Much of today's training system development emphasizes lowering procurement and life-cycle costs. Also, there is a strong desire to evolve to truly mobile systems. At the same time, however, the services wish to retain the visual display performance previously achievable only with bulky dome or mirror systems. This paper addresses helmet-mounted display technology as an effective solution for the visual display requirements of tactical air crew training. The basic similarities that exist in the training requirements for both fixed wing and rotary wing tactical training systems will be discussed. This evaluation will also consider the variances in mission types, mission environments, mission equipment, crew configurations, and cockpit displays and the impact of these differences on training requirements. Subsequently, the paper will discuss the adaptability of the helmet-mounted display in meeting the training requirements. The possible physiological impact of the display's weight on the heads of flight crew members will be addressed as well as the perceived fragility of the display system. The impact of the display system on the facilities required to support the flight simulation system will also be considered. A final discussion of the trade-off of training requirements versus display system capabilities will be provided to demonstrate that the helmet-mounted system is an extremely cost-effective visual display for tactical air crew training.