Date: 201401
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
Aircraft component: Cockpit/Cabin Communication
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Troubleshooting
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural MEL / CDL
Detector: Person Flight Crew
When detected: Aircraft In Service At Gate
Result: General Release Refused / Aircraft Not Accepted; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft; MEL; Procedure
Primary problem: Aircraft

Narrative: Reviewing our release for our first flight of the day I noticed several MELs on the inbound aircraft; one of which indicated that the Passenger Address System was Inop. Upon arrival at the gate; I noticed the 'A' Flight Attendant communicating with the passengers via the hand held megaphone. Maintenance was called and the Mechanics repaired the PA system and removed the associated MEL. Shortly after the mechanics left; the PA system once again failed and I again requested Maintenance. The Mechanic stated they did not have the parts required to repair the aircraft and was going to apply the previously removed MEL back onto the aircraft. A review of the logbook displayed numerous entries for this system over the previous five days. While reviewing the provisions of the MEL; I noted that one requirement was for the Chime System to operate 'normally.' I performed a test of the system and was informed by the three flight attendants that they did not hear any signals from the cockpit. I did hear the chime in the cockpit so I entered mid-cabin and had the First Officer attempt the test a second time. The second test confirmed the system was not functioning in the cabin. While performing this test; several passengers informed me 'that hasn't worked since we left XXX'.I returned to the jetway and expressed my concerns to the Mechanic that in my opinion we were not in compliance with the MEL as stated due to the Chime System not functioning 'normally.' He stated he agreed but had been overridden by Headquarters. At this point I called Dispatch and requested a patch through to Maintenance. While discussing the MEL with Maintenance; it was apparent that they wanted the aircraft flown as is. When I told him of the failed test of the system his response was; 'Well; the Mechanic said he heard a chime and that's good enough for me.' I told him that the two tests we performed demonstrated that the flight attendants could not hear the chimes and in my opinion the system was not operating 'normally' as per the MEL. At that point Maintenance started what I could best describe as pressure by guilt; saying such things as; 'So; you have no problem stranding all those passengers;' 'You don't feel bad that all those people are not going to get to see their families on time'; etc. I told the Mechanic the only thing I wasn't going to do was fly an aircraft in direct violation of an FAR and risk my certificate. His response was; 'That's not going to happen.' His next and last response was; 'Throw the keys on the dash as you walk out. You're done.' I informed the Mechanic at the aircraft with me of the outcome to which he replied; 'I agree with you; the system is not operating normally'. The aircraft was removed from service and all of our passengers were moved to another aircraft.Maintenance needs to understand that it is NEVER my intention to inconvenience our passengers; but SAFETY overrides all other concerns. Flight attendants using the emergency megaphone for routine cabin announcements drain the battery of the device rendering it unusable in the time of a real emergency. In addition; the lack of a way to communicate with the cabin crew and passengers during flight [or during an evacuation] endangers everyone onboard in the event of a real emergency.




Synopsis: The Captain of a Boeing 737 discovered the chime portion of the Flight Deck to Cabin PA System had been written up as inoperative numerous times; and despite an unsuccessful attempt to repair the system; remained MEL'd. Provisions of the FAA approved MEL required that it operate 'normally'; and when tested was determined to still be inoperative in the Cabin.