ALQ-144
Encyclopedia
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
infra-red guided missile countermeasure devices (IRCM
IRCM
An infrared countermeasure is a device designed to protect aircraft from infrared homing missiles by confusing the missiles' infrared guidance system so that they will miss their target.- History :...
). They were developed by Sanders Associates in the 1970s to counter the threat of infra-red guided surface to air missiles like the SA-7 Grail. While decoy flares were effective at jamming first generation infra-red guided missiles, each flare was only effective for a short period of time, if an aircraft needed to loiter over a high risk area, or was flying slowly (as helicopters do) it would require a large number of flares to decoy any missile fired at it. The IRCM provided constant protection against infra-red guided missiles.
The ALQ-144 and ALQ-147 were first delivered to the US military in 1981. Currently there are over 3,500 in use with the US military, and a total of 6,000 in use by 19 countries globally. 700 ALQ-157 systems are currently in service.
ALQ-144/ALQ-147
Both systems consist of a heated Silicon Carbide block that radiates a large amount of infra-red energy, it is surrounded by a large cylindrical mechanical shutter, that modulates the infra-red output, producing a pulsing pattern. Early infrared guided missiles used a rotating reticle, when a target was not on the sensor's centerline, it would produce a pulse as the reticle swept over the target. When the target was on the sensor's centerline, the sensor would produce a constant signal. This constant signal was required by the early missiles to produce a "lock on" that would allow a launch.The ALQ-144 and 147 IRCM produced a pattern of pulses that was approximately synchronized with the rotation rate of these reticles. Before launch this would prevent the missile actually locking onto the target, preventing the operator from firing the missile. After launch this would cause the missile to think that the target was off to one side, and cause the missile to steer away from the aircraft carrying the IRCM.
The introduction of rosette and "staring" scanning techniques in second generation missiles reduced the effectiveness of the ALQ-144 and 147, later upgrades restored the effectiveness of the jammers.
The ALQ-144A was rushed into US service in time for the 1991 Gulf War
Gulf War
The Persian Gulf War , commonly referred to as simply the Gulf War, was a war waged by a U.N.-authorized coalition force from 34 nations led by the United States, against Iraq in response to Iraq's invasion and annexation of Kuwait.The war is also known under other names, such as the First Gulf...
, as Iraq had stocks of SA-14 and SA-16 missiles, against which the ALQ-144 was only partially effective. By the time the war started two-thirds of the AH-64 Apache
AH-64 Apache
The Boeing AH-64 Apache is a four-blade, twin-engine attack helicopter with a tailwheel-type landing gear arrangement, and a tandem cockpit for a two-man crew. The Apache was developed as Model 77 by Hughes Helicopters for the United States Army's Advanced Attack Helicopter program to replace the...
s in the Gulf had been upgraded to ALQ-144A standard. The only AH-64 Apache lost to an infra-red guided missile was hit by a SA-14 missile, the helicopter in question was one of the few that hadn't been upgraded.
The ALQ-144's distinctive appearance has earned it the nicknames "disco light" or "disco ball".
ALQ-157
Produced by Loral, the system consists of two emitters, each one covering one side of a large aircraft. The system is microprocessor controlled and has five pre-set jamming patterns.Specifications
| Designation | Entered service | Output | Weight | Platforms |
|---|---|---|---|---|
| ALQ-144 | 1980 | 1.7 kW | 12.5 kg | |
| ALQ-147 | 1980 | ? | ? | |
| ALQ-157 | 1984 | 2 kW (later 4 kW) | 99 kg |
Variants
- ALQ-144 electrically powered IRCM
- ALQ-144A upgraded system to deal with more recent generations of IR guided missiles.
- ALQ-144A(V)1 – Standard in helicopter jammer
- ALQ-144A(V)3 – Added RFCM on/off switch
- ALQ-144A(V)5 – Increased protection with a dual phaselocked transmitters and jam code selector switch on the operator
control unit
-
- ALQ-144A+ – Increased protection with the higher power
- ALQ-144A+(5) – Increased protection plus with the dual phaselocked ALQ-144A+ transmitter
- ALQ-147 mounted in a modified 150 US gallon (570 liter) drop tankDrop tankIn aeronautics, a drop tank is used to describe auxiliary fuel tanks externally carried by aircraft. A drop tank is expendable and often jettisonable...
, it is a fuel powered IRCM.- ALQ-147A upgraded system to deal with more recent generations of IR guided missiles.
- ALQ-157 large aircraft version of the system fitted to CH-47 ChinookCH-47 ChinookThe Boeing CH-47 Chinook is an American twin-engine, tandem rotor heavy-lift helicopter. Its top speed of 170 knots is faster than contemporary utility and attack helicopters of the 1960s...
and C-130 HerculesC-130 HerculesThe Lockheed C-130 Hercules is a four-engine turboprop military transport aircraft designed and built originally by Lockheed, now Lockheed Martin. Capable of using unprepared runways for takeoffs and landings, the C-130 was originally designed as a troop, medical evacuation, and cargo transport...
aircraft, consists of two units, each giving semi-circular coverage.- ALQ-157M upgraded system to deal with more recent generations of IR guided missiles.
See also
- CAMPSCAMPSCivil Aircraft Missile Protection System or CAMPS is an infrared countermeasure against infrared-homed anti-aircraft missiles, specifically designed to defend civilian aircraft flying under against MANPADS....
Civil Aircraft Missile Protection System - Electronic warfareElectronic warfareElectronic warfare refers to any action involving the use of the electromagnetic spectrum or directed energy to control the spectrum, attack an enemy, or impede enemy assaults via the spectrum. The purpose of electronic warfare is to deny the opponent the advantage of, and ensure friendly...
- Electronic countermeasuresElectronic countermeasuresAn electronic countermeasure is an electrical or electronic device designed to trick or deceive radar, sonar or other detection systems, like infrared or lasers. It may be used both offensively and defensively to deny targeting information to an enemy...
- EA-6B ProwlerEA-6 ProwlerThe Northrop Grumman EA-6B Prowler is a twin-engine, mid-wing electronic warfare aircraft modified from the basic A-6 Intruder airframe. The EA-6B has been in service with the U.S...
- EA-18G Growler
- СОЭП Липа