Originally Posted by
Mad (Flt) Scientist
There's absolutely no guarantee of that, without knowing precisely what the RTOW penalty is intended to achieve for each case. If all three defects have an impact on climb capability, then they may well be additive and you'd need to combine the penalties.
But in the case of the original question, it's easy. The MEL says no multiple defects are allowed. End of.
What he said.
It does seem somewhat unusual for only one defect per airframe to be allowable, as this would increase the likelihood of an AOG situation considerably. It could be that the requirements are worded/translated(?) in a strange manner as a conventional MEL/DDG will normally have conditions against some defects which require normal operation of other systems but allow multiple defects. I agree that with lack of relevant guidance, performance defects should be considered additive.
As an aside, it’s always a good idea to stop for a think when carrying multiple defects: given the vast array of combinations, it’s quite possible that you might be the first person to have encountered/considered such a mix...