IFALPA published a Safety Bulletin regarding radar altimeter interference from 5G signals.
Radar altimeter interference from 5G signals can take the form of loss of radar altitude information, or worse, incorrect radar altitude information unknowingly being generated. There have been fatal accidents associated with incorrect radar altitude, most recently Turkish Airlines flight TK1951 in Amsterdam in 2009.
Altitude information derived from radar altimeters has been deeply integrated into aircraft systems and automation, with the latest aircraft using it to change aircraft handling qualities and prepare systems such as ground spoilers and thrust reversers for deployment prior to touchdown. This is in addition to radio altimeter use for autoland and in Category (CAT) II/III and Required Navigation Performance (RNP) AR approaches.
The FAA have issued an Airworthiness Directive (AD) intended to cover all transport category aircraft which will require an Airplane Flight Manual (AFM) revision effective 5 January 2022.
We encourage you to take note of this important Safety Bulletin.
