A basic generic air force base has been created for AVAL within the R&D project "Värdering vapen och skydd, verkan, sårbarhet och risk". A large part of all the objects that the project handles are gathered on the generic air force base, from single soldiers to vehicles, ammunition storage and infrastructure at a system level. The air force base provides an example for application of different competences in vulnerability assessment on a common large system to assist the development of methods for handling large objects. Applying knowledge on different sub-systems on a large mutual system will enable testing of different scenarios with different possibilities for increased survivability. With the work presented in this report, a basic top level fault tree has been added to the air force base, together with some minor changes in damage criterias for certain targets in the air force base. In purpose of an initial validation of the top level fault tree, a simple mortar attack against the air force base has been simulated.