B737 flight crew reported that with the lower multi-function display unit deferred; all engine instr...

Narrative:

Dispatched with a placard; MEL XXXX; for the lower multi function display unit inoperative. Placard was authorized on the previous day. Checked and complied with the MEL before departure. Specifically; we verified that the engine indications could be manually selected to either the captains or fos inboard display unit and that all other display units were operative. Even though we complied with the MEL before departure; during cruise the first officer and I had further discussion about the MEL verbiage and the indications that we were able to see. Specifically; we were able to see all engine indications compacted on the upper mfd but were not able to view hydraulic quantity and pressure. Earlier; we initially dismissed not seeing this as a condition of the MEL placard but we increasingly thought that this didn't make sense. Decided to send a message for maintenance to meet the aircraft upon arrival and followed up with a radio request to maintenance to discuss the MEL placard. Made the following aircraft maintenance log entry: with current placard for lower display unit inoperative unable to view hydraulic quantity and pressure. Discussed entry with maintenance and briefed oncoming crew.possibly an additional unaddressed system display indication failure. If this is true; it would have been better if it was caught sooner by the flight crew or maintenance. MEL addresses being able to see engine indications but doesn't address system indications.

Original NASA ASRS Text

Title: B737 flight crew reported that with the Lower Multi-Function Display Unit deferred; all engine instruments were displayed except for hydraulic quantity and pressure on the Upper Display Unit.

Narrative: Dispatched with a placard; MEL XXXX; for the lower Multi Function Display Unit inoperative. Placard was authorized on the previous day. Checked and complied with the MEL before departure. Specifically; we verified that the engine indications could be manually selected to either the Captains or FOs inboard display unit and that all other display units were operative. Even though we complied with the MEL before departure; during cruise the FO and I had further discussion about the MEL verbiage and the indications that we were able to see. Specifically; we were able to see all engine indications compacted on the upper MFD but were not able to view hydraulic quantity and pressure. Earlier; we initially dismissed not seeing this as a condition of the MEL placard but we increasingly thought that this didn't make sense. Decided to send a message for Maintenance to meet the aircraft upon arrival and followed up with a radio request to Maintenance to discuss the MEL placard. Made the following Aircraft Maintenance Log entry: With current placard for lower display unit inoperative unable to view hydraulic quantity and pressure. Discussed entry with Maintenance and briefed oncoming crew.Possibly an additional unaddressed system display indication failure. If this is true; it would have been better if it was caught sooner by the Flight Crew or maintenance. MEL addresses being able to see engine indications but doesn't address system indications.

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.

Attributes
ACN	1485869
Time
Date	201710
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	EICAS/EAD/ECAM
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Type 2656
Person 2
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural MEL

B737 flight crew reported that with the lower multi-function display unit deferred; all engine instruments were displayed except for hydraulic quantity and pressure on the upper display unit.