Legal Interpretations
Letts 2012
Page 1
0U.S. Department of Transportation Federal Aviation Administration · Nov ! ~ 2UJP.
Mr. Thomas D. Letts
Dear Mr. Letts,
Office of the Chief Counsel 800 Independence Ave., S.W.
Washington, D.C. 20591 This letter responds to your email requesting a legal interpretation as to whether the navigational database used by a Flight Management System (FMS) must be kept up to date or whether an iPad could be used in lieu of an inoperative FMS. 14 C.F .R. § 91.213 addresses the operation of aircraft with inoperative instruments and equipment and states in pertinent part that no person may ta.lee off an aircraft with inoperative instruments or equipment installed unless an approved Minimum Equipment List (MEL) exists for that aircraft, the aircraft has within it a letter authorizing operation of the aircraft under the MEL, the aircraft records available to the pilot include an entry describing the inoperable instruments and equipment, and the aircraft is operated under all applicable conditions and limitations contained in the MEL and the letter authorizing the use of the list. Further, under § 91.213(c), a person authorized to use an approved MEL issued for a specific aircraft under subpart K of part 91, part 121, part 125 or part 135 must use the MEL developed under those parts to comply with the requirements of § 91.213.
Therefore, any equipment, including navigational databases, required by Type Certificate, Supplemental Type Certificate, the Airplane Flight Manual or operating rule, except for an item operated in compliance with an approved MEL, must be operative under§ 91.213. An iPad cannot substitute for required installed equipment. We appreciate your patience and trust that the above responds to your concerns. If you need further assistance, please contact my staff at (202) 267-3073. This letter bas been prepared by Robert H. Frenzel, Manager, Operations Law Branch, Office of the Chief Counsel and coordinated with the Air Transportation and Aircraft Maintenance Divisions of Flight Standards Service.
ebecca B. cPherson Assistant Chief Counsel for International Law, Legislation and Regulations, AGC-200
Retrieved from ecfr.gov on July 18, 2026.