FAA warns pilots, aircraft operators and manufacturers that 5G cellular technology may cause interference with sensitive electronic equipment and compromise safety systems.
The FAA stated that operators should be aware of the possibility of interference from 5G transmitters or other technology causing certain safety equipment malfunction. They must take mitigation actions that could impact flight operations.
The FAA issued a Special Airworthiness Information Bulletin on Nov. 2 regarding the Dec. 5 deployment plan for 5G wireless broadband networks at a higher frequency than previously allowed. This is known as the C Band spectrum.
The deployment will be carried out by selected providers licensed by Federal Communications Commission in 46 markets.
The new frequency range is close to the current-generation broadband range. It also includes frequencies used by aircraft operators for radio altimeters. These altimeters measure the distance of a plane from the ground at altitudes between approximately 2,500 and 2,500 feet.
FAA Bulletin reminds aviation industry stakeholders that equipment dependent on radio altimeters could be damaged, particularly during low-altitude operations.
In addition, the bulletin notes that there have been no reports of interference to altimeters caused by wireless broadband operations. Some countries have placed temporary power and proximity restrictions on broadband networks that operate within the C-Band spectrum.
FAA recommends that pilots remind passengers that any portable electronic device equipped with 5G must be switched to airplane mode or turned off during flight. FAA also urges aircraft operators to report interference immediately.
Equipment manufacturers must continue to test for 5G interference susceptibility.
Before the FCC auctioned off C-Band frequencies in February, airlines and other aviation professionals expressed concerns about FCC's plans to open higher frequencies up to broadband providers.
Wednesday's statement by the Air Lines Pilot Association (ALPA union) stated that the FAA's guidance was a positive step.
ALPA stated that "The FAA could have to impose additional restrictions upon flight operations once transmissions start to maintain safety because of inadequate requirements on 5G which limit interference with radio altimeters."