Date: 201402
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Light: Night
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight phase: Parked
Aircraft component: Fan Reverser
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Flying; First Officer
Human factors: Communication Breakdown; Confusion; Troubleshooting
Second reporter function: Pilot Not Flying; Captain
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: Pre-flight
Result: General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft; Human Factors; Logbook Entry; MEL
Primary problem: Human Factors

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.


Second narrative: After completing paperwork in Operations; I came out to the aircraft and Maintenance was working in the cockpit. I asked my First Officer what was wrong with the aircraft and he pointed to a Reverser light on the P5 Overhead Panel. We had flown this same B737-800 aircraft the day before and it had the Number One reverser deactivated and on MEL. The First Officer said he didn't remember the reverser light being 'On' the day before. I spoke to the Mechanic and he said they were going to reset the Reverser System to extinguish the light. Rereading the MEL; I saw no mention of the light; however it did say ENG (ENGINE) might be indicated on Master Recall. Four hours later; the Mechanic said the light was not a problem if it was 'On' and he handed me the logbook. The Mechanic had filled out the write-up portion and corrective action portion. I checked the overall completeness of the logbook page and while I thought something was not quite right I couldn't put my finger on it. After takeoff and while at cruise; we revisited the logbook page and became concerned that the Mechanic might have used an inappropriate description of the light which was 'On'; which was the reverser light. I was also concerned about the Mechanic filling out the write-up and not the First Officer.I was not concerned about this light issue. The [Reverser] System seemed to be MEL'd appropriately and I assumed the light being 'On' was just a nuisance. As the delay progressed; I became saturated with taking care of my passengers and crew. I just let Maintenance handle the situation. At the end I was frustrated by communication issues with Operations and Maintenance Control. When it came time to leave I couldn't believe we just took a four hour delay over a light which didn't matter anyway. I got 'let's go bias' big time. I didn't spend enough time really thinking about the logbook write-up and corrective action section. All the other sections looked good to me; so away we went. Looking back I should have taken a deep breath and taken the time to study the Logbook and talked it over with my First Officer.


Synopsis: 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.