Originally Posted by
kerflumexed
Most operators have a small group of mx experts that make the call on whether an item can be deferred, so maintenance signs off on it and then the plane can fly..
It's actually a little more involved than that. Not only does the dispatcher (and captain) also have a hand in determining what is/isn't able to be deferred, but either of those two folks can decline the aircraft (irrespective of MEL permissiveness) for a proposed flight if either feel it's warranted. It doesn't happen often, but it's an added procedural safeguard.