Date: 201901
Local time of day: 0601-1200
Flight conditions: VMC
Aircraft: A320
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
Aircraft component: Cockpit/Cabin Communication
Component problem: Improperly Operated
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural MEL / CDL
Detector: Person Flight Crew
When detected: Aircraft In Service At Gate
Result: General Maintenance Action; General Work Refused
Contributing factors: Aircraft; Procedure
Primary problem: Procedure

Narrative: This flight was the second group of flight segments with this nose number assigned to the Captain's ID. On Flight an MRM was sent in concerning the incorrect placement and safety wiring of the Emergency Evacuation Signal System - Flight Deck (EESS-FD) as described on page 6.10.XX.XX of the A-320 Flight Manual. Note 3 states this switch 'is safety wired to the CAPT PURS position.' This switch was observed in the incorrect position and safety wire generating the MRM input.On the following day nose XXXX was again assigned into the sequence of the crew's ID with an MEL applied to the incorrect positioning of the EESS-FD. This MEL placards the 'evacuation alarm signaling system inoperative'. This applied MEL significantly overstated the correction and needlessly restricted the flight crews access to and use of fully operational EVAC signally systems. The FM states 'The switch is powered and wired such that regardless of the physical switch position the CAPT PURS function is always enabled.' Thus the flight deck; and purser; EVAC COMMAND systems remain fully functional at all times. This was in fact verified by the flight crew with [Airport Maintenance] observing while at the gate.When this MEL was read 2 hours prior to scheduled departure during the flight planning process the Captain contacted Dispatch and [Maintenance] to discuss the implications of needlessly inopping a fully functional EVAC COMMAND switch. [Maintenance Control] agreed in the MEL assessment of over deferral and [Maintenance Control] would contact [Airport Maintenance] to re-address the deferral.Upon arrival at the aircraft the Captain did not observe any change to the MRD on the aircraft or any line maintenance personal working the discrepancy. [Airport Maintenance] was contacted to ensure they were aware of the issue whereupon the crew was informed that Maintenance personnel would shortly respond to the aircraft. When the two (2) Maintenance personnel arrived a discussion concerning the FM guidance; the actual operational capabilities of the aircraft; and safety implications of overall deferral for the EVAC COMMAND system took place. At the end of the discussion the 2 Maintenance personnel stated to the effect of; 'well you can just use the PA can't you? So that is good enough. We don't know of another MEL; our discussion is done and we are out of here.' Where upon the Maintenance personnel departed the aircraft; resent the MRD with MEL applied and releasing the aircraft for service.This over application of an MEL; although potentially covering the discrepancy; significantly limited some the possible normal and trained resources for the crew to use during an emergency situation. One solution could be ensuring a proper MEL is in place to address the placement of the CAPT PURS and CAPT SWITCH assuming this switch position cannot be corrected via simple placement and re-safety wiring. Or addressing the FM by revising the switch positioning to allow either CAPT PURS or CAPT ONLY since the switch is functional regardless of physical switch position.




Synopsis: A320 Captain reported an over application of an MEL and contacted Maintenance to address the deferred item.