Legal Interpretations
Letts 2012
Summary
The Question
Must a flight management system's navigational database be kept up to date, and may an iPad be used in place of an inoperative FMS?
Background
An individual asked whether the navigational database used by a flight management system must be kept up to date, or whether an iPad could be used in lieu of an inoperative FMS.
The FAA’s Interpretation
No iPad substitute is allowed. Under 14 CFR 91.213, any equipment, including navigational databases, required by the type certificate, supplemental type certificate, Airplane Flight Manual, or an operating rule must be operative unless it is an item operated in compliance with an approved MEL, and an iPad cannot substitute for required installed equipment.
- Requester
- Letts
- Issued
- November 11, 2012
- Subjects
- General Operating & Flight Rules · Air Carrier & Commercial Operations
Regulations Cited
- 14 CFR 91.213
- 14 CFR Part 121
- 14 CFR Part 125
- 14 CFR Part 135
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
Regulations Referenced
Snapshot retrieved August 6, 2026.