Narrative:

The flight crew called with a discrepancy on a log page. That discrepancy read: 'while at cruise flight received GPWS fail; terrain fail and windshear fail status messages. Placarded and placed on MEL'. The messages stayed annunciated for some time. I contemplated pulling the circuit breaker (circuit breaker) for the GPWS thinking that the messages could be distracting to the flight crew. They told me that was not necessary as the messages weren't flashing; they just came on and stayed on. I elected to MEL the entire GPWS.when that is done we use MEL 34-42-01-00. That [MEL] reference has no stated weather (wx) restrictions; no required (M) action and states that the flight crew is to 'assume loss of GPWS mode 1 thru 6 aurals. It [MEL] doesn't direct that these modes be placed on MEL separately and maintenance computer doesn't link to additional MEL's. No maintenance action was taken and from my point of view the entire GPWS was on MEL at that time with no other maintenance action required.the MEL process was in place and the dispatcher on duty at that time was contacted in a three-way conversation. There was no mention of additional operational requirements at the time of the three-way conversation but I dropped off; the dispatcher was briefing the crew on MEL changes to the dispatch release and operational requirements. I believe that there was a dispatcher shift change around this time. I was scheduled to leave at the time a dispatcher stated that the MEL needed to be repaired due to weather restrictions. That was a surprise to me. Apparently; if the MEL 34-42-01-5 is used (windshear mode) there is a statement that says: c) takeoffs and landings are not conducted in known or forecast windshear conditions.' apparently those conditions existed in ZZZ two flights after the original MEL.it makes sense that if windshear [mode] is out; this should be a requirement. However; if the entire system is out doesn't it make sense that the windshear is out? In that case shouldn't any additional requirements for any or all of the sub-paragraphs of the MEL to be implemented if these are out? What if I had elected to pull the circuit breaker? Or if the circuit breaker had been popped? Then we know that windshear and all other functions would have been out. In addition there is a required (M) action for the windshear. Shouldn't that have been a requirement of the MEL for the entire system? Shouldn't we add all concerns comments; O; cm; M actions from the sub-paragraphs if we place the entire GPWS on MEL?I suggest clean up the MEL in question; please. The oncoming dispatcher stopped the aircraft due to weather restrictions that weren't clear in the MEL.

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Original NASA ASRS Text

Title: A Maintenance Controller describes about the possibility of misinterpreting his company's CRJ-200 MEL Chapter 34 language when deferring the entire GPWS system. The lack of any MEL (O); (CM) or (M) 'actions' may give the impression that deferring the entire GPWS system would appear to be less restrictive than an individual sub-section deferral would have required.

Narrative: The flight crew called with a discrepancy on a log page. That discrepancy read: 'While at cruise flight received GPWS fail; terrain fail and windshear fail status messages. Placarded and placed on MEL'. The messages stayed annunciated for some time. I contemplated pulling the circuit breaker (CB) for the GPWS thinking that the messages could be distracting to the flight crew. They told me that was not necessary as the messages weren't flashing; they just came on and stayed on. I elected to MEL the entire GPWS.When that is done we use MEL 34-42-01-00. That [MEL] reference has no stated weather (wx) restrictions; no required (M) action and states that the flight crew is to 'assume loss of GPWS Mode 1 thru 6 aurals. It [MEL] doesn't direct that these Modes be placed on MEL separately and maintenance computer doesn't link to additional MEL's. No maintenance action was taken and from my point of view the entire GPWS was on MEL at that time with no other maintenance action required.The MEL process was in place and the Dispatcher on duty at that time was contacted in a three-way conversation. There was no mention of additional operational requirements at the time of the three-way conversation but I dropped off; the Dispatcher was briefing the crew on MEL changes to the Dispatch Release and Operational Requirements. I believe that there was a Dispatcher shift change around this time. I was scheduled to leave at the time a Dispatcher stated that the MEL needed to be repaired due to weather restrictions. That was a surprise to me. Apparently; if the MEL 34-42-01-5 is used (windshear mode) there is a statement that says: c) Takeoffs and landings are not conducted in known or forecast windshear conditions.' Apparently those conditions existed in ZZZ two flights after the original MEL.It makes sense that if windshear [mode] is out; this should be a requirement. However; if the entire system is out doesn't it make sense that the windshear is out? In that case shouldn't any additional requirements for any or all of the sub-paragraphs of the MEL to be implemented if these are out? What if I had elected to pull the CB? Or if the CB had been popped? Then we know that windshear and all other functions would have been out. In addition there is a required (M) action for the windshear. Shouldn't that have been a requirement of the MEL for the entire system? Shouldn't we add all concerns comments; O; CM; M actions from the sub-paragraphs if we place the entire GPWS on MEL?I suggest clean up the MEL in question; please. The oncoming Dispatcher stopped the aircraft due to weather restrictions that weren't clear in the MEL.

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.