Narrative:

Approximately 10 minutes prior to scheduled departure; I went to the forward galley to address the guests(passengers). The passenger address (PA) system; which was working during all of the lead flight attendant addresses; was not working. The lead attendant tried to use the PA and could not get it to work. The PA would not work from the aft galley station or the flight deck. Maintenance was called to the airplane. During the diagnosis of the PA problem; it was also noted that the interphone between the flight deck and either galley stations was not working. All the call systems from flight deck to cabin and cabin to flight deck were working properly. A system reset was attempted but did not fix the problem. Maintenance control was contacted and the decision was made to defer the system and proceed with the flight. The MEL 23-31-01-01 was reviewed between the pilots and alternate means of communication were briefed to the flight attendants. I discussed the paragraph 1. A. Of MEL 23-31-01 'alternate normal and emergency procedures; ...' with maintenance control. At that moment we both concurred that the alternate means of communication that was briefed with the flight attendants regarding the inoperative interphone; met the intent of this paragraph. With that understanding maintenance control deferred the write-up and I accepted the deferral.after takeoff (T/O); with a little more time to devote to the MEL; I noticed that the interphone is covered under MEL 23-43-02 and was not deferrable in the state it was in. After landing I called maintenance control to review this issue with them. We seemed to have a consensus that MEL 23-31-01-01 should not have been used to defer the interphone. The original problem was the inoperative PA and initial effort to fix or defer was focused on the PA. Additionally; the interphone was noted as also inoperative. Upon review of the situation; it seems as if the decision to defer both interphone and PA with MEL 23-31-01-01 was made too quickly and without thorough reference to the entire (MEL) section 23. As I read through the MEL; without time concern for on-time performance; the MEL 21-31-01 clearly does not provide relief for an inoperative interphone. The PA and the interphone are two different systems and should have been written up independently. Is there a potential that the next failure of the PA system could also cause a failure of the interphone without the crew being aware? It was purely by chance that the crew and maintenance noticed the interphone problem when maintenance had been called out to address a PA malfunction. Since the problem fixed itself after landing; it may be difficult to determine exactly what the problem was. One fact we know is that both the interphone and the PA experienced an unusual failure after they both had recently been working. To avoid a potential repeat of this problem; I suggest we add an additional operations procedure to MEL 23-31-01: 'verify the interphone is working between the flight deck and cabin. If any function of the interphone does not work properly; refer to MEL 23-43-02.'

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Original NASA ASRS Text

Title: A Captain reports that during trouble shooting of an inoperative Passenger Address system on their A319; Maintenance and the flight crew noticed the interphone between the flight deck and the forward and aft galley stations was also not working. Flight departed with both systems not operative under an incorrect MEL 23-31-01.

Narrative: Approximately 10 minutes prior to scheduled departure; I went to the Forward Galley to address the guests(passengers). The Passenger Address (PA) system; which was working during all of the Lead Flight Attendant addresses; was not working. The Lead Attendant tried to use the PA and could not get it to work. The PA would not work from the Aft Galley station or the Flight deck. Maintenance was called to the airplane. During the diagnosis of the PA problem; it was also noted that the Interphone between the Flight deck and either Galley stations was not working. All the Call systems from Flight deck to Cabin and Cabin to Flight deck were working properly. A system reset was attempted but did not fix the problem. Maintenance Control was contacted and the decision was made to defer the system and proceed with the flight. The MEL 23-31-01-01 was reviewed between the Pilots and alternate means of communication were briefed to the Flight attendants. I discussed the paragraph 1. A. of MEL 23-31-01 'Alternate normal and Emergency procedures; ...' with Maintenance Control. At that moment we both concurred that the Alternate means of communication that was briefed with the Flight Attendants regarding the inoperative Interphone; met the intent of this paragraph. With that understanding Maintenance Control deferred the Write-up and I accepted the deferral.After Takeoff (T/O); with a little more time to devote to the MEL; I noticed that the Interphone is covered under MEL 23-43-02 and was not deferrable in the state it was in. After landing I called Maintenance Control to review this issue with them. We seemed to have a consensus that MEL 23-31-01-01 should not have been used to defer the Interphone. The original problem was the inoperative PA and initial effort to fix or defer was focused on the PA. Additionally; the Interphone was noted as also inoperative. Upon review of the situation; it seems as if the decision to defer both Interphone and PA with MEL 23-31-01-01 was made too quickly and without thorough reference to the entire (MEL) Section 23. As I read through the MEL; without time concern for on-time performance; the MEL 21-31-01 clearly does not provide relief for an inoperative Interphone. The PA and the Interphone are two different systems and should have been written up independently. Is there a potential that the next failure of the PA system could also cause a failure of the Interphone without the crew being aware? It was purely by chance that the crew and Maintenance noticed the Interphone problem when Maintenance had been called out to address a PA malfunction. Since the problem fixed itself after landing; it may be difficult to determine exactly what the problem was. One fact we know is that both the Interphone and the PA experienced an unusual failure after they both had recently been working. To avoid a potential repeat of this problem; I suggest we add an additional Operations Procedure to MEL 23-31-01: 'Verify the Interphone is working between the Flight Deck and Cabin. If any function of the Interphone does not work properly; refer to MEL 23-43-02.'

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.