While computer powered military simulators get most of the media attention there is still a need for more mundane and less sexy mechanical simulators. For example, one of the more difficult jobs for crews of transport aircraft is learning how to efficiently handle cargo loading and unloading quickly (as in a combat zone or even under fire). Thus the U.S. Army and Air Force have long had ground based simulators what are basically parts of discarded aircraft with all the mechanical components used for loading and unloading cargo restored to working order so trainees (new recruits or veterans learning to use a new system) can safely and cheaply practice getting vehicles (combat and transport) safely loaded on and then quickly gotten off fixed wing or helicopter transports. These simulators are accurate enough to allow maintainers to practice their troubleshooting and repair skills without taking an actual aircraft out of service.
Simulators have also been built (some since the 1960s) so helicopters crews can practice loading or unloading personnel (including casualties) or equipment from hovering helicopters. Some simulators include weapons, so that operators can get used to operating machine-guns and autocannon from doors or side mounts on gunships. The validity of all these simulators is constantly tested as newly trained aircrew do the same jobs from an actual aircraft. If there are any flaws in the simulator setup they can be quickly detected and fixed.
Nevertheless computers are beginning to play a larger role in training for aircraft crews and aircraft maintainers. The new VR (Virtual Reality) computer equipment coming onto the commercial market (for entertainment) have shown themselves to use useful for some ground training tasks, particularly maintenance. Using an expensive (more so than the commercial stuff now available for gamers) VR headset a maintainer or crew member could go around a virtual aircraft and open panels and find or troubleshoot typical (or rare) problems. While not as accurate for loading and unloading practice a VR system would be useful for testing new designs or modifications of existing equipment.