(3)The period of the carriage by air does not extend to any carriage by land, by sea or by river performed outside an aerodrome. If, however, such a carriage takes place in the performance of a contract for carriage by air, for the purpose of loading, delivery or transshipment, any damage is presumed, subject to proof to the contrary, to have been the result of an event which took place during the carriage by air.
