AN/ALQ-172 is an integrated airborne defensiveelectronic countermeasure system for theB-52 Stratofortress,MC-130E Combat Talon,MC-130H Combat Talon II,AC-130H Spectre andAC-130U Spooky.[1][2] Originally produced byITT Defense & Electronics Corp (now part ofL3Harris Technologies) in the early 1980s, it was designed to improvelow-level penetration survivability of the B-52.[1]
A study in 1996 by analysts of theBattelle Memorial Institute determined problems with repair of the ALQ-172 resulted in the highest cost per flying hour (CPFH) of any system on the B-52.[2][3] TheUnited States Air Force institutedEngineering Change Proposal (ECP) 93 modifying the system'smemory andprocessing capability. Byfiscal year 1997 (FY97), it also reported a second system was needed on the aircraft for fullthreat protection.[2]
Also in FY96,Air Staff directed the ALQ-172 be installed on AC-130H gunships replacing the non-supportableAN/ALQ-131 jamming pods.[2] Also installed on special operations forces (SOF) AC-130U, MC-130H and MC-130E aircraft, two subsystems were installed; one forward and one aft, with a single commondisplay and control unit. Other engineering differences on these aircraft involved adding low-band transmitters, antennae and antenna control units.[2]
Upgrades have incorporatedgeolocation capabilities, advanced countermeasures and new technologies.[4][5] NineLine-replaceable units (LRUs) have been upgraded, with five of those tested as of mid-2024.[5] The upgrades are part of the maintainability and reliability system (MARS) upgrade; a 10-year, $947 million project enhancing the performance of the B-52's electronic countermeasures systems.[5][3] With continuing support and upgrades, the ALQ-172 is expected to be in service well into the 2040s.[4]
Integrated withaircraft controls and displays, the system provides countermeasures capabilities for multiple sophisticated pulse,continuous wave,doppler andmonopulse threats simultaneously.[1][4] Using digital frequency discrimination (DFD) technology, the system is capable of determiningpulse width,angle of arrival (AOA), andpulse-repetition frequency (PRF) of threat signals, deinterleaving and processing them.[2]
In accordance with theJoint Electronics Type Designation System (JETDS), theAN/ALQ-172 designation represents the 172nd design of an Army-Navy electronic device for an electronic countermeasures system. The JETDS system also now is used to name Air Force systems.
| ActiveCountermeasures (Jamming) | |
|---|---|
| PassiveRadar Warning Receivers | |
| Missile Warning Systems | |
| Flare andChaff Systems | |
| Directional IRCM | |
| Dedicated ECM /ESM aircraft | |
