There are many sources of carbon monoxide (CO) leakage into the cabin of General Aviation (GA) aircraft. Exposure to CO, which is part of the engine exhaust in GA aircraft, can impede the pilot’s ability to direct the airplane which may lead to accidents. In order to prevent accidents, an electrochemical CO detector can be used to alert the pilot to the presence of CO. The objective of this study was to determine the best location for CO detector placement in GA aircraft. Early CO detection as well as visibility and accessibility of the detector were some of the parameters involved in determining the optimum CO detector location. Considering these issues, five detector placement locations were considered: visor, instrument panel, leg area of front seats (left and right sides), and rear seat. Field tests to monitor CO levels during GA flights were conducted at Kansas State University at Salina using data logging CO detectors. The results from these measurements have been categorized according to several different variables and then analyzed statistically. Measurements taken so far during the summer and early fall indicate that the majority of CO exposure events occurred on the ground before take-off. During such ground-based CO exposure events, the timing was consistent with open windows allowing exhaust fumes to enter the cockpit area. This paper will also discuss the results of additional measurements taken during the winter months when other modes of CO exposure may be involved.