Developing reliable and user-friendly in-flight aircraft measurements An EU initiative is facilitating important advances in optical measurements for in-flight testing of new aircraft designs. This will have a major impact on the development cost, time to market and safety of tomorrow's aeroplanes. Industrial Technologies © Thinkstock Aircraft certification standards are becoming increasingly stringent with demands for better safety data in shorter time intervals. The industry is turning to optical measurement systems over conventional heavy instrumentation to capture enormous quantities of data quickly for the aircraft certification process. With the EU-funded AIM2 (Advanced in-flight measurement techniques 2) project, scientists took the technology developed in the predecessor AIM project from the lab bench to industry to enable routine in-flight applications satisfying industrial demands. Lessons learnt in the AIM project were assessed and used for new measurement system designs. Based on this, a series of flight tests were conducted on multipurpose and business aircraft. This included wing deformation measurements through the image pattern correlation technique (IPCT), in-flight application of the advanced particle image velocimetry for flow field measurements, and the performance of IPCT propeller deformation measurements with a newly developed rotating camera. Yet more testing was performed on measurements for wing flow transition, wing deformation and landing gear movement. Better surface and strain measurements were recorded in lab and wind tunnel tests thanks to development of advanced sensors and a new data acquisition system. Flight tests using the LIDAR technique for air data calibration were carried out on a business aircraft. A dedicated advanced flight testing workshop targeting the flight testing community was held to introduce AIM2 measurement techniques and demonstrate their usefulness. Outcomes resulted in a handbook with information about such measurement techniques and guidance for novices to implement optical measurement techniques during flight tests. AIM2 further developed advanced in-flight measurement methods and several related tools that will now be more easily and routinely applied to flight, ground and large-scale testing. Keywords Optical measurements, in-flight testing, aircraft designs, aircraft certification, in-flight measurement
