Date: 201501
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Night
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Mission: Passenger
Flight phase: Parked
Aircraft component: Interphone System
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness
Second reporter function: First Officer
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Other / Unknown
Detector: Person Flight Crew
When detected: Taxi
Result: Aircraft Equipment Problem Dissipated; General Flight Cancelled / Delayed; General Release Refused / Aircraft Not Accepted; General Maintenance Action
Contributing factors: Aircraft; Company Policy; Human Factors
Primary problem: Ambiguous

Narrative: Everything seemed normal with the aircraft; all associated preflight items were checked and we prepared for departure. I was concerned with destination weather which was pretty much at minimums; with blowing snow and low ceilings; we had plenty of fuel and (to my knowledge at that time) a great aircraft. During the pushback; I couldn't talk to the Pushback Crew. I could hear but not talk. I rechecked the O2 mask; tried the #1 avionics panel and aborted start and told Ground Crew to standby. After trying the spare headset in the cockpit and having no luck with that; we had the Agent pull the jetway back up and call for Contract Maintenance. She did that while I initiated contact with the Operations Center/Dispatch. Anyway; I got them on the horn; told them my troubles with the COMM panel and they agreed after several quick trouble shooting procedures; (including asking me if the mask was working and would I consider using that for the flight) that having Contract Maintenance look was needed. Shortly thereafter; the local Maintenance Contractor shows up; swaps out COMM panels from observers panel to #1 and we still have no COMMS. Here is where the fun starts. I tell Maintenance that I am 'uncomfortable' taking an -800 aircraft; at high weights into a field with bad weather at or near minimums with snow on the ground. They say; 'Captain; that item is deferrable so we'll just MEL it and get you moving.' I tell them I'm not taking the aircraft under those conditions where I don't have NORMAL communications with my First Officer (FO). About this point they connect me with the Chief Pilot on Call. He was great; he didn't pressure me to take the aircraft; but he did line up options. One of which is that they may swap me out. Unbeknownst to me; they got Scheduling into the loop; and instead of heeding my concerns about weather and conditions (which as most Pilots know; will actually get worse right about early sunrise due to sun angle in the haze; mist and snow) they decide that the best course of action is to get another UNSUSPECTING Pilot to take an aircraft that I won't fly into those conditions in its current state. So the swapping starts and a Captain shows up at the aircraft not knowing what's going on. I tell him what is happening; and he jumps into the seat and whether he fixed/touched/moved something; I don't know but he says COMMS are back. We switch seats and sure enough; everything is working. I tell him to go back to his original aircraft; I call Dispatch tell them that we're now good to go and let them re-sort all that. We re-board all the Passengers and get under way about two hours behind schedule. The issue here is that Safety seems to have been left behind here. I had VALID concerns about abnormal COMMS in really pretty crappy weather conditions. They didn't care; they had MEL relief and they wanted to go. The undermined safety. I can think of a thousand things that can go wrong and without normal; smooth instantaneous COMMS with my First Officer; it can go sideways pretty quickly. But our Knowledge/Experience/Skills are discounted over schedules.  That's it; just that our inputs are not really weighed into the equation when the Company makes decisions without utilizing any of our amplifying information. More authority to PIC.  If he says it's not doable; no argument from Company Operations.  Get Mechanics/parts etc. headed that way after 'reasonable' trouble-shooting and discussion with the Chief Pilot on Call.


Second narrative: As the Captain called for pushback; he realized he was unable to speak on his side of the aircraft. We troubleshot the switches; headsets; etc.; even plugging in his set on my side; and trying the alternate headset from the seat back. After conferring with Dispatch and Maintenance; we tried the oxygen mask MIC which worked. Once the O2 mask was re-stowed; the boom MIC ceased function again. Contract Maintenance was called; and several procedures tested; including swapping out control heads; pulling and re-stowing the O2 mask and nothing worked. The weather conditions at destination were at minimums with precipitation. The Captain told Dispatch that he was uncomfortable taking the aircraft as-is into these conditions; a decision with which I concurred. He was on the phone with the Chief Pilot on Call; who asked me if I would be comfortable taking the aircraft with another Captain and I told him that I agreed with the many years of experience standing next to me. About this time; a new Captain; obviously pulled from another flight in order to take the aircraft we were scheduled for showed up. He sat in the Captain seat for a minute; and I'm not sure what exactly he did; if anything; but he said; 'it's working now.' We took the aircraft and flew it down to minimums and landed uneventfully. On a clear day; things look a lot different; but when the snow is flying and the visibility is at minimums; some things expand in importance. Under these conditions; a very experienced Captain told the Company he was uncomfortable taking a certain deferrable Maintenance problem into the current conditions. The decision to disregard his judgment and find another Captain with a somewhat different comfort level seems imprudent at best and hazardous to the Company's stated number one goal. Disable the auto switching function from boom to mask on the aircraft that have it.


Synopsis: During pushback; a B737-800 Captain discovers that his microphone is inoperative; although the oxygen mask microphone is operative. Maintenance is called but the problem cannot be rectified and plans to defer the mic. With poor weather at the destination the Captain refuses the aircraft. Another Captain is found to take the aircraft but is able to get the mic working and the flight departs with the original Captain. The reporter does not believe that the company should attempt to find another Captain after the aircraft has been refused.