Crown Agents serves as purchasing agent for roughly 90 countries and 350 principals. Though it shipped only 1% by air of that which it transported by sea in 1975, it is probably atypical due to the wide range of materials handled. The evolution of its air cargo business is traced over the last four decades, including changes from scheduled to charter flights, disaster aid, and the requirements of. landlocked countries (whose port facilities are not controllable). Air cargo is often found to be the most cost effective means of shipping.