Because the method of compliance presented in this AC is not mandatory, the terms "shall" and "must" used herein apply only to an applicant who chooses to follow this particular method without deviation.