In the PAHMIR (Preventive Aircraft and Health Monitoring) project pattern recognition and signal analysis is used to support and simplify the monitoring of complex aircraft systems. The parameters of the signal analysis need to be chosen specifically for the monitored system to get the best pattern recognition accuracy. An optimization process was developed that uses global heuristic search and optimization to find a good parameter set for the signal analysis. The computed parameters deliver slightly (one to three percent) better results than the ones found by hand. In addition it is shown that not a full set of data samples is needed. Genetic optimization showed the best performance.