This report discusses whether data registered in virtual air combat simulations at the Swedish Air Combat Simulation Centre (FLSC) can be used for combat assessments in models at theatre level. Data registered in 75 simulations at the FLSC was analysed to determine whether any information about the desired relationships between parameters could be extracted. Since the simulations analysed were conducted for the purpose of training air squadrons, the input parameters were not varied in a balanced way and many background factors were not documented. However, even if the data is not sufficient for making assessments at higher levels, estimated values of the number of fighters shot down, duration times and fuel consumption can be used. The design of simulations specifically aimed at producing data required for assessments at theatre level is discussed in the report. The work presented was done in partial fulfilment of the requirements for the Degree of MSc in Military Operational Research at the Royal Military College of Science (RMCS), University of Cranfield.