Medium Transport; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Aircraft Equipment Problem Less Severe
Aircraft Equipment Problem Dissipated
Aircraft; Environment - Non Weather Related
After lift off on Runway 35 at ILM ; we started getting unreliable RA readings. As we approached the departure end of the Runway; 'CAUTION terrain' GPWS popped up. I pitched for 20 degrees and verified we were maintaining a positive a rate of climb. We had a light Aircraft weight that day and took off half way down the Runway so I was confident we were above any obstacles. Once we were through about 500 ft. the RA altimeter was working appropriately. As a precaution I notified ATC of 'possible' 5g interference. Dispatch was notified as well. Upon evaluating the remainder of the flight there were no issues with the approach and landing phase. I did not feel a need for a write up on the RA alt. I was aware there were no 5g NOTAMS in ILM but never had issues with the RA before that produced a GPWS caution alert before so I covered all the bases for safety.
Air carrier Captain reported radio altimeter anomalies climbing out of ILM; citing 5G interference as the possible cause of the event.