Directory of U.S. Military Rockets and Missiles|
Appendix 4: Undesignated Vehicles
|Copyright © 2004-2005 Andreas Parsch|
In 1996, Lockheed Martin participated in a DARPA program to demonstrate a micro air vehicle with no dimension larger than 15 cm (6 in). After the end of that program, the company continued to test-fly small UAVs of various sizes, and came to the conclusion that a surveillance UAV should not be too small. Below a wingspan of about 60 cm (2 ft), the vehicle gets too much tossed around by winds to be a stable observation platform.
With this background, Lockheed Martin answered to a U.S. Air Force request for information in 2001, where the USAF asked for suggestions for a very small man-portable reconnaissance UAV for their FPASS (Force Protection Airborne Surveillance System) requirement. Within the same year, the company demonstrated a small air vehicle, and in February 2002 a production contract was awarded. The first two complete FPASS systems (UAVs + ground equipment) were delivered in early July 2002.
The FPASS air vehicle, named Desert Hawk, is made of a mold-injected polypropylene foam, which looks very similar to styrofoam but is much more durable. It is powered by an electric motor driving a pusher propeller. The UAV is launched by two persons, who attach a bungee cord to it, extend the cord to about 100 m and then simply let the UAV go. After launch the Desert Hawk quickly rises to its operational altitude of about 150 m (500 ft). It can cruise for about one hour at a speed of up to 92 km/h (57 mph), and its operational radius is about 11 km (6 nm). The UAV is fitted with Kevlar skids on nose and tail and is recovered by a simple belly landing. The mission equipment, which can be either color cameras for day or infrared cameras for night-time surveillance, is located in the center fuselage and looks through a notch in the lower fuselage.
The Desert Hawk is equipped with a GPS receiver and flies its missions completely automatically, i.e. the operators do not have to control the aircraft and can fully concentrate on the real-time camera imagery. The video is also automatically stored by a tape recorder. The GPS waypoints for the flight path are preprogrammed using a ruggedized industry-standard laptop computer. The flight path can also be modified during the mission using the ground control station's data link. The UAV also has the capability to circle over a specified location and point its camera on that spot. Such a surveillance spot can be either preprogrammed or selected "on the fly" during a mission with a single keypress on the control computer.
Each FPASS system consists of six Desert Hawk air vehicles, the ground control station including the laptop computer, a viewing terminal and a field support kit. FPASS is already used operationally for perimeter surveillance of USAF installations in Iraq. Total Air Force requirement is for 21 FPASS systems, i.e. 126 Desert Hawk air vehicles.
Designation Note: The Desert Hawk is in operational service with the U.S. Air Force, but apparently has nevertheless not been allocated a formal aircraft designation. Mini-UAVs are to be designated as RQ-nn in the future.
Note: Data given by several sources show slight variations. Figures given below may therefore be inaccurate!
Data for Desert Hawk:
|Length||0.86 m (2 ft 10 in)|
|Wingspan||1.32 m (4 ft 4 in)|
|Weight||3.2 kg (7 lb)|
|Speed||92 km/h (57 mph)|
|Ceiling||300 m (1000 ft)|
 Eric Hehs: "Desert Hawk Mini UAV Goes Operational",
article in Code One Magazine, Vol. 18 No. 2 (April 2003)
 Jeanne Grimes: "Desert Hawk aids deployed members", AFMC News Service, July 2003
 "Unmanned Aircraft Systems Roadmap, 2005-2030", Office of the Secretary of Defense, August 2005
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