Gulfstream IV / G350 / G450
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe
Aircraft
After landing ZZZ while taxiing into [FBO]; ground control asked us to call them on a different frequency after we shut down. Upon contacting them; they advised us that our aircraft had been transmitting a constant data stream on Controller Pilot Data Link Communications (CPDLC) from the time we left ZZZ2 to ZZZ1 to ZZZ. This occurrence caused interference to all other aircraft in the area of our location as we traveled. According to ATC; there were many aircraft who were unable to receive their CPDLC communications during the time our aircraft was in their vicinity. The Controller stated to us that 'We completely shut down [two major airports]' from utilizing CPDLC for all flights requiring its usage. We are unaware if we had the same affect in [other areas]. ATC had been trying to track down this problem for some time. Once we landed in ZZZ; they pinpointed it to be our aircraft as the cause of the trouble. Upon communicating with them; they informed us of the situation.We called [Company] Maintenance and discussed this with the Maintenance Controller on duty. After a full description of the issue; he said he would contact some folks and call us back as soon as he could. While waiting for his call we decided to completely shut down the aircraft to full dark for the first time since our original start up in ZZZ2 some 7 hours earlier. After letting everything sit completely unpowered for a few minutes; we restarted the APU and brought all systems back on line.We contacted ATC and they indicated our aircraft was no longer broadcasting CPDLC data. We called [the Maintenance Controller] and relayed our findings to him along with the controller's comments. [He] gave us a suggestion if it were to happen again; we could change our com 3 setting from Data to Voice. This should resolve the issue by stopping any continual data transmissions if the situation were to reoccur. We departed a short time later with no further issues. I think we should follow up with Gulfstream and possibly the FAA to try and figure out why this happen to try and make sure we don't repeat it. As of now it is still a mystery.
G450 Captain reported the aircraft Controller Pilot Data Link Communications system was continually transmitting data thus blocking other data link communications from reaching other aircraft. Captain reported a complete shutdown of the aircraft fixed the problem.