The Netherlands Armed Forces operate several types of helicopters, such as Chinook, Apache, Cougar, Lynx, and in the future NH90 helicopters. To gain insight on the impact of helicopter missions on the life of the helicopter's airframe, helicopter's engine, and other vehicle systems, large amounts of flight data, health data and usage data of the helicopters have to be collected, stored and analyzed. This paper presents the advantages of using an XML Database for storing and querying the collected heterogeneous helicopter signal data.