It is important to investigate the threat posed to commercial aircraft by on board electronic transmitters in the passenger cabin and the cargo holds of large transport aircraft. These transmitters may be in the form of unintentional use of portable electronic devices or even intentional radio frequency (RF) threat sources from terrorists. Thus, it is of interest to determine the "interference path loss" (IPL) from a transmitting device inside the cabin of such aircraft to the antenna terminals of a potential victim system of the aircraft. Past studies have concentrated on measurements. These efforts to measure IPL directly have demonstrated that accurate and repeatible measurements are difficult to obtain. Very little modeling work has been done successfully to understand the IPL on aircraft. In this thesis, we propose a 3-step methodology to quantify the interference path loss (IPL). We then apply this methodology to a broad class of aircraft and show results. To validate our results, we compare our findings to known measurements and discuss possible sources of errors. Finally we suggest areas of improvement to our analysis and propose future work. / Master of Science