(1)
The carrier is not liable if he proves that he and his agents have taken all necessary measures to avoid the damage or that it was impossible for him or them to take such measures.
(2)
In the carriage of goods and luggage the carrier is not liable if he proves that the damage was occasioned by negligent pilotage or negligence in the handling of the aircraft or in navigation and that, in all other respects, he and his agents have taken all necessary measures to avoid the damage.