B737 Undifferentiated or Other Model
Flight Crew Last 90 Days 142
Confusion; Troubleshooting; Communication Breakdown
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Aircraft; Human Factors
From start to finish of flight including taxi out; ATC complained of a stuck MIC. It took us three to four frequency changes for us to realize that it was our aircraft. We investigated the possibility of it being us with stuck MIC every time a Controller said something about it and received successful radio checks each time. We ended up figuring out it was the FO's yoke switch and ended up disconnecting all his MICs and going to alternate mode on the FO's side and still had reports of hot MIC on our previous frequency that we had in radio number two; while we used radio number one. We advised ATC of our issue and landed uneventfully. When debriefing with Maintenance Control and his investigation into malfunction; it appears that a new yoke MIC switch (FO's side) was installed incorrectly the night prior; which led to a hot MIC connection without any activation of the switch. Basically the aircraft MIC was hardwired hot from the time power was applied to it. While we trouble shot it every time; ATC issued a warning we did not think it was us until we realized the issue was following us through our frequencies. Chief Pilot was contacted and debriefed accordingly; we also advised Maintenance and Dispatch to report the issue. [Recommend] Re-evaluate Maintenance Control's evaluation procedures as related to communication equipment repair and operation's check. ATC in all phases of flight putting out that someone had a stuck MIC.
Pilot reports that from start to finish of flight including taxi out; ATC complained of a stuck MIC. A new MIC switch was installed incorrectly on the First Officer's yoke the night prior; which led to a hot MIC connection without any activation of the switch on their B737 aircraft.