Air Traffic Control Fully Certified
Communication Breakdown; Troubleshooting
ATC Issue All Types; Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Provided Assistance; Air Traffic Control Issued Advisory / Alert; Flight Crew Landed in Emergency Condition; General Maintenance Action
Procedure; Aircraft
I was moving over to take Radar (TR)/CIC. Aircraft X was on a local IFR flight plan (cleared to KSUX via radar vectors) for practice ILS approaches. As I plugged in; [Controller A] asked Aircraft X how this approach would terminate. No response by the pilot. [Controller A] made several unanswered transmissions and I attempted to reach Aircraft X on the PET2000 portable radio located in the tower cab. No response was received by us. I observed Aircraft X's mode C then drop off their full data block and the target displayed ISR. Aircraft X was then observed making a right turn back inbound to KSUX. I relieved [Controller A] from the TR position; [Controller A] remained on as CIC; and verified with [Controller B] that Aircraft X was cleared to land on Rwy 13 which was approved by [Controller B]. I gave an unanswered broadcast to Aircraft X on TR frequency that tower advised Aircraft X was cleared to land on Rwy 13. [Controller B] on LC (Local) position began preparing to send light gun signals to the aircraft as Aircraft X approached Rwy 13. The pilot of Aircraft X then called the tower via the commercial telephone line; stating they had lost their alternator and their electrical equipment was becoming inoperative. I gave Aircraft X their landing clearance via telephone and asked if the pilot required any assistance. The pilot responded no assistance was needed. I then passed the telephone off to [Controller B] on the LC position and [Controller B] remained on the telephone with the pilot. Aircraft X landed without incident and taxied to the ramp under their own power. No recommendations. Current procedures were adequate for handling the incident.
SUX Controller reported a GA aircraft lost communications during practice IFR approach.