Unmanned Systems Technology 013 | AutonomouStuff Lincoln MKZ | AI systems | Unmanned Underwater Vehicles | Cosworth AG2 UAV twin | AceCore Neo | Maintenance | IDEX 2017 Show report

74 Focus | Maintenance If there are documented issues with the comms then the system has to be ‘ramp checked’ by the delegated maintainer, often during a pre-flight connection test within the GCS. A primary task in such tests is a range check, in which an attenuator device reduces the power to the data link to simulate the power lost through the atmosphere as the UAV travels further from the GCS. The RSSI (received signal strength indicator) would then be checked, followed by the acknowledgement ratio. Any major discrepancies in data packets sent and received may warrant replacing an antenna, Ethernet cable or connector, quarantining the old hardware item before re-testing it and potentially dispatching it to the OEM. Ground-based issues tend to be easily resolved; onboard links, however, do not generally suffer issues unless there has been a hard landing or firmware conflict. It is therefore necessary to inspect the airframe for signs of a hard landing, ensuring firmware is up to date and that the profiles are correct for the GCS and UAV. Summary There is a long list of practices covering UAS checks, tests and fixes, and they are often inspired by the standards and practices of the manned aviation authorities. At the core of effective maintenance lies comprehensive and detailed data logging, which depends on the judicious upgrading of critical systems, particularly in firmware for avionics and vehicle health sensors. That means UAV technicians should be aware of two things. First, because firmware updates are rolled out at a high rate, they have been known to fix existing bugs while causing worse ones. Second, the sheer quantity of data from engine sensors and avionics should warrant greater use of data storage for UAS and automated scripts for analysis programs. This will allow maintenance software to communicate any trends or anomalies that technicians need to be made aware of, giving them more time to carry out complete pre-flight and post-flight checks, and ensure the safe operation and long life of their vehicles. Acknowledgements The author would like to thank Brad Hayden at Robotic Skies, Sean Greenwood and Shiju Devassey at Canadian UAVs, Jeff Ratcliffe at NWUAV, Steve Hayden at Kings Avionics, Justin Armer at Latitude Engineering, Professor Vaios Lappos at Cranfield University, and Linda Turner at Haiden Technology for their help with researching this article. April/May 2017 | Unmanned Systems Technology CANADA Canadian UAVs +1 403 796 5102 www.canadianuavs.ca OmniView Tech +1 855 741 8324 www.omniviewtech.ca Weatherhaven Global Resources +1 604 451 8900 www.weatherhaven.com DENMARK Scandinavian Avionics +45 79 50 80 00 www.scanav.com UAE Ultimate-UAV +971 4 39 22 105 www.ultimate-uav.com UK Cobham +44 (0)1202 882020 www.cobham.com Haiden Technology +44 (0)1246 866498 www.haiden.co.uk USA AECOM +1 213 593 8000 www.aecom.com Battlespace Flight Services +1 702 485 3695 www.battlespacefs.com Corridor Aviation Services Software +1 512 918 8900 www.corridor.aero General Atomics Aeronautical Systems +1 858 312 2810 www.ga-asi.com Latitude Engineering +1 520 792 2006 www.latitudeengineering.com NWUAV +1 503 434 6845 www.nwuav.com Pratt & Whitney +1 860 565 4321 www.pw.utc.com Kings Avionics +1 801 539 8412 www.kingsavionics.com Robotic Skies +1 505 289 0791 www.roboticskies.com ROV Systems +1 928 412 9995 www.rovsystems.net UAV Pro +1 434 292 4914 www.uavpro.com Examples of maintenance service providers