Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Situational Awareness; Troubleshooting; Time Pressure; Communication Breakdown; Confusion; Distraction; Workload
ATC Issue All Types; Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued Advisory / Alert; Flight Crew Requested ATC Assistance / Clarification
Aircraft
Aircraft X was an arrival to MSL airport from the SE; winds were gusty from the SW and when I took over the sectors the previous controller had cleared Aircraft X to TUBYO for the RNAV 18 approach. MSL and nearly every other airport in Area 6 airspace was IFR. Due to the angle at which Aircraft X was approaching TUBYO he was required and attempted to execute the procedure turn at TUBYO before beginning the approach. After completing the turn and proceeding inbound on the approach and beginning to descend on the approach I noticed the aircraft turning off of the approach path and turning almost due northbound.The pilot reported back on the frequency and said his GPS was not working correctly and requested to reattempt the approach but without the procedure turn. I climbed Aircraft X back above the MIA and issued a series of radar vectors to the north of TUBYO that aligned Aircraft X with the approach path for the straight in GPS RWY 18 approach. I cleared Aircraft X for the GPS 18 approach but I again observed the aircraft turning off of the approach course and the pilot again reported back on my frequency stating his GPS unit had failed. I asked the pilot the nature of the equipment failure and if he would be able to execute an ILS approach. The pilot stated he could execute an ILS approach so I offered to provide vectors for the ILS RWY 29 approach at MSL which the pilot accepted.I issued an initial vector of 090 which the pilot acknowledged and began to fly. A few minutes later I attempted to issue further vectors and Aircraft X would not respond to or comply with. At this point I became concerned that Aircraft X had suffered further equipment malfunctions and had lost his radios. I have seen; especially modern aircraft; lose instruments in a cascading manner if power generation is lost and as the batteries die. Since Aircraft X was a [modern single engine low wing] I thought this is what happened. I instructed my D-side to begin looking for any airports with VFR conditions but none could be located within at least 100 miles.I knew if Aircraft X possibly had a backup handheld radio and we could at least communicate with them they could execute a surveillance approach to get through the overcast layer. I then instructed my D-side to ask HSV approach if they could provide Aircraft X; which now that he was NORDO we considered to be in emergency status; with a surveillance approach. I knew HSV's runway configuration was 18-36 which given the prevailing winds was preferable to the ILS 29 at MSL. The controller at HSV approach informed my D-side they were unable to provide a surveillance approach even to an emergency aircraft because they did not have the staffing to accommodate it. Eventually after about 10 mins of NORDO Aircraft X came back on the frequency and while not giving a reason for the departure from the frequency stated they were still able to attempt the ILS 29 at MSL. It took two attempts for Aircraft X to successfully execute the ILS approach but they did eventually land at MSL.If Aircraft X had actually suffered loss of all primary flight instruments and radios; which I have seen happen on modern glass cockpit GA aircraft; their only option if they would have had a backup radio would have been a surveillance approach at Fort Campbell; KY over 125 miles away which they may have not had the fuel or radio battery life to make. Ensure approach controls that are qualified to offer PAR/SAR surveillance approaches are adequately staffed to provide those services when they are needed.
ZME Center Controller reported of an aircraft that lost its radios; went off course; returned on frequency and then lost radios again. After 10 minutes of being out of contact; the pilot responded to ATC and eventually landed at destination.