MDHS has been performing virtual prototyping (VP) simulation for a number of years in support of the Longbow Apache(TM) (LBA) as well as other system development activities. Recently we have performed a virtual prototype simulation for a new combat system not integral to the Longbow using our Engineering Development Simulator(EDS). The Longbow Apache(TM) Engineering Development Simulator provides the means to accomplish virtual prototyping for not only Apache enhancements but also for other combat systems which interface directly with the Longbow Apache(TM) or other Army aviation platforms. This paper will address potential applications of VP environments as well as recent MDHS activities in conducting VP based analysis. This presentation will outline the Precision Guided Rocket System's use of the Longbow Apache(TM) Engineering Development Simulator to verify weapon fightability, employment techniques and overall rocket system effectiveness, when used by LBA aircrews.