Operational Applicability: ANO and JAR-OPS 1/3
CAA MMEL POLICY ITEM: GEN-1
22. "Dispatch": The point at which an aircraft first moves under its own power for the purpose of commencing a flight.
NOTE: The definition above is in accordance with that given in Article 129(2)(a) of the ANO.
The MEL applies to all defects that occur up to the point of dispatch, and comes into
effect again when the aircraft next comes to rest at the end of its flight. In the case of a helicopter which comes to rest without stopping rotors, it is deemed to have ended its flight and the provisions of the MEL then apply until it is next dispatched.
Once you have started taxiing, the MEL no longer applies. Common sense, however, should.