v1.6.0 / chapter 9 of 19 / 01 mar 10 / greg goebel / public domain
* This chapter completes the discussion of US battlefield UAVs by describing systems that have seen relatively limited service, or are currently experimental.
* In the 1980s, Ryan followed up on its long history of robot aircraft development with two jet-propelled UAVs for tactical reconnaissance and other roles, designated the "Model 324 Scarab" and the "Model 350 / BQM-145A".
The Scarab is a medium-range reconnaissance asset, similar in operational
concept to the old Ryan FireFly UAVs, but implemented with improved
technology. It was designed to Egyptian Air Force requirements and was first
flown in 1988. 56 were delivered and the type remains in service at last
notice. It is a neat UAV with low-midbody-mounted swept wings, a twin-fin
tail, and a rear-mounted Teledyne CAE 373-8C turbojet engine with the intake
on the rear spine of the UAV.
RYAN MODEL 324 SCARAB:
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spec metric english
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wingspan 3.35 meters 11 feet
length 6.12 meters 20 feet 1 inch
max loaded weight 1,130 kilograms 2,500 pounds
maximum speed 970 KPH 600 MPH / 520 KT
service ceiling 13,100 meters 43,000 feet
range 2,250 kilometers 1,400 MI / 1,220 NM
launch scheme RATO launch.
recovery scheme Parachute recovery.
payload Reconnaissance cameras.
guidance system Programmable with radio control backup.
_____________________ _________________ _______________________
The Model 350 / BQM-145A was developed in the early 1990s for a joint US Navy
/ Marine Corps and Air Force "Medium Range UAV" program, with the Navy
developing the airframe and the Air Force providing the payload. The
BQM-145A was designed to precede air strike packages into a target area and
relay reconnaissance information in real time.
Production BQM-145As were to have a metal airframe, but the initial two prototypes were built with plastic composites, with initial flight in May 1992. The program then collapsed in 1993 due to technical difficulties and funding cutbacks. However, six BQM-145As with plastic-composite airframes then under construction were completed, with first flight of a composite BQM-145A in 1997.
Apparently Northrop Grumman continued to use them for other experiments. Some sources claim they have been evaluated for unmanned strike missions, and paintings have been circulated showing a BQM-145A fitted with a "high-power microwave (HPM)" generator in the nose to fry adversary electronic equipment. It has been confirmed that BQM-145As have been flown in the US on test flights carrying HPM payloads.
The BQM-145A has some broad similarities to the Scarab, with a similar
configuration except that it has twin air intakes on either side of the
fuselage, forward of the wing roots. Like the Scarab, it has no landing
gear. It is powered by a Teledyne CAE 382-10C (F408-CA-400) turbojet engine,
with 4.4 kN (455 kgp / 1000 lbf) thrust. It can be air-launched from a
standard fighter such as the F-16 Falcon or the F/A-18 Hornet.
RYAN BQM-145A:
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spec metric english
_____________________ _________________ _______________________
wingspan 3.2 meters 10 feet 6 inches
length 5.6 meters 18 feet 4 inches
payload weight 135 kilograms 300 pounds
launch weight 900 kilograms 2,000 pounds
speed 1,115 KPH 690 MPH / 600 KT
ceiling 12,200 meters 40,000 feet
range 1,300 kilometers 810 MI / 705 NMI
launch scheme RATO or aircraft launch.
recovery scheme Parachute or parafoil.
payload Reconnaissance or other payload.
guidance system Programmable with GPS-INS & radio control.
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BACK_TO_TOP
* In 2003, Aurora Flight Sciences, which has developed a number of research UAVs for NASA that are discussed, unveiled the "GoldenEye" series of UAVs, built under a DARPA contract and apparently focused on covert or special forces operations. The GoldenEyes are "tailsitter" or "pogo" machines that take off and land straight up. They are barrel-looking machines with landing gear on the bottom of the "barrel, and a wing that pivots, allowing it to be aligned with the aircraft centerline in cruise flight and at a right angle to the centerline in hover flight.
The initial variant was the "GoldenEye 100". The GoldenEye 100 is built of
graphite and fiberglass composites, and has low radar, infrared, and acoustic
signatures. It is powered by a 28 KW (38 HP) Wankel rotary engine from UAV
Engines LTD in the UK. The GoldenEye 100 has an autonomous flight control
system with GPS-INS navigation.
AURORA GOLDENEYE 100:
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spec metric english
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wingspan 3.0 meters 10 feet
height 1.7 meters 5 feet 6 inches
duct diameter 90 centimeters 3 feet
empty weight 48 kilograms 105 pounds
max loaded weight 68 kilograms 150 pounds
maximum speed 295 KPH 185 MPH / 160 KT
hover endurance 1 hour
cruise endurance 4 hours
cruise range 1,000 kilometers 620 MI / 540 NMI
_____________________ _________________ _______________________
The GoldenEye 100 can carry a small electro-optic sensor turret or other
payload and features a radio datalink. Apparently the DARPA specification
mysteriously required that it be able to carry "two coke-can size payloads"
for which no details were released.
Aurora also developed "GoldenEye 50" and "GoldenEye 80" variants. The DARPA program was terminated with no planned follow-on, but Aurora has continued development, with current focus apparently on the GoldenEye 80, with an improved variant in the works.
* In addition, AeroVironment has developed a pogo UAV named the "SkyTote" under an Air Force contract. It is described as a demonstrator for a vehicle intended for the precision delivery and pickup of "cargoes", a description that covers an extremely wide range of actual applications. Details are unclear, but illustrations of the SkyTote show it to be another pogo-type tailsitter, with a surprising resemblance to the pogo fighters of the 1950s. It is powered by a Wankel rotary engine.
BAE Systems developed a demonstrator UAV similar to the GoldenEye, named the "AirWolf", as part of a DARPA experiment in which the UAV delivered "Wolfpack" battlefield sensors and other payloads. The Airwolf prototype performed its initial flights in the spring of 2005. The DARPA program ended without a follow-on, but it seems the AirWolf design remains in the BAE Systems portfolio for possible future exploitation.
* There seems to be quite a bit of interest in using small UAVs to deliver cargoes to front-line troops these days. In 2003, SOCOM obtained five "Snow Goose" cargo-delivery UAVs from a Canadian firm named "Mist Mobility Integrated Systems Technology (MMIST)" for evaluation. The Snow Goose, which was given the designation "CQ-10A", consists of a cargo / propulsion / control module with a pusher piston engine, with the module flying under a parafoil and landing on skids. It can carry a payload of up 270 kilograms (600 pounds), including fuel, and can fly autonomously using a GPS-based navigation system.
The Snow Goose can be launched from an aircraft or from a Hummer truck; it can drop its payload without landing and then return to its base. In 2009, MMIST introduced a new version of the Snow Goose with a three-bladed autogyro rotor to permit it to self-launch. The pusher engine drives the rotor up to speed, allowing a vertical takeoff, and then switches back to the pusher engine. The autogyro variant also has higher speed and potentially can be operated off naval vessels, though that will require improvements in its flight control system.
The Army is also investigating use of unmanned helicopters for resupply operations under a program designated "Broad-area Unmanned Responsive Resupply Operations (BURRO)" -- the people in the acronym department were clearly getting cocky again. Tests have involved a Kaman K-MAX eggbeater "flying crane" helicopter modified as a UAV and fitted with a long-range conformal belly fuel tank that was originally designed for carrying retardant. Goals of the program are to develop a robot delivery vehicle that can carry up to 2,729 kilograms (6,000 pounds) to four field locations and then come back to base, all under autonomous operation. Trials seem to be going very well, the K-MAX being a well-proven machine, but it is unclear if there is any commitment to production of the system yet.
* In 2005, Northrop Grumman worked with Swift Engineering of California to develop a light tactical UAV, originally known as the "Killer Bee" and flown as series of demonstrators. The initial demonstrator was a smoothly-curved flying wing with twin rudderons on each wing and a span of 2 meters (6 feet 6 inches), powered by a small two-stroke piston engine driving a pusher propeller. The demonstrator could carry a payload of 3.2 kilograms (7 pounds) for 30 hours, or a 9 kilogram (20 pound) payload for 8 hours. Cruise speed was about 110 KPH (60 KT) at an altitude of 4,575 meters (15,000 feet).
The flying wing design provided high aerodynamic efficiency and plenty of storage volume. For simplicity, the Killer Bee didn't fold up, with its flat profile allowing them to be stacked neatly in a dispenser module. The idea was that the module could be carried on an aircraft, with the UAVs automatically dispensed in "swarms" of three, five, or ten at a time. The UAVs could be dispensed at a speed of hundreds of knots at high altitude, to then fall down to operating altitude. The design was very stable and the UAV would orient itself automatically after dispensing. Its stability made it suitable for launch in high crosswinds, allowing it in principle to be deployed from a naval vessel in poor weather.
A ground-launch system was also designed for carriage of a single Killer Bee on top of a Hummer truck. The launch system deployed two telescoping poles to act as the frame for a bungee launcher, and also held up a net for recovery. The two-meter Killer Bee demonstrator was sized specifically for the Hummer. Smaller demonstrators with spans of 46 centimeters (18 inches) and 1.5 meters (5 feet) were flown, with concepts for machines with a span of up to 9.15 meters (30 feet).
* The program took a confusing turn in late 2006, when Northrop Grumman and Swift parted company, with the "Bat" system, as the Killer Bee was renamed, being taken along with Swift, which then partnered with Raytheon to offer the UAV for a Navy-Marines program. However, in 2009 Northrop Grumman came back and bought up the Bat product line for further development. Northrop Grumman is now flying and promoting two Bat variants, the "Bat-10" and Bat-12", with a wingspan of 3 meters (10 feet) and 3.65 meters (12 feet) respectively.
No service has bought the Bat yet. The baseline Bat based on the two-meter demonstrator is expected to have a diesel engine, and will be constructed of three main composite assemblies. It will have a semi-autonomous flight control system to ease operation. The initial payload will be a small EO/IR turret, but over the long run Northrop Grumman would like to have dual EO/IR turrets that can operate simultaneously and in different directions. The sensor system will include an on-board mass memory so data can be stored and requested by users as needed.
A laser target designator is another possibly payload element, and of course communications relay, jamming, ELINT, and decoy payloads are being considered. The smaller versions would have different powerplant options, including electric motors, hybrid piston-electric engines, and even tiny turbojets like those used in Northrop Grumman's cancelled MALD effort.
* There have been a considerable numbers of other US UAV designs that have been sold in modest numbers, went into limbo, or were complete dead ends. It can be a little difficult to figure out the precise status of some of these machines but clearly most of them have not caught on.
* The "SkyEye" series of UAVs was developed by Developmental Sciences Corporation, which was originally apparently part of Lear Astronautics but which is now a component of BAE Systems. In any case, Developmental Sciences was one of the first US companies to investigate battlefield UAVs, flying the first prototype of their "SkyEye" series in 1973, leading to the first flight of the improved "R4E" variant in 1978.
The SkyEye had the common pusher-propeller twin-tailboom configuration, but it had distinctive slightly-swept wings and antennas on top of the tailplanes. It was powered by a rotary engine and could carry two underwing stores, along with its primary payload. It landed on a retractable centerline skid or can be recovered by parachute. The SkyEye was sold to a number of countries for battlefield surveillance, and has also been used commercially for pesticide spraying. Apparently a few stock R4Es were also purchased by the US Army's Central Command in Latin America and used for border patrols. It is no longer in production.
* DRS Technologies builds a battlefield mini-UAV named the "Sentry" in roughly the same class as the BAI Dragon drone. In fact, the Sentry looks something like a Dragon with a twin-boom raised tail. It is built of carbon composites and Kevlar, and powered by a 19.5 kW (26 HP) piston engine in a tractor configuration.
The Sentry was introduced in 1986, and has been sold in moderate quantities. DRST followed it up with the more capable "Sentry HP", with a broad wing and a vee tail. DRST built another follow-on to the Sentry, a mini-UAV named the "Neptune", which has the interesting feature, as its name implies, that it could be operated off water -- think of it as a "flying boat" UAV. The 11.2 kW (15 HP) pusher engine is mounted high to keep it dry during takeoffs and landings. A number were purchased by the US Navy, either for evaluation special operations.
* In the late 1980s, Sikorsky Aircraft flew a small UAV named "Cypher", with coaxial rotors inside a doughnut-shaped airframe. The doughnut-shaped shroud not only improved safety in handling the machine, it also helped increase lift. The initial Cypher was strictly a demonstrator that lacked full flight capability, with work leading to a true flight demonstrator and then a "Cypher II" , which was evaluated by the US Marines as the "Dragon Warrior". The service did not adopt it.
* An interesting tactical UAV was developed by a company associated with the University of Maryland, Freewing Aerial Robotics Corporation. Working with well-known small-aircraft designer Burt Rutan, Freewing designed a series of piston-powered short-takeoff-and-landing UAVs, based on a design where the fuselage pivoted relative to the wing surfaces. There was considerable buzz over the design for a time, with a production arrangement set up with Matra of France, but apparently no one bought the Freewing and the effort has all but disappeared.
* Bell developed a turboshaft-powered tiltrotor UAV named the "Eagle Eye", which performed its first flight in 1993. Bell pushed the machine for a decade without finding a buyer, but finally obtained a contract in 2002 to produce Eagle Eyes for the US Coast Guard's "Deepwater" modernization program. The program's name turned out to be only too appropriate, however, since it proved more than the service could smoothly manage, and the result was cutbacks and schedule slipouts.
The Eagle Eye was one of the casualties, with the USCG regrouping to consider a cheaper UAV. It appears the Eagle Eye was an impressive machine, but it suffered from a problem that has long plagued VTOL technology development: potential customers just couldn't see that the machine offered enough advantages over a helicopter to justify the higher price tag.
* DARPA conducted a program with the Army on development of prototypes for an "Uninhabited Combat Armed Rotorcraft (UCAR)", originally given the snappy name of "Robotic Rotary Wingman". A requirement was issued in the spring of 2002, specifying a robot rotorcraft to be armed with missiles, unguided rockets, guns, and nonlethal directed energy weapons.
Northrop Grumman and Lockheed Martin were selected in the summer of 2003 to come up with a detailed design. Ironically, neither company had ever built a full-production rotorcraft. The Northrop Grumman design used the twin-two-blade-rotor "eggbeater" scheme usually associated with Kaman helicopters while the Lockheed Martin design used a four-blade rotor with a "no-tail-rotor (NOTAR)" jet exhaust in the tail to cancel torque. Both were "stealthy" designs with weapon stores in internal bays; both eliminated the tail rotor, which is the noisiest element on a conventional helicopter.
The Army seemed very enthusiastic about the program, but then pulled out abruptly late in 2004, to eventually adopt -- and later discard -- the Fire Scout. The UCAR designs were simply too whizzy and futuristic, overkill for actual needs. It's hard to say the UCAR effort was a failure, however, since DARPA's mission is to evaluate next-generation technologies. Sometimes they lead to operational systems, sometimes they don't, but even when they don't the technologies developed can prove useful down the road.
* Along such lines, DARPA has been working with a company named NextGen Aeronautics of Torrance, California, to develop a "morphing-wing" UAV. An initial demonstrator, the 45 kilogram (100 pound), piston-powered "MFX-1", was flown in the summer of 2006. The morphing wing could not only change its sweep -- nothing new there -- but could shift fore and aft along the wingroot, and adjust its chord. At the moment, it appears to be a pure technology-development exercise, with no particular operational use in mind.
DARPA is also working on a particularly interesting program codenamed "RapidEye", which is to be a small UAV to be launched as a payload on a solid-fuel rocket booster that would deliver it quickly to anywhere in the world. The RapidEye UAV would have a folding configuration, along the lines of those of Mars UAVs, discussed in a later chapter. It is unclear if RapidEye will carry a warhead -- though it would be very useful if it did.
The delivery system would not only provide rapid response, it would also permit overflights of any territory on Earth without violations of airspace: by international agreement, space is open territory where rights of navigation cannot be enforced. However, there have been loud concerns over the idea of using a long-range missile for carrying a conventional warload, since the Russians would have difficulty telling it from a missile carrying a nuclear warhead. Whether there is a variation on the concept that would get around this difficulty remains to be seen.
