Date: 201906
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Weather elements / visibility: Thunderstorm; Turbulence; Windshear; 10
Light: Daylight
Aircraft: MU-2B 60 Marquise
Operator: Personal
Operating under: Part 91
Flight plan: IFR
Mission: Personal
Flight phase: Final Approach
Airspace: Class C ZZZ; Class D ZZZ1
ATC / advisory: TRACON ZZZ
Aircraft component: Air/Ground Communication
Component problem: Malfunctioning
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Private
Human factors: Situational Awareness
Anomaly: Aircraft Equipment Problem Less Severe; Inflight Event / Encounter CFTT / CFIT; Inflight Event / Encounter Weather / Turbulence
Detector: Automation Aircraft Terrain Warning
Result: Air Traffic Control Provided Assistance; Flight Crew Overcame Equipment Problem; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Aircraft; Human Factors
Primary problem: Aircraft

Narrative: I flew with family members [to] ZZZ. The weather in ZZZ1 at the time of departure was VFR and it was expected to have thunderstorms and rain at time of arrival. However; we continued into the flight. Upon arrival; the ZZZ airport was reporting 10 mi visibility and 10 kts. I was being vectored by ZZZ1 Approach to vectors to final RNAV XX. I used the second radio to communicate with ZZZ tower and they confirmed it was still 10/10 but warned us a thunderstorm was moving in fast. We continued the approach and noticed great drafts and wind shear that made impossible to land in ZZZ. I called a missed approach and we were instructed to continue with a heading of 130 and climb to 3;000 ft. I was transferred to ZZZ1 approach ATC and requested to land in ZZZ1. I was given vectors to final Rwy 17L. However; on the final phase of the vectors; before I was given a final vector to final (heading 90 degrees from final course to Rwy 17L in ZZZ1 and having descended to 2;000 ft); I noticed that the frequency was pretty silent for ZZZ1 and continued with the last assigned heading as no new heading was issued. I tried communicating with approach control without success. The heading I was on took me towards and near an antenna farm. My TAWS (Terrain Avoidance and Warning System) Alarm announced OBSTACLE; OBSTACLE! I decided to turn south immediately to maintain clearance with the terrain and started a climb to 2;500 ft in VMC to maintain clearance with terrain. I started troubleshooting the problem and realized I had a stuck PTT (Push to talk) button which made impossible to use the pilot side headset to communicate. I knew I could set my audio panel to Split Mode and use the copilot side headset to communicate. Once I set my audio panel to that mode; I took the copilot headset and used the PTT on the yoke on that side to communicate. I talked to approach again and was vectored back to ZZZ1 Rwy XYR. We landed uneventfully after encountering wind shear and heavy turbulence on final. After landing; I was asked to copy a phone number and call there after I had parked the plane. I spoke to a lady in approach control who asked me what had happened. I explained the situation and she mentioned that she was glad we were ok. She mentioned their terrain alarms had sounded and they were worried as we were headed toward the antenna farm and we were not communicating. The storm had moved in by the time we were being vectored for the second time and wind shear was felt with heavy turbulence on the final descent. The wind was smooth over the runway so landing was OK. I guess the problem was the inability to communicate due to a stuck PTT (push to talk) button until I sorted out a solution. A second factor was getting near the antenna farm.




Synopsis: MU-2 pilot reported a Terrain Avoidance and Warning System alert while flying in severe weather with a stuck mic.