The aviation industry is extremely safety conscious in all its operations and the supply of aviation fuel is no exception. Great care is taken to ensure that clean, dry and on-specification fuel is supplied to aircraft safely and efficiently at all locations around the world. The quality control system is based on the principle that aviation fuel is clean, dry and on-specification following manufacture at the refinery. The distribution system from refinery to airport is designed to minimise the chance of contamination with dirt, water or other fuels so that the aviation fuel remains on-specification. Where contamination with other products could occur (for example in multi-product pipelines or on multi-product tankers), contamination-sensitive properties are always laboratory tested to confirm that no contamination has occurred. If product traceability is lost and contamination cannot be checked in this way, a complete specification analysis must be performed. At airports there are dedicated facilities for each grade of aviation fuel to avoid any contamination with other fuels. The presence of dirt and water in the fuel is minimised by the combined use of product setting, microfilters, and filter water separators throughout the distribution system. At the final stage of delivery into plane, fail-safe filter monitors may be used to prevent the passage of dirt and free water. Shell companies were among the first to introduce this equipment on all their refuelling vehicles. In addition to this emphasis on quality, it is essential to ensure that fuel is always delivered into the aircraft safely and efficiently. With the need to minimise aircraft turn-round times, high fuelling rates are required: a typical Boeing 747 uplift of 150 tonnes, for instance, needs to be delivered at flow rates of up to 6.5 tonnes/minute. Any system failure could thus have disastrous results, and comprehensive procedures are enforced at each airport to ensure that hoses, pressure controllers and other components are regularly tested. Detailed records are kept of all fuel and equipment test results. The system is designed so that the history of any batch of fuel delivered into any aircraft anywhere in the world can be traced back to the original refinery, (including all equipment used to handle the fuel, when the equipment was tested, laboratory results, etc). To ensure compliance with all these international requirements, all airports are inspected at frequent intervals. Outside North America, oil companies generally own the airport storage and hydrant systems and contract with an airline to supply into plane, following the strict operational guidelines described earlier. In the USA and Canada the situation is very different. There, airlines - often in a consortium - generally own the fuel facilities which are operated on a contract basis by a specialist company. This fuelling contractor undertakes a number of additional tasks associated with into-plane fuelling - eg. operating switches and valves on the aircraft's fuelling panel. Outside North America, these tasks have hitherto been carried out by airline staff, but some airlines are now requiring them to be conducted by the fuel suppliers. These services incur greater costs and liabilities, factors which need to be taken into consideration in the fuel supply contracts. This is an extract from `Fuelling aviation', copies of which can be obtained from Group Public Affairs, Shell international Petroleum Company Limited.
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