I think one needs to consider some of the philosophy ...
- the aircraft is designed to meet a specific set of airworthiness and operational specifications and the TC attests to the design's compliance with such specifications
- the individual CofA carries the general TC approval forward to the individual aircraft
- the MR, likewise, carries the CofA approval to the day to day level of things
The basic presumption is that if a TC-related item is broken, the bird stays on the ground until the thing is fixed - otherwise the operation would involve a non-compliance with the Design Standards.
That's fine .. but totally unworkable and unreasonable in the real world.
Thus we have the idea of MMELs and resulting MELs.
The MMEL is the result of the stakeholders' looking at the effect of a problem on the aircraft's operation, specifically in respect of the problem's relationship with the Design Standards. If the think tank can come up with a set of restrictions which mitigate the risk associated with aircraft operation carrying the defective item (from a TC viewpoint), then operation with the defect, in accordance with the requirements of the MMEL, results in a situation similar to the fully serviceable aircraft from the point of view of redundancy, and so forth. These requirements ultimately find their way to the operator level via the MEL derived from the MMEL.
Hence
- INTENTIONAL operation with a defect involves a detailed consideration of the effect of that defect on the TC basis for the aircraft design. Necessary maintenance and operational restrictions to account for the defect while maintaining equivalent compliance with the Design Standard are built into the MMEL and, in turn, the MEL.
- CONTINUED operation with a defect occurring during the sector is concerned with recovering the aircraft to a safe landing and may involve a level of risk higher than that implicit in the Design Standard.
The despatch thing tries to put a line in the sand to define where intentional operation with a defect becomes continued operation and, naturally, there will be various approaches to this definition in the same way that there are variations in most things from one jurisdiction to another.
Consider though that, prior to takeoff, the pilot still has an option to get the bent bit fixed, even if the definition permits him/her to continue.
From a practical airmanship point of view, the pilot who mindlessly accepts a newly developed defect on the basis of QRH/AFM words alone, and without considering the MEL requirements, is acting a tad capriciously, I suggest.