sentences:  This also implies that the air waybill should be issued immediately upon receipt of the goods and letter in instructions from the shipper.As long as the air waybill is neither dated nor signed twice, the goods do not fall within the terms of the conditions of the contract and therefore the carrier will not accept any responsibility for the goods.The validity of the air waybill and thus the contract of carriage expires upon delivery of the shipment to the consignee (or his authorized agent).