Which MEL categories would ground a commercial airliner if they're inoperative? Which Minimum Equipment List (MEL) categories would require a commercial airliner to be grounded (Aircraft On Ground or AOG) if they're inoperative? For example, any category A MEL item is considered an AOG item; is it the same for category B items?
If a piece of inop equipment CAN be deferred using the MEL, then the aircraft isn't grounded. When there is no MEL relief &amp; the part has to be changed out is when you have an AOG scenario.