With the increased sophistication and capability of modern combat aircraft, the task of the front-line pilot has never been more demanding. The complexity of modern aircraft, their systems and their capabilities, dictates an excellent standard of training before these capabilities can be properly exploited. However, this very complexity leads to it being very expensive to carry out extensive flying in a training mode. There are ground-based alternatives ranging from Computer-Based Training (CBT) to Full Mission Simulation (FMS). In addition there is the availability of aircraft that are less costly to operate than the front-line types but are capable of training for them. Such more economical aircraft can use techniques such as "embedded training" where the weapons and systems of the front-line are copied or simulated. So-called "on-the-job" training in the front-line aircraft is simply too expensive when viable alternatives exist.