cauc0001: this is somewhat uncharted territory.
There are two things you need to keep in mind.
1) Some guidance is provided by the manufacturer in the MASTER-MEL (MMEL). As a pilot for an airline, you are not allowed to operate based on that guidance alone. MMEL is only a document from the factory, not for operational use.
2) Any airline must create its own AIRLINE-MEL, which is subject to approval by the local CAA. Usually, they take the MMEL from factory and fill small but necessary key information and guidance according to the airline's procedures and local CAA regulation.
If your AIRLINE-MEL says that dispatch with multiple defects is not allowed, you are not allowed to fly. Not only that, also the Maintenance Department is not allowed to release the aircraft to you!
--- some additional information, only as an example-------
Originally Posted by Airbus M-MEL year 2012
CRITERIA FOR DISPATCH
The decision of the Commander of the flight to have inoperative items corrected before the flight Will take precedence over the provisions contained in the MEL. The Commander may request requirements above the minimum listed, whenever in his judgment such added equipment is essential to the safety of a particular flight under the special condition prevailing at the time.
The MEL cannot take into account all multiple unserviceabilities. Therefore, before dispatching an aircraft with multiple MEL items inoperative, it must be assured that any interface or inter-relationship between inoperative items Will not result in a degradation in the level of safety and/or an undue increase in crew workload. It is particularly in this area of multiple discrepancies and especially discrepancies in related systems, that good judgment, based on the circumstances of the case, including climatic and en-route conditions, must be used.
Originally Posted by Some European Airline MEL
Before dispatching an aeroplane with multiple MEL/NEF items inoperative, it must be checked that any interface of inter-relationship between inoperative items will not result in degradation in the level of safety and/or an undue increase in crew workload. It is particularly in this area of multiple discrepancies and especially discrepancies hi related systems, that good judgment, based on the circumstances of the case including climatic and en-route conditions must be used.
In the event pilot in command and/or the respective maintenance staff have any doubt concerning the application of the MEL/NEF, contact XXX Airlines (XXX) MCC personnel via mobile phone or using any other communication. Taking into account all relevant factors XXX MCC personnel with co-ordination with Engineering Department will then release a recommendation to the pilot in command.
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What 3 problems with weight penalty did you have?