Date: 201306
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
ATC / advisory: TRACON ZZZ
Aircraft component: Air/Ground Communication
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Human-Machine Interface; Communication Breakdown; Training / Qualification
Anomaly: ATC Issue All Types; Aircraft Equipment Problem Less Severe
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Overcame Equipment Problem; General Maintenance Action
Contributing factors: Aircraft; Human Factors; Procedure
Primary problem: Aircraft

Narrative: While in cruise flight from to ZZZ; I noticed that my yoke intercom/radio mike stopped working. I tried moving it both up and down; but it had completely died. The Captain and I agreed to continue the flight and write up the discrepancy when we arrived in ZZZ. While on descent into ZZZ; I noticed the sound of the radio side tone had changed. It was apparent that we were transmitting on the approach control frequency. We immediately began troubleshooting the problem. I pulled out my headset cords in order to isolate the problem. The Captain did the same. That did not help. We tried placing the Approach Control frequency on radio number 2. We were then able to hear ATC; but knew that radio number 1 was still keyed hot mike. Eventually the mike came unstuck. We advised ATC of the problem. They then instructed us to simply answer instructions with an 'ident.' We complied. We continued the arrival; approach; and landing using this method. When we arrived on the ground and taxied clear of the runway; the Captain pulled the radio number 1 circuit breaker. This seemed to stop the hot mike situation. Eventually I discovered that the number 2 radio control knob transmitted on hot mike whenever it selected a radio. We then selected radio number 1 when we didn't want to transmit as it was disabled. I then selected radio number 2 with the radio number 2 control knob when I needed to transmit. We successfully communicated with ATC and taxied back to the gate using this method. When we arrived at the gate we wrote up the problem and advised Maintenance. When the Mechanic arrived at the aircraft we debriefed the problem to him. The Mechanic advised that he'd simply defer the First Officer's mike. We advised him that this was unacceptable. We did not want this aircraft to jam the ATC frequencies as we had done on arrival. The Mechanic eventually agreed. I learned that sometimes we have to rely on experience and systems knowledge in order to remedy problems in the aircraft. Yes; we follow company policies and procedures when we can and when the situation warrants. However; in this situation common sense; systems knowledge; and experience were what helped remedy the situation.




Synopsis: A CRJ-200 flight crew overcame transmitter problems with their primary ATC radio by using some creative troubleshooting. Once on the ground they assured the problem was repaired and not passed on to the next crew.