Commercial Fixed Wing
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Flight Crew Last 90 Days 32; Flight Crew Total 1645; Flight Crew Type 1645
Human-Machine Interface; Distraction
Aircraft Equipment Problem Less Severe
Air Traffic Control Provided Assistance; Flight Crew Overcame Equipment Problem; Flight Crew Requested ATC Assistance / Clarification
Aircraft; Environment - Non Weather Related
While cruising at FL390 about 20 miles NE of CLT had a possible 5G interference with our radar altimeter. Radar altimeter displayed for about 45 seconds to a minute and showed fluctuations between 1;400-1;790 [ft.] AGL. This also caused the aircraft to think it was close to the ground and displayed the landing ECAM (Electronic Centralized Aircraft Monitor) instructing that the plane wanted the gear and flaps down as well as the spoilers to be armed. The anomaly went away after about a minute. Per our pilot bulletin we notified ATC; Dispatch; Operations; and made a Maintenance write up.
During cruise flight at FL390 the 'landing memo' suddenly appeared on the upper ECAM (Electronic Centralized Aircraft Monitor) screen. I immediately checked for a radio altitude indication (there should be none above 2;500 ft.) and found it to be displaying 1;750 ft. This indication lasted for approximately 45 seconds before disappearing and all indications returning to normal. After advising ATC of this occurrence; the Atlanta Center controller said he had heard we were in a 5G 'hotspot' area; although he said most reports of interference were at FL380.
Flight crew reported possible 5G interference at cruise; 20 NM North of CLT.