VX-31 Scan Eagle UAVs awaiting transport to the catapult launch system prior to flight test event at NAWS China Lake
(U.S. Navy Photo)
VX-31 Raven B UAV performs a manually operated fly-by integrity check on the NAWS China Lake Land Ranges.
(U.S. Navy Photo)
VX-31 Dakota on display on the NAWS China Lake UAS airstrip as the sun sets over the majestic Sierra Nevada mountains.
(U.S. Navy Photo)
The Scan Eagle unmanned air vehicle was designed for long endurance capability. Scan Eagle features a high aspect ratio swept wing, shoulder-mounted on a cylindrical fuselage using blended fairings. The air vehicle is tailless, with a rear-mounted engine driving a pusher propeller. The structure is carbon fiber composite with fiberglass winglets. Two sets of elevons on the wings provide pitch and roll control, with rudders on the winglets at the wingtips for directional control.
The Super Wedge catapult provides the initial velocity and rate of climb.
The catapult requires approximately 45-75 PSI compressed air (depending on weight and wind) to charge the system. The pneumatic catapult is charged from a remotely operated air compressor attached to the launcher.
The patented Sky Hook retrieval system captures the air vehicle, providing runway-independent recovery. The Sky Hook system includes a differential GPS receiver and antenna, which the air vehicle uses to make an accurate approach via data relayed through the control station. The air vehicle is snagged by flying into a rope suspended from approximately 45 feet (14 m) above the surface. A hook on the wingtip catches the line and quickly stops the air vehicle. When the air vehicle senses the accelerations due to rope capture, the engine automatically shuts off. If the air vehicle misses, it automatically goes around on a clear path and makes another approach when commanded. Scan Eagle is capable of a belly landing in an emergency recovery situation.
The Scan Eagle ground control station (GCS) consists of the data link antennas and an operator's station running the software on a standard PC using the Microsoft Windows XP operating system. The Scan Eagle ground software includes operators’ consoles for preflight checks, operations, flight, and capable of monitoring of multiple air vehicles on independent missions, as well as simulating flight operations to facilitate training and mission planning. Software provided with Scan Eagle includes I-MUSE, FlightSim, and Object Tracker and utility code for each programmable element of the system.
The most common payload is an inertial-stabilized camera turret that allows for the tracking of a target of interest for extended periods of time. The VX-31 Scan Eagle is also being used for enhancing special payload capabilities and developing the capability to provide real-time targeting. The Scan Eagle has also provided Bomb Damage Assessment in recent missile tests conducted at China Lake Ranges.
The Raven B system, an enhanced version of the battle proven Raven A system, is a lightweight solution designed for rapid deployment and high mobility for both military and commercial applications requiring low altitude surveillance and reconnaissance intelligence. The most advanced small unmanned aerial system (SUAS) deployed with the U.S. Armed Forces, the Raven can be operated manually or programmed for autonomous operation, utilizing the system’s advanced avionics and precise GPS navigation. With a wingspan of 4.5 feet and a weight of 4.2 pounds, the hand-launched Raven provides aerial observation, day or night, at line-of-sight ranges up to 10 kilometers. The Raven delivers real-time color or infrared imagery to the ground control and remote viewing stations.
The avionics and control system is made up of navigation and system health sensors, RF data link components and electromechanical control devices.
A central processing unit runs software that performs autonomous functions, responds to command and control received from the GCS and transmits data back to the GCS. A high level automatic flight control system is executed in the avionics software. The air vehicle can fly in five different modes: manual mode provides full control over the aircraft flight path; altitude mode allows for a set altitude while maintaining full lateral control; home mode commands the aircraft to return to the home waypoint; loiter mode commands the aircraft to circle a selected location; navigation mode directs the flight path through a pre-programmed set of waypoints.
The Dakota is an SUAS originally developed by Daedalus Research Inc. as the “Truck” general-purpose reconnaissance/surveillance UAV. This platform first flew in August 1994 and by late 1997 several systems had been developed for demonstration purposes. Two of the early prototype systems were acquired by the U.S. Navy’s Naval Research Laboratory (NRL) for use in development of unique UAV technologies. In July of 2001, Geneva Aerospace acquired design rights to the Dakota and has continued to refine the overall UAV into a complete and fairly robust UAS.
The external shape of the Dakota is similar in design to a conventional general utility aircraft. The fuselage of this vehicle is a simple tapered box-section design with a high-mounted constant chord wing (40 dihedral) and conventional tail surfaces. The UAS is powered by a 22 hp. 3W-240iB2TS flat-twin two-stroke gasoline engine equipped with a two-blade propeller. The landing gear is a fixed tricycle type gear with nose wheel steering for conventional hard surface takeoff and landing. Dakota’s overall wingspan is 15.17 ft. and the empty weight of the aircraft is 160 lbs.
The aircraft is capable of achieving airspeeds of 98 KTS and max endurance is rated at 6 hours with a service ceiling of 15,000 ft. MSL. With a max gross take off weight of 240 lbs and payload capacity of approximately 40 lbs, the Dakota was acquired for flight testing miniature weapons systems and developmental sensors payloads.
Last Update 06-Sep-2013 9:55