This past month, the US Army has officially began its search to find replacement “Block III” engines for its second generation RQ-7B Shadow UAV (RQ-7Bv2) aircraft. The initial RQ-7Bv2 scout planes entered service just last year, but new mission equipment is already weighing down the planes immensely. To put this extra weight into perspective, the RQ-7B was designed to have an overall takeoff weight of 280 lbs, but after adding all the necessary equipment and mission modifications, the takeoff weight balloons to 460 lbs. This takeoff weight is especially troublesome considering that the US Army will likely make even more changes to the aircraft equipment.
The RQ-7Bv2 is an unmanned aircraft used for a variety of tasks including target acquisition, reconnaissance missions, and surveillance operations. Usually, the RQ-7B is paired with an AH-64 Apache gunship for scouting purposes so as to survey the battlefield without ever sending in a manned aircraft. The latest generation of RQ-7B features a bevy of upgrade compared to its predecessor including a larger wing-span, higher fuel capacity, more aerodynamic design, and improved relay avionics.
All improvements considered, the RQ-7Bv2 has a flight endurance of nearly 9 hours, however, current RQ-78 engines fail too often to be considered reliable. The US Army has addressed this concern on several occasions, and they have expressed that the next set of engines must have a failure rate of no less than once every 1,000 flight hours.
“This propulsion system shall provide RQ-7Bv2 with a more reliable and lower life cycle cost system. The system shall allow growth in aircraft weight while maintaining performance.”
Over the next two years, the US Army will test two competing engine designs before making their final decision on which company will be awarded the “Block III” engine contract. Production on the “Block III” engines will likely begin towards the latter part of 2017, and the US Army expects all engines to be completed and installed by 2019.