The Advanced Land Fire Control System (ALFCS) is an advanced technology demonstration project for the research and development branch of the Canadian Department of National Defence. ALFCS consists of a full-motion simulator of an Armoured Fighting Vehicle (AFV) turret, and a future Fire Control System (FCS). The ALFCS virtual environment includes a 6-DOF motion platform driven by sophisticated vehicle models and high-fidelity computer-generated visual and infrared imagery. The entire simulation system is re-configurable, facilitating investigations into a variety of alternate host vehicle configurations, and is capable of interfacing to other simulators. This four-year development project is being completed by a multi-disciplinary team, which includes a Human Factors Engineering (HFE) team. This paper outlines the Human Factors Engineering program which follows the guidance of Mil Std 46855 and the MANPRINT system. The resulting design support is comprised of Human Factors input in the areas of system and task analysis, function allocation, interface design support, crew station layout, human performance in simulation, usability testing, training system development, and AFV gunnery human performance evaluation trials. A unique and very successful aspect of this HFE program includes the extensive involvement of the AFV community from Canadian armoured units, which are involved in usability and human performance trials two to four times per year. One group of AFV crew participants is the "User Group", which is involved in design concept and usability trials twice per year, while the other group consists of "Active Tank Crews", who participate in extensive human performance Lab Evaluations. These Lab Evaluations require users to be fully trained in the future system and the simulation, and then participate in design study and operational scenarios to evaluate the simulation and the FCS using measures of task performance, usability, workload, and situational awareness. This paper describes the HFE program over the four-year development effort, and reports on progress and lessons learned through the first two years.