Date: 201303
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Aircraft: M-20 Series Undifferentiated or Other Model
Operator: Personal
Operating under: Part 91
Flight plan: VFR
Flight phase: Initial Climb
Airspace: Class D ZZZ
ATC / advisory: Tower ZZZ
Second aircraft: Brasilia EMB-120 All Series
Aircraft component: Air/Ground Communication
Component problem: Malfunctioning
Reporter organization: Government
Reporter function: Local
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Confusion; Communication Breakdown; Situational Awareness
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Other / Unknown
Detector: Person Air Traffic Control
When detected: In-flight
Result: Flight Crew Returned To Departure Airport; General Declared Emergency
Contributing factors: Aircraft; Human Factors
Primary problem: Human Factors

Narrative: A Mooney had arrived a few hours prior to this event. When he was inbound; his radio was so bad I couldn't understand 90% of what the pilot was saying. I advised the pilot of this; and after he arrived; he said he'd get that looked at. At the beginning of this event; after ascertaining in which direction the pilot wanted to depart; I asked if he had gotten his radios checked. The pilot replied in the negative; that he'd get them looked at when he reached his destination. He departed on a right downwind. When his transponder showed on RADAR; I advised him to squawk VFR. There was no response from the pilot; but the transponder started to ident; then changed to 1200. The pilot then started flying too far east; and was flying too close to final. I advised the pilot of that multiple times; and when there was no response; I asked the pilot to ident if he could hear me. After the second time I asked him to ident with no response; I gave the pilot traffic on an Embraer inbound on the ILS; and advised the Mooney to turn north immediately. He turned as I had instructed; and again; I asked him to ident. There was no response; however; the Mooney started to make a right turn back to the field when he was 3 miles north; and started descending through 1;400. At this point I advised Embraer to reduce to slowest practical speed; gave him traffic on the Mooney; and advised that the Mooney was NORDO. The Embraer did a great job slowing down. I advised Clearance Delivery/Ground Control that the Mooney was apparently returning to the airport. I asked the Mooney again to ident if he heard me; and he finally did. I then asked the Mooney to rock his wings if he was inbound to land because he was still identing. I observed the Mooney rock his wings; and cleared him to land. Once on the runway; his radios started working again. The pilot seemed very unfamiliar with even basic radio calls; and prior to departure had called Ground Control asking if 'we were visual.' Ground Control didn't understand what the pilot was asking; and queried the pilot. The pilot then came back with; 'Are we visual or instruments?' Assuming the pilot was asking if we were VFR (WX was 10 SM; BKN013) Ground Control advised we were VFR. I don't know if the pilot checked the ATIS before calling; but after he landed during this incident; he said something about not expecting the clouds. This pilot's actions were worrisome. I don't believe he should be allowed to fly without some sort of extra training. His actions put the many people on the Embraer at risk; and his unfamiliarity with basic procedures made him difficult to work with. Had there been any more traffic; things could've gotten very bad very quickly.




Synopsis: Tower Controller described a confused event when traffic departing apparently experienced radio difficulties and returned for landing. The reporter questioned the pilot's familiarity with ATC procedures.