The MH-53J Weapon System Trainer/Mission Rehearsal System (MH-53J WST/MRS) was developed by the Aerospace Division of General Electric and delivered to the Air Force in 1990, During an initial assessment of system capabilities, it was used to support mission preparation for a joint 1550th Combat Crew Training Wing/U.S. Army Special Operations Forces training exercise that was then executed at White Sands Missile Range, NM. The exercise was designed to simulate a strike mission to recover critical avionics equipment from a remote research facility in a hostile third-world nation. An existing training database was enhanced to provide additional detail in the areas of operation for this exercise. This enhanced database was used for both crew rehearsals and development of products for inclusion in aircrew mission planning folders. Questionnaires were administered to aircrews at the conclusion of rehearsal and after completion of the mission. Crew reactions to this simulation-based rehearsal were very positive. These data were supplemented by direct observations of database enhancement, planning, and rehearsal activities and by extensive interviews with participating aircrews, planners, and intelligence personnel. This paper describes the MH-53J WST/MRS, the use of the device to support preparation for this joint training exercise, and an initial assessment of system capabilities to support rehearsal. It also discusses implications and lessons learned.