Automation is generally embarked upon with the idea of improving the economics of some process, largely by reducing the manpower, but it may be used also as means of solving computations which would otherwise present an almost impossible task for ordinary human effort, or involve so many people that this also would entail problems of organization. It may be difficult to demonstrate that automation of aircraft navigation can cheapen the job by saving in manpower, but it can be seen that the same manpower can be provided with solutions to navigation problems which will improve the aircraft navigational capability, but which would otherwise have demanded more crew. Processing the data obtained from a navigation satellite might be so complicated as to be beyond the scope of what can be expected of human effort in an aircraft, and even if this is possible the time taken to compute the fix may make the information so out of date as to be of little practical value. It is quite certain that by introducing automation into aircraft navigation, the flight crew can be relieved of some tasks so that, particularly in respect of the captain, more time can be made available for the management of the aircraft. We are, in fact, dealing with the question of workload and, therefore, we must look at the size of the job and the time available to do it.