New system fits the bill

In order to undertake trials for the TP400 power-plant for the Airbus Military A400M transport aircraft using data acquisition, airborne data recording and visualisation systems to collect, distribute and process the power-plant data, Marshall Aerospace used commercial off-the-shelf products provided by sub-system design and manufacturing solutions provider, Curtiss-Wright Controls Avionics & Electronics (CWC-AE). The solution was compact enough to fit in the wings of the aircraft, reducing wiring and testing costs. Marshall Aerospace instrumented a C-130 with seven Data Acquisition Units (DAUs) to evaluate the performance, stability and operability of the power-plant. The DAUs acquired sensor data and distributed it to onboard computers and a recorder via an Ethernet switch. In 116 hours of engine running time the Flight Test Instrumentation (FTI) team measured, recorded and processed over 3,000 parameters. The compact PCM/Ethernet system resulted in the reduction of flight test instrumentation costs as the commercial off-the-shelf (COTS) hardware was used for both flight and ground testing. “Curtiss-Wright equipment enabled Marshall Aerospace to continuously meet or exceed changing customer requirements,” begins Ben Jakubowski, senior flight test instrumentation engineer at Marshall Aerospace. An Ethernet first Even though Marshall Aerospace is a long time user of the Acra KAM-500, it was its first time developing a system that output Ethernet packets. It enabled fast configuration changes and data rates that would have been unachievable with a traditional PCM system. CWC-AE provided the hardware and integration services, 24-hour phone and 48-hour in-person support and two weeks of system training to Marshall Aerospace's entire flight test group to help them familiarise with the Ethernet system architecture and software. Seven Acra KAM-500 DAUs with 13 user slots each were on board the C-130. Each DAU was configured with a spare slot or two to ease system upgrades and modifications and were mounted in rugged boxes with double density connectors. Three of the DAUs were located in the cabin of the aircraft to monitor acceleration and strain while outputting Ethernet data. Three more were located in the wing in a master slave configuration where the master output Ethernet data and the slaves fed the master with PCM data. An additional Acra KAM-500 was placed in the wing to monitor the pressure data for engine intake distortion measurements and output Ethernet data. A 1Gbps managed Ethernet switch distributed the acquired data to dual on board computers and a data recorder completing the data recording and visualisation system. The flight engineer used a laptop running GS Works on the flight deck to perform flight flutter assessments utilising the software's ability to view, pause and filter captured data. The data recorder stored data acquired from the Acra KAM-500 DAS and the AFDX buses for post-flight playback and analysis on the ground. Do the math All along this high risk programme, the Flight Test team utilised mathematical modelling and simulation data to mitigate risks and plan a safe and efficient Flight Test programme. Thanks to meticulous planning and use of the flight simulator, the project was executed safely and successfully, gathering all of the extensive data required by the customer. On board performance monitoring and analysis was a key component. The FTI team successfully measured, recorded and processed approximately 1,000 parameters. CWC-AE equipment allows Marshall Aerospace to run simultaneous flight test programmes thanks to its inherent flexibility. Since the hardware is not programme specific, the hardware will continue to help Marshall Aerospace satisfying customer needs for reliable flight test data. www.cwc-ae.com