Medium Large Transport; Low Wing; 2 Turbojet Eng
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Flight Crew Last 90 Days 166; Flight Crew Type 6971
Troubleshooting; Distraction; Human-Machine Interface
Aircraft Equipment Problem Less Severe
Flight Crew Overcame Equipment Problem
Environment - Non Weather Related; Aircraft
Holding short of Runway 27 IAH Aircraft Y reported 5G interference with flight instruments. We were cleared for takeoff and climbing through 400 ft. the mode control panel altitude window indicated 50;000 ft. on its own and the altitude alerter sounding continuously. I selected level change due to VNAV dropping offline and the absence of the flight director pitch bar. Upon re-selecting the cleared altitude in the altitude window the pitch bar was restored and VNAV was re-selected as the pitch mode. This event was reported to ATC; Dispatch; and an ELB entry was entered.
Air carrier Captain reported during departure from IAH the mode control panel altitude window indicated incorrectly and the altitude alerter sounded continuously.