v1.4.1 / chapter 6 of 19 / 01 mar 08 / greg goebel / public domain
* While drones were evolving from simple targets to long-range reconnaissance platforms, they were also being developed as decoys, a logical extension of their role as targets. This chapter describes the evolution of decoy drones.
* The use of drones as decoys goes back at least to the 1950s, with the Northrop Crossbow tested in such a role. The first operational decoy drone was the McDonnell-Douglas "ADM-20 Quail", which was carried by Boeing B-52 bombers to help them penetrate defended airspace.
The Quail was a small aircraft, and its wings and tail folded neatly to make
it even more compact for storage. Four Quails were generally carried in the
extreme rear of a B-52's bomb bay. The bombbay was fitted with a mechanical
system to lower the decoys into the airstream, where they spread their wings
and tail and were launched. The Quail was powered by a General Electric
J85-GE-7 turbojet engine providing 10.9 kN (1,110 kgp / 2,450 lbf) thrust.
MCDONNELL-DOUGLAS ADM-20 QUAIL:
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spec metric english
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wingspan 1.64 meters 5 feet 4 inches
length 3.9 meters 12 feet 10 inches
height 1 meters 3 feet 4 inches
max loaded weight 545 kilograms 1,200 pounds
maximum speed 1,045 KPH 650 MPH / 565 KT
service ceiling > 15,250 meters > 50,000 feet
range 740 kilometers 460 MI / 400 NMI
_____________________ _________________ _______________________
The Quail was designed to be boxy in order to give it a radar cross section
much like that of its B-52 mother ship, and was also fitted with active radar
reflection enhancement devices, as well as chaff and flare dispensers to
further confuse enemy defenses. Its autopilot system could be programmed to
provide one change of speed and two turns.
The Quail evolved from studies initiated by the USAF in 1952. In 1956, the Air Force awarded a development contract to McDonnell as prime contractor, leading to flight tests and a production contract in 1958. The first model of the Quail was originally designated "GAM-72" (later "ADM-20A"), with 24 built for flight tests in 1961. This was followed by the full production "GAM-72A (ADM-20B)", with a total of 500 built to final production in 1962. Most of the ADM-20Bs were modified for low-level operations by the addition of a barometric altimeter, and redesignated "GAM-72B (ADM-20C)", with the first ADM-20C appearing in 1963.
The Quail remained in firstline service through the 1960s, but during a test exercise in 1972, radar operators were able to recognize the decoy 21 times out of 23. The USAF began to phase out the Quail, and all were out of service by 1978. Quail was to have been replaced by the "Supersonic Cruise Armed Decoy (SCAD)". This project was cancelled in 1973, but eventually gave rise to the AGM-86 Air Launched Cruise Missile (ALCM), which became a significant weapon in the USAF inventory.
* By the early 1970s, Brunswick Defense Corporation of Costa Mesa, California, was well into development of a series of less sophisticated decoys that would see much more operational use. Brunswick had worked on decoy concepts through the 1960s, leading to a USAF contract in 1968 for a technology demonstration. The result was the "Maxi-Decoy" series, which were also intended to support radar jamming, chaff-flare dispensing, and ELINT missions.
The first of the series was the "Model 150", first flown in 1973, which was an unpowered glide decoy with pop-out "switchblade" wings. It weighed only 59 kilograms (130 pounds), and two could be carried on an underwing stores pylon. The Model 150 led to the scaled-up "Model 300", which was similar but weighed 180 kilograms (400 pounds), giving it much greater payload capacity. Speed and range of these gliders was of course dependent on the speed, altitude, and launch angle of the launch aircraft, but was nominally up to about 750 KPH (460 MPH) and 140 kilometers (87 miles).
The third in the Maxi-Decoy series was the "Model 290P". The "P" apparently stood for "powered", since the Model 290P had a solid rocket motor that could burn for up to 300 seconds. It was otherwise similar in configuration to its predecessors, and weighed 136 kilograms (300 pounds). The USAF did not order production of the Maxi-Decoys, but Brunswick sold an unpowered decoy named "Samson" to the Israelis. It seems the Samson was a variant of the Model 300 Maxi-Decoy.
The Israelis had lost far too many aircraft to Arab air defenses during the Yom Kippur War in 1973, and decided to invest in decoys as a countermeasure in future conflicts. The Samson decoys were part of the suite of countermeasures the Israelis used over the Bekaa Valley in Lebanon in 1982 against Syrian air defenses with dramatic effect.
The US Navy suffered at the hands of Syrian air defenses during America's intervention in Lebanon in 1983, and so Navy officials decided to follow the Israelis' example. In 1985, the Navy awarded Brunswick a contract to provide 1,000 "ADM-141A Tactical Air Launched Decoys (TALD)".
TALD is an improved version of the Samson. TALD weighs from 180 to 204 kilograms (400 to 450 pounds), depending on payload, and up to six can be carried on a single stores pylon, using a pair of triple ejector racks. It has a glide ratio of better than 10:1, and can achieve ranges of over 100 kilometers (60 miles) when released at altitude. The Navy bought two versions of TALD: the "RF-TALD", which uses radar enhancement devices to provide radar signatures of different types of attack aircraft or a Tomahawk cruise missile, and the "Chaff-TALD", which carries 36 kilograms (80 pounds) of chaff.
Brunswick supplied the original batch of 1,000 TALDs, but later batches were built by an arrangement between Brunswick and Israeli Military Industries (IMI), and in 1987 McDonnell-Douglas became a second-source manufacturer. A total of about 4,000 TALDs were produced into the early 1990s.
* The US Navy's TALDs proved successful in baffling Iraqi air defenses in the Gulf War, but as discussed later in this chapter, the Air Force used powered drones as decoys with such good effect that the Navy decided to obtain an "Improved TALD (ITALD)" with a turbojet engine.
The "ADM-141C ITALD" is similar to TALD, but is fitted with a Teledyne CAE-312 turbofan engine, which provides 0.78 kN (80 kgp / 177 lbf) thrust and was developed for a cancelled anti-radar cruise missile named "Tacit Rainbow". ITALD has a ventral intake for the turbofan, and a radar altimeter so it can maintain low-level flight at a specified altitude over the ground.
ITALD has a speed of Mach 0.8 and range of 280 kilometers (175 miles) at altitude. It can be launched from the ground using a RATO booster, as well as air launched. First flights were in 1995, with trials completed in 1996. At that time, Brunswick got out of the defense business, but the project was picked up by IMI. The US Navy is now asking IMI to add a Global Positioning System / Inertial Navigation System (GPS-INS) autopilot to ITALD.
* The Israelis were users of Northrop Chukar drones as targets and expendable reconnaissance platforms, and also used them as decoys during the 1973 Yom Kippur war, but to no great effect. The Chukars were available to the US Navy for use as decoys during the American intervention in Lebanon in 1982 but weren't employed, much to the Navy's regret.
Just before Iraq invaded Kuwait in 1990, Northrop briefed US Air Force officials on how decoys could be used for military operations in the Middle East. After the invasion, a USAF officer named Colonel John Warden, who was attached to the planning staff for the air war, remembered the briefing and suggested the use of decoys. The USAF Big Safari group was put in charge of the decoy effort, which was codenamed Project SCATHE MEAN.
The BQM-74C Chukar drones that were available were usually launched from DC-130 director aircraft, and could also be launched from strike aircraft such as F-15s or F-16s. These resources were not available, so the Navy found twelve ground launchers in their inventory that could be made serviceable, while RATO booster units were found stockpiled in Belgium. Each BQM-74C was fitted with a pair of passive radar enhancement devices to give it a signature similar to that of a strike fighter.
A 40-person team of specialists, obtained from disbanded ground-launched cruise missile units, was assembled in a few days and designated the "4468th Tactical Reconnaissance Group". The 4468th moved on a fast track, with trucks modified and obtained from a California commercial trucking firm, tool kits purchased from Sears, and field gear bought from war surplus stores. The teams were given quick training, equipped with 44 Navy BQM-174Cs, and sent to Saudi Arabia in two six-launcher teams in about two weeks, arriving near the Iraqi border on 15 October 1990. The northern team was sited to cover Baghdad and large military bases in that area, while the southern team was sited to cover Basra and Kuwait City. The two teams practiced launches while wearing chemical-protection suits and night-vision goggles.
When the air war began on the night of 17 January 1991, Iraq was hit by waves of Lockheed F-117 stealth fighters and Tomahawk cruise missiles. 38 BQM-74Cs were assigned to be launched as a diversion for the second wave of attacks, with the launches generally in groups of three, and 37 were launched successfully in precisely timed waves. One group of three was intercepted by Iraqi aircraft, while all the others made it to target.
The drones flew over 500 kilometers (310 miles) at 630 KPH (390 MPH), then began to orbit Baghdad for up to 20 minutes. Iraqi air defense radars probed for the drones and were immediately destroyed by Allied strike aircraft firing high-speed antiradiation missiles (HARMs). The Navy also launched TALDs to contribute to the countermeasures blitz. Iraqi air defenses never recovered from the blow, and though heavy Allied aircraft losses had been predicted, the Iraqis only succeeded in shooting down a handful. After the war, the 4468th was disbanded, and one of the remaining BQM-74Cs was donated to the US Air Force Museum at Wright-Patterson AFB in Ohio, where it is now on display.
* The resounding success of decoys in the Gulf War led to heightened interest by the US armed services in the concept, and in 1996 the US Defense Advanced Research Projects Agency (DARPA), with USAF encouragement and cooperation, initiated a competition for a "Miniature Air-Launched Decoy (MALD)" demonstrator.
A number of aerospace firms responded. One strong contender for the award was a decoy version the Lockheed Martin Vought "Low-Cost Autonomous Attack System (LOCAAS)", a small anti-armor cruise missile with search-and-destroy capabilities then in development. However, Ryan, which had been bought out by Northrop Grumman in 1999, won the DARPA MALD award with an entirely new design.
The Northrop Grumman "ADM-160A", as its MALD demonstrator was eventually designated, was a slender UAV powered by a tiny Hamilton Sundstrand TJ-50 turbojet. The demonstrator was 2.3 meters (7 feet 7 inches) long, had pop-out wings with a span of 65 centimeters (25 inches), and a launch weight of 40 kilograms (88 pounds). Three of them could be carried on a single stores pylon using a triple ejector rack. The MALD demonstrator was designed to fly at high subsonic speed for about 20 minutes. It used a programmable waypoint guidance system with GPS navigation, and had a programmable active radar enhancement payload that in principle could allow it to impersonate almost any combat aircraft. Cost estimates for a production version were about $30,000 USD each. The USAF planned to buy about 1,500 MALDs, and the US Army and the British also expressed interest in the weapon.
* The MALD program seemed to be going well, with initial test flights in 1999, and received very good press. Another demonstrator program was spun off the MALD effort, in the form of the "Miniature Air Launched Interceptor (MALI)", a supersonic version of the AGM-160 intended to shoot down cruise missiles. It featured a new, uprated Hamilton Sundstrand TJ-120 engine, streamlined nose, and wings with greater sweep. An initial MALI test flight took place in late 2001.
There was also interest in a ground-launched version of MALI with a solid-rocket booster; an expendable jammer variant of the MALD, known as "MALD-J"; and a light cruise missile derivative of the MALD. However, much to almost everyone's surprise, the MALD demonstrator program was cancelled in January 2002 before it had run its course.
DARPA, which only runs three-year investigation programs, had turned over the effort to the Air Force, and then the program ran into what appears to have been dissatisfactions and second thoughts. The Air Force decided that the MALD demonstrator didn't have the range or endurance to be the decoy the service wanted, and would not have been a good platform for other roles. That meant committing to a more sophisticated and expensive decoy. However, the MALI demonstration program was completed, with a MALI demonstrator achieving Mach 1.1 during test flights in late 2002.
* The USAF restarted the competition, specifying a new small decoy with an endurance of 45 minutes or more at 10,670 meters (35,000 feet) and 20 minutes or more at 915 meters (3,000 feet). Of course the service realized that a more capable decoy was going to be more expensive, and so the service dictated an absolute cost ceiling of $125,000 USD per item, along with a cost target of $75,000 USD per unit for a buy of 1,500 MALDs.
Raytheon won the award in the spring of 2003. The configuration of the Raytheon design was originally very similar to that of the original demonstrator, to the extent that they could be confused if not seen side-by-side, but after the award of the contract the design evolved to a new configuration that featured a fuselage with a trapezoidal cross section to make carriage easier. The Raytheon "ADM-160B MALD" is much heavier, with a weight of 113 kilograms (250 pounds), a length of 2.84 meters (9 feet 7 inches), and a wingspan of 1.71 meters (5 feet 7 inches) -- with the wings extended to a straight position for range and endurance, instead of swept for speed.
The ADM-160B is powered by a Hamilton Sundstrand TJ-150 engine, an uprated derivative of the TJ-50 of the original demonstrator, and gives the decoy a top speed of Mach 0.91 at 12,200 meters (40,000 feet). Hamilton Sundstrand also provides an alternator and power control system to run the drone's avionics, which includes a GPS-based navigation system and a Raytheon-developed active radar signature enhancement payload that can be programmed to mimic different classes of aircraft.
Initial powered flight of an ADM-160B was in June 2007, with initial production planned for 2008. MALD will initially be qualified on the B-52H and F-16, but will eventually be carried by all USAF strike-capable aircraft. The Air Force remained ambivalent about the MALD-J jammer variant for a time, but its priority has risen. The USAF would like to make sure at the very least that the same MALD airframe can accommodate either decoy or jammer gear.
Raytheon has every good reason to design MALD to be as flexible as possible, since if the MALD decoy version is validated in test and service and proves satisfactory, the airframe is likely to be the basis not merely for MALD-J, but also for an operational MALI, a light precision-strike cruise missile, or a loitering antiradar attack drone. Ground, ship, or even submarine-launched versions could follow, and the production quantities would be a real prize. However, it appears that, since the ill-fated demonstrator effort was promoted along such lines, the Air Force is sensibly very cautious about overselling MALD and wants to validate the decoy variant before pushing on.
