Air carrier flight crew reported radar altimeter anomalies during cruise enroute to TYS airport in ZTL Class A airspace. The flight crew suggested possible 5G interference as a contributing factor.
Synopsis
Air carrier flight crew reported radar altimeter anomalies during cruise enroute to TYS airport in ZTL Class A airspace. The flight crew suggested possible 5G interference as a contributing factor.
Narrative
On flight from ZZZ to Knoxville TN; at around XApm local time; while in cruise between flight levels 310 and down to 240; the Captain and I received numerous alerts and warnings of ground spoiler fault; outboard flight spoiler fault; gear up/unsafe indication; flaps/slats indications of 00; radar altimeter buzzing alarm along with GPWS callouts. We were in VMC and indications did not reflect our current flight conditions. The total duration lasted less than a minute and occurred twice over a 5 minute window which we reported to Air Traffic Control Center. Upon investigation appeared to be radio interference with the radar altimeter from 5G or radio bands; due to the short anomalous nature. We pulled out the supplement guidance for our radar altimeter which did not pertain to our current phase of flight and was for a system failure instead of an anomaly; we continued enroute to destination without further occurrence. Upon arrival to destination the Captain notified the duty chief pilot as well as the relieving crew members at the airport of the anomaly and if it happened again to have maintenance look into it for a possible equipment issue.Cause: Radio interference with Radar Altimeter.Suggestion: Check location where event occurred for possible radio interference. Maintenance check aircraft radar altimeter equipment for functionality.
Second reporter narrative
On flight from ZZZ to Knoxville TN; at around XApm local time while in cruise between flight levels 310 and down to 240; the first Officer and I received numerous alerts and warnings of ground spoiler fault; outboard flight spoiler fault; gear up/unsafe indication; flaps/slats indications of 00; radar altimeter buzzing alarm along with GPWS callouts. We were in VMC and indications did not reflect our current flight conditions. The total duration lasted less than a minute and occurred twice over a 5 minute window which was report to Air Traffic Control Center. Upon investigation appeared to be radio interference with the radar altimeter from 5G or radio bands; due to the short anomalous nature. We pulled out the supplement guidance for our radar altimeter which did not pertain to our current phase of flight and was for a system failure instead of an anomaly; we continued enroute to destination without further occurrence. Upon arrival to destination I notified to duty chief pilot as well as the relieving crew members at the airport of the anomaly and if it happened again to have maintenance look into it for a possible equipment issue. Cause: Radio interference with Radar Altimeter.Suggestions: Check location event occurred for possible radio interference. Maintenance check aircraft radar altimeter equipment for functionality.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.