There is a document for every aeroplane called the Minimum Equipment List (MEL). It is in fact an extremely thick book. This is approved by the manufacturer and details defects to the aeroplane and the implications regarding dispatch. Some defects prevent dispatch. Some defects can be dispatched with provided there is some maintenance action. Some defects can be dispatched with no action. All have time limits on the repair, ranging from "before the next flight" to an unlimited period, provided the defect is regularly inspected. If an item
is not included in the MEL, you
cannot dispatch. Two extremes for you:
You cannot dispatch with an engine unserviceable. Hopefully, that's self evident.
You can dispatch with a landing light unserviceable.
Would you really want to cancel a flight for a failed landing light bulb when there are plenty of other lights you can use instead?
Sounds like the usual journo fishing.
