AN/APG-78 Longbow

AN/APG-78 Longbow
Hunini · CC BY-SA 3.0 · source
Name	AN/APG-78 Longbow
Origin	United States
Type	Fire-control radar / targeting radar
Used by	United States Army; allied users
Designer	Northrop Grumman (formerly Westinghouse Electronic Systems)
Manufacturer	Northrop Grumman
Production date	1990s–present

AN/APG-78 Longbow is an American millimeter-wave fire-control radar and targeting system developed for rotary-wing attack and fixed-wing strike aircraft to detect, classify, and prioritize targets and to guide radar-homing munitions. It was fielded to improve target acquisition, situational awareness, and weapon effectiveness against armored formations and hardened positions, integrating with avionics suites and weapon systems for networked command and control. The system influenced doctrine, procurement, and tactics across multiple services and allied forces during late 20th and early 21st century conflicts.

Development and Design

The Longbow program traces to Cold War requirements for enhanced anti-armor capability against Warsaw Pact formations, with development involving U.S. Army, Bell Helicopter Textron, Boeing, and defense contractors such as Westinghouse Electric Corporation and later Northrop Grumman. Early concept work intersected with projects overseen by DARPA, requirements shaped by analyses from TRADOC, and funded through procurement decisions made by Congress. The radar employs a millimeter-wave active electronically scanned array (AESA) and doppler processing concepts familiar from contemporaneous programs like AN/APG-63 and influenced by research at MIT Lincoln Laboratory and Georgia Tech Research Institute. Design priorities included all-weather operation, fire-and-forget engagement tactics reminiscent of developments in Raytheon and BAE Systems missile guidance, and integration with targeting systems used on platforms such as the Boeing AH-64 Apache and avionics suites from Honeywell International Inc..

Technical Specifications

The AN/APG-78 Longbow is a millimeter-wave radar operating in the millimeter band using pulse-Doppler and synthetic aperture modes, providing automatic target detection, classification, and ranging. Key subsystems parallel technologies in AESA arrays produced by firms like Raytheon Technologies and signal processors akin to systems from Texas Instruments; components include a rotating mast-mounted radar head, cooling and power electronics, mission computers, and databus interfaces compatible with standards influenced by MIL-STD-1553 and communications suites used by Lockheed Martin. The radar supports target handover to fire-control systems guiding weapons comparable to the AGM-114 Hellfire family and coordinates with navigation sensors such as those made by Northrop Grumman and Garmin. Performance parameters include range categories for detection, classification, and targeting against armored vehicles, and track-while-scan capacities that enable simultaneous engagements and reduce exposure time in contested airspace.

Operational History

Longbow entered service during the post-Cold War era and saw notable employment in regional conflicts, shaping tactics used by units from formations commanded under United States Central Command and operations like Operation Desert Storm post-conflict modernization efforts. Units from 1st Cavalry Division, 101st Airborne Division (Air Assault), and 3rd Infantry Division incorporated platforms equipped with the radar for combined-arms maneuvers and anti-armor missions. Coalition partners from United Kingdom, Israel, and other NATO members evaluated or fielded variants in exercises alongside assets from Royal Air Force squadrons and armored units such as Royal Armoured Corps. The system's ability to operate in degraded visual environments influenced doctrine promulgated by U.S. Army Training and Doctrine Command and was integrated into large-scale exercises like Operation Bright Star and multinational training events hosted by NATO.

Variants and Upgrades

Over time the Longbow family evolved with upgrades paralleling modernization paths followed by systems like the AN/APG-70 and later AESA developments. Enhanced processing, software-defined radar modes, and reliability improvements were implemented in service life enhancement programs managed by U.S. Army Materiel Command and contractors including Northrop Grumman Electronic Systems. Variant adaptations targeted fixed-installation applications, airborne podded versions, and export-improved suites compatible with export controls administered under ITT Export Regulations and policy frameworks such as Arms Export Control Act. Incremental upgrades added features for improved identification friend or foe (IFF) interoperability, datalink enhancements comparable to those used on F-16 Fighting Falcon upgrades, and reduced maintenance footprints using logistics practices from Defense Logistics Agency.

Platform Integration and Deployment

Primary integration was with the Boeing AH-64 Apache rotorcraft through mast-mounted installation, enabling mast-mounted over-the-horizon target detection while the airframe remained masked by terrain. Integration efforts required avionics interfaces with mission computers similar to those on F-35 Lightning II development paths and compatibility with cockpit displays produced by Elbit Systems and Rockwell Collins. The radar has been adapted for use on multiple helicopter platforms, ground-based test rigs, and in some evaluations for use on unmanned platforms developed by companies like General Atomics and Northrop Grumman. Deployments emphasized combined-arms cooperation with units from U.S. Army Aviation Branch, artillery brigades equipped with systems like M142 HIMARS, and reconnaissance elements such as 1st Cavalry Division scouts.

Operators and Export

Operators include the United States Army as the primary user, with foreign military sales to allied nations vetted through Defense Security Cooperation Agency processes. Exported and evaluated users included militaries from United Kingdom, Israel, Egypt, Saudi Arabia, and other U.S. partner states, subject to bilateral agreements negotiated with the Department of State. Procurement decisions often involved offsets and industrial participation agreements with national firms like BAE Systems, Elbit Systems, and local defense industries influenced by foreign military sales cases adjudicated by Congress.

Countermeasures and Survivability

Counter-countermeasure development involved electronic protection features similar to suites fielded on aircraft protected by systems from Northrop Grumman and Raytheon, addressing electronic warfare threats posed by systems developed by suppliers to adversary forces such as those from Russia and networks analyzed by RAND Corporation. Survivability improvements included emissions control tactics taught in curricula by U.S. Army Aviation Center of Excellence, integration with self-protection suites from L3Harris Technologies, and tactics developed during exercises like Red Flag to mitigate radar homing and suppression threats. Adversary developments in radar warning receivers and jamming, studied by analysts at James Martin Center for Nonproliferation Studies and Center for Strategic and International Studies, continue to influence upgrade priorities.

Category:Aircraft radars