The FAA has proposed a revision of Master Minimum Equipment List Policy Letter-98, Navigation Databases (MMEL PL-98) that would eliminate the ability of operators to defer updating of expired navigation databases in accordance with a minimum equipment list. This capability is useful when operators are on multi-week trips in areas of the world where updates are difficult or impossible to accomplish due to lack of qualified facilities and limited Internet access. 

“The revision to Policy Letter-98 proposes to remove relief for expired navigation databases from Minimum Equipment Lists (MELs),” NBAA noted in a June 30 letter to the FAA. NBAA said this revision also conflicts with a 2012 FAA legal interpretation “which explicitly states that an aircraft may not be operated with an expired navigation database unless operated in compliance with an approved MEL.” If the new policy is adopted, operators may find their aircraft grounded until the database can be updated, “resulting in significant financial impacts and lost operational efficiency.

"NBAA believes that aircraft operators should be able to operate with an expired navigation database to facilitate private and commercial air travel, with additional steps taken to ensure navigational accuracy and safety," the association said. "These steps include complying with any published provisions in the Airplane Flight Manual (AFM) when operating with an expired navigation database, or if not specifically published, establish procedures to ensure navigational accuracy by verifying navigational waypoints with current aeronautical publications such as en route and terminal charts.”

If operators are forced to comply with the new policy, this might “result in potentially unsafe operating behaviors,” NBAA contended. Either grounded aircraft will cause an extra burden on FAA inspectors when operators seek special flight permits to return to a location where the database can be updated, or operators may try to fly VFR. “Aircraft operated under IFR have an increased safety net and take advantage of an enhanced margin of safety resulting from increased minimum separation standards provided by the air traffic control system. The FAA enacted regulations to encourage operators to fly under IFR for safety reasons and during periods of inclement or unfavorable weather conditions. Additionally, the FAA encourages flying IFR because it provides a greater level of safety for passengers compared to the alternative.” Flying VFR would also be harmful to the environment as these flights would have to be conducted below FL180, where fuel consumption is far greater.