Small Aircraft; Low Wing; 1 Eng; Retractable Gear
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 16.5
Communication Breakdown; Confusion; Troubleshooting
ATC Issue All Types; Deviation - Altitude Excursion From Assigned Altitude; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Provided Assistance; Flight Crew Took Evasive Action
ATC Equipment / Nav Facility / Buildings; Weather
I had just taken over the sector when I noticed Aircraft X climbing. I checked with him to see if he needed a higher altitude. I'm not sure if it was our radios; but I was only able to get broken responses from him. During (or maybe after we got off the recorded line) the briefing I asked [another Controller] what the tops were; and he said a jet was deviating and had turned direct SHV at FL430; so it must be up to that. I noticed Aircraft X turning toward the weather; and I told him that it appeared that he was turning into the worst of the weather. He made a garbled response that I thought was him saying something like; 'I'm turning away' He appeared to be turning away; making a 360. I also noticed Aircraft X descending. He said he was spinning and I thought he said he was descending. He also said he couldn't see the horizon or the ground. Another aircraft said they heard him saying Mayday; but I did not hear this. [The other Controller] was still in the area; so he took my d-side.I recommend better frequencies in that area.
ZFW Controller reports of radio problems with aircraft that is entering bad weather; Controller does not hear pilot say Mayday.