Narrative:

Upon arriving at the aircraft; maintenance had the logbook and was completing the ETOPS pre departure clearance (pre-departure check); there was a colored placard indicating that preflight duties were allowed. Without having the ability to have reviewed the logbook; but flown the aircraft the previous day; I was expecting the number 1 thrust reverser to be on MEL. Looking at the engine (engine) panel [P5 aft overhead panel]; I noticed an MEL sticker next to an illuminated reverser light. The previous day; having flown the same exact aircraft with the same MEL applied; this light was not illuminated. Knowing that the MEL allows for the engine annunciator on master recall; it did not state what lights were acceptable on the engine panel. I was curious if the change in condition from the previous day was a known event to maintenance and still met the criteria in the MEL. At this time; maintenance came back with the logbook and stated that the pre departure clearance was complete and mentioned that the number 1 thrust reverser was on MEL. I explained that I had flown this aircraft the previous day with the same MEL and the reverser light was not illuminated; but today it is; and asked if this is a known configuration under the MEL. Even though circuit breakers (C/bs) were pulled and the thrust reverser secured; I wanted to confirm that the isolation valve was not open when it didn't need to be (as indicated by the reverser light); especially for an ETOPS flight. He stated that he was not sure; but needed to call base maintenance in ZZZ2 to notify about the pre departure clearance sign-off and would ask them. I continued with the exterior preflight and did not hear his exact conversation with base maintenance. When returning to the flight deck; maintenance stated that work had indeed been done overnight and that [reverser] light should not be illuminated. Over the next few hours maintenance worked on the [reverser] system to try and resolve the discrepancy. At some point; maintenance realized that the system was okay under the MEL in the condition that it was and re-released the aircraft into service. At this point; and a few hours delayed; I was given the logbook and was able to review it. Maintenance had already written up the event and signed it off as they had the logbook the entire time. It all seemed complete; so we departed. Upon arriving at ZZZ1 destination; maintenance met the aircraft and wanted a debrief of the situation. I explained the events as above. When reviewing the write-up and corrective action with maintenance; it was pointed out [to me] that [we] the flight crew [had] commented on the number 1 engine con (control) light - which I had not (I only mentioned the reverser light). When I read this before departure; I didn't catch the difference in the wording that maintenance [had] described versus the condition I had initially described and had been dealing with for the past few hours. In the MEL; there is mention of a maintenance work order. None of the details are presented to the flight crew. Upon arrival; maintenance stated that per the maintenance manual (M/M) the reverser light may be illuminated; but the engine control should not; and surmised that; that was what the miscommunication between maintenance and maintenance control was about. This could have been prevented by a clearer communication line between maintenance control (ZZZ2); local maintenance; and the flight crew. In the MEL; as presented to the crew; there is mention of a maintenance procedure located in the maintenance manual; but it also is not very clear on the outcome of the setup as the flight crew may see things. In this example; MEL 78-1B states the work order to deactivate and secure the thrust reverser in the maintenance manual (MM); then continues to state that the engine annunciation can be illuminated during master recall. But; it does not state what lights on the engine panel are acceptable to have; or not have [illuminated]. The maintenance manual states that the reverser light is okay; while an eec anomaly (engine control) is not okay. It would be helpful if the MEL stated what non-normal lights are acceptable or not acceptable (in addition to the annunciation panel's master recall). Also; for completeness; it would be nice to know which C/bs are involved per the maintenance manual procedure so that during preflight; it is easier to verify that all the correct C/bs are collared (or closed); are indeed correct for the known situation.

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Original NASA ASRS Text

Title: A First Officer and a Captain describe their efforts and frustration with Maintenance Control; Local Station Maintenance and Operations to resolve an illuminated REVERSER light that appeared during an ETOPS PDC (Pre-Departure Check) on a B737-800 aircraft. First Officer noted it would be helpful if the MEL stated what non-normal lights are acceptable or not acceptable on the P5 Aft Overhead ENG panel; for an MEL 78-1B Reverser deferral.

Narrative: Upon arriving at the aircraft; Maintenance had the logbook and was completing the ETOPS PDC (Pre-Departure Check); there was a colored placard indicating that preflight duties were allowed. Without having the ability to have reviewed the logbook; but flown the aircraft the previous day; I was expecting the Number 1 thrust reverser to be on MEL. Looking at the ENG (Engine) panel [P5 Aft Overhead Panel]; I noticed an MEL sticker next to an illuminated REVERSER light. The previous day; having flown the same exact aircraft with the same MEL applied; this light was not illuminated. Knowing that the MEL allows for the ENG annunciator on Master Recall; it did not state what lights were acceptable on the ENG panel. I was curious if the change in condition from the previous day was a known event to Maintenance and still met the criteria in the MEL. At this time; Maintenance came back with the Logbook and stated that the PDC was complete and mentioned that the Number 1 thrust reverser was on MEL. I explained that I had flown this aircraft the previous day with the same MEL and the REVERSER light was not illuminated; but today it is; and asked if this is a known configuration under the MEL. Even though circuit breakers (C/Bs) were pulled and the thrust reverser secured; I wanted to confirm that the isolation valve was not open when it didn't need to be (as indicated by the REVERSER light); especially for an ETOPS flight. He stated that he was not sure; but needed to call Base Maintenance in ZZZ2 to notify about the PDC sign-off and would ask them. I continued with the exterior preflight and did not hear his exact conversation with Base Maintenance. When returning to the flight deck; Maintenance stated that work had indeed been done overnight and that [REVERSER] light should not be illuminated. Over the next few hours Maintenance worked on the [Reverser] System to try and resolve the discrepancy. At some point; Maintenance realized that the system was okay under the MEL in the condition that it was and re-released the aircraft into service. At this point; and a few hours delayed; I was given the Logbook and was able to review it. Maintenance had already written up the event and signed it off as they had the logbook the entire time. It all seemed complete; so we departed. Upon arriving at ZZZ1 destination; Maintenance met the aircraft and wanted a debrief of the situation. I explained the events as above. When reviewing the write-up and Corrective Action with Maintenance; it was pointed out [to me] that [we] the flight crew [had] commented on the Number 1 Engine CON (Control) light - which I had not (I only mentioned the REVERSER light). When I read this before departure; I didn't catch the difference in the wording that Maintenance [had] described versus the condition I had initially described and had been dealing with for the past few hours. In the MEL; there is mention of a Maintenance Work Order. None of the details are presented to the flight crew. Upon arrival; Maintenance stated that per the Maintenance Manual (M/M) the REVERSER light may be illuminated; but the ENGINE CONTROL should not; and surmised that; that was what the miscommunication between Maintenance and Maintenance Control was about. This could have been prevented by a clearer communication line between Maintenance Control (ZZZ2); Local Maintenance; and the flight crew. In the MEL; as presented to the crew; there is mention of a Maintenance Procedure located in the Maintenance Manual; but it also is not very clear on the outcome of the setup as the flight crew may see things. In this example; MEL 78-1B states the Work Order to deactivate and secure the thrust reverser in the maintenance manual (MM); then continues to state that the ENG annunciation can be illuminated during Master Recall. But; it does not state what lights on the ENG panel are acceptable to have; or not have [illuminated]. The Maintenance Manual states that the REVERSER light is okay; while an EEC anomaly (ENGINE CONTROL) is not okay. It would be helpful if the MEL stated what non-normal lights are acceptable or not acceptable (in addition to the Annunciation Panel's Master Recall). Also; for completeness; it would be nice to know which C/Bs are involved per the Maintenance Manual procedure so that during preflight; it is easier to verify that all the correct C/Bs are collared (or closed); are indeed correct for the known situation.

Data retrieved from NASA's ASRS site 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.