Models in the design of fuel systems

WHEN DEVELOPING SYSTEMS for a new aircraft, analytical and drawing techniques are used as far as possible to solve the various technical problems but there inevitably comes a point in the design where there is a need for assistance from some form of testing. The fuel system is no exception to this. Only in a very few minor cases can this work be delayed until the first aircraft is built; in the majority of cases the problems are of a fundamental nature which require a solution at an early stage in the design.