5G Network Airworthiness Directive Mandates Transport Aircraft Manual Revision

The news of the month came when the FAA release airworthiness directives 01169-T and 01170-R, requiring all transport category aircraft to revise their airplane flight manual to prohibit operations in the presence of possible 5G interference.

The move comes in response to the possibility of interference with landing instrumentation as a result of newly introduced 5G cellular networks. Their close proximity in the radio bands could lead to incorrect radio/radar altimeter equipment during the landing approach, a dangerous condition that could result in changing aircraft handling due to the instrument's deep integration in automated landing systems. With certain makes and models even preparing the use of ground spoilers and thrust reversers prior to touchdown at appropriate altitude, the caution is a wise move in the interest of flight safety. 

IFALPA has issued a safety alert and the AFM revision document to be required for transport category (and helicopters equipped with a radio altimeter) aircraft for flight after January 5, 2022. The group notes that the change is not the completion of the procedural changes, saying "It is further anticipated that, depending on the aircraft, FAA may restrict the use of other aircraft systems as well with additional ADs."

Radar altimeter interference is dependent upon location, and the restrictions outlined in the AD will be activated by NOTAM for specific geographic regions and times. Canada recently restricted C-Band 5G transmissions in the vicinity of 26 airports, a move expected to be mirrored in the U.S.

The Association reminds its members that it is critical to be aware of the changes during flight planning and training, as well as possible alternate airports, weather minimums, and available instrument approach procedures. The level of radio altimeter integration could restrict available airports for some equipment installations. Pilots do not have a long period to acclimate to the new rules, facing the change within weeks. 

FMI: www.ifalpa.org