Military Wiki
AN APQ-120 fire control radar in the nose of F-4E Phantom II.jpg
Country of origin United States
Type Fire control

The AN/APQ-120 was an aircraft fire control radar (FCR) manufactured for the McDonnell Douglas F-4E Phantom II and it was manufactured by Westinghouse. AN/APQ-120 has a long line of lineage, with its origin traces all the way back to Aero-13 FCR developed by the same company in the early 1950s. A total of half a dozen FCRs were tested and evaluated on the first 18 F-4s built,[1] but they were soon replaced by later radars produced in great numbers, including AN/APQ-120.

Aero 13[]

Aero 13 FCR designed for Douglas F4D Skyray is origin of AN/APQ-120, and it established the configuration of the airborne FCR not only for the radar families of AN/APQ-120, but also a standard for all other airborne radars to follow: Aero 13 FCR was designed as an integrated cylindrical module that could be plugged into the nose of an aircraft, instead of a set of semi-independent black boxes.[1]

Aero 1A[]

Aero 13 did not have any capability for semi-active radar homing (SARH) air-to-air missile (AAM)s. 1A FCR was developed to add this capability by incorporating a continuous wave illuminator for SARH AAMs. This configuration of Aero 1A remained unchanged for later radars for F-4s all the way until AN/APQ-50.[1]


The next radar to be installed on F-4 prototypes and pre-production series was AN/APQ-35, which was actually consisted of two radars: the AN/APS-21 search radar that could locate fighter-size targets at a range of 32 kilometers (20 miles), and the AN/APS-26 targeting radar, with a range of 3.2 kilometers (2 miles).[2]

Maintenance on an APQ-35 radar of a F3D-2 in Korea, 1953


AN/APQ-36 is the improvement over earlier AN/APQ-35, and when AN/APQ-36 entered service on Douglas F3D Skyknight and Vought F7U Cutlass, it was the largest airborne FCR of its time. The more powerful AN/APQ-36 with large size did not have any problem being installed on F-4 prototypes, so that more powerful FCR of larger size would be developed.[3]


The AN/APQ-41 is the improvement over AN/APQ-36, and it is designed to provide air intercept, search, to automatically track a selected target, and to supply lead angle and range information. Facilities are also provided for air-to-surface search, for beacon interrogation and response display, and for response display when used in connection with identification friend or foe (IFF). Specifications:[4]

  • Search or Gun-Aim Range: 24 naut mi max, 200 yd min
  • Ground Mapping Range: 100 naut mi
  • Beacon Range: 200 naut mi
  • Reliable Gun-Aim Prediction: 2,000 yd max
  • Tracking Accuracy: 25 yd within the ranges of 200 and 2,000 yd
  • Future Range Accuracy: 25 yd
  • Azimuth (Search): 106.5 deg
  • Elevation (Search): 13 deg (within 30 deg of aircraft center line)
  • Azimuth (Track): 116.5 deg
  • Elevation (Track): 116.5 deg
  • Accuracy (Search and Track): 4% all indications
  • Type of Presentation:
    • B-scope (Search)-Target azimuth and range, range strobe, range markers, beacon and IFF responses
    • C-scope (Search)-Target strobe, targets, straddled by range strobe, artificial horizon line, scan pattern
    • C-scope (Track)-Target dot, range rate circle and dot, artificial horizon line
  • Fixed Range Marker: 25-mi markers on 100 and 200-mi scales
  • Radar Frequency (Search and Track): 9375 30 mc
  • Beacon Frequency: Transmitting, 9375 30 mc; receiving, 9310 1 mc
  • Operating Temperature:-55 to +55 deg C
  • Altitude Limit: 52,000 ft


AN/APQ-46 is the last radar tested and evaluated on F-4 prototypes and pre-production series. F-4 equipped with this radar was specifically modified to meet US Navy Ferret electronic countermeasure aircraft requirement, which eventually did not materialize.[1]


AN/APQ-50 is the radar installed on low-rate initial production batch of F-4s, but as with earlier radars, it was not used in great numbers in comparison to later radars of the same family. The parabolic antenna is 24 inches in diameter, and in addition to providing all weather capability, AN/APQ-50 FCR also provides information on automatic firing of rockets.[5]


AN/APQ-72 FCR is a development of AN/APQ-50, with diameter of the antenna increased by a third to 32 inches from the original 24 inches of AN/APQ-50. AN/APA-128 CW illuminator is integrated with the radar to give it a capability for radar guided AAMs. AN/APQ-72 is the first radar installed on F-4s to be build in great numbers, starting with the 19th F-4 produced.[5]


AN/APG-59 FCR is a modified AN/APQ-72 designed for British. The main difference between AN/APG-59 and its predecessor AN/APG-72 is that AN/APG-59 had a radar dish which could be swung sideways in order to reduce the length of the aircraft to 54 feet so that it could fit on the small deck lifts of British carriers. Used in the AN/AWG-10.[6]


AN/APQ-100 is the replacement of AN/APQ-72, and it featured a redesigned radar scope in the rear cockpit that offered a planar position indicator (PPI) mapping display option, and adjustable range strobe for bombing. For air-to-ground missions, the radar interfaced with the inertial platform on F-4.[7]


Modified AN/APQ-100 for British to replace AN/APG-59. As with AN/APG-59, AN/APG-60 also had a radar dish which could be swung sideways in order to reduce the length of the aircraft to 54 feet so that it could fit on the small deck lifts of British carriers. AN/APG-60 was later upgraded with Doppler capability during its upgrades, and integrated in the AN/AWG-11.[1]


AN/APQ-109 is an improvement of earlier AN/APQ-100 with an improved cockpit display able to handle TV imagery from weapons such as AGM-62 Walleye. Other significant addition included air-to-ground ranging, ground beacon identification and display capabilities. AN/APQ-109 was an improved, more reliable "hybrid" version of the AN/APQ-100 with solid-state components in the low-voltage sections.[7]


Modified AN/APQ-109 for British to replace AN/APG-60. As with AN/APG-59/60, AN/APG-61 also had a radar dish which could be swung sideways in order to reduce the length of the aircraft to 54 feet so that it could fit on the small deck lifts of British carriers. Used in the AN/AWG-12.[1]


AN/APQ-117 terrain following and attack radar is developed from earlier AN/APQ-109, with terrain following capability added.[8]

A fully solid-state radar developed from AN/APQ-117. AN/APQ-120 radar was much more compact than its predecessors, allowing it to fit into the nose along with the cannon, and the radar was later integrated into AN/AWG-14.[7]


AN/AWG stands for Army/Navy Airborne Weapons Group, meaning that all avionics on board the aircraft are integrated together as a single coherent unit, thus greatly improved combat efficiency and effectiveness, because pilots no longer needed to manually feed information from one system to another like they used to. AN/APG-59 was the first FCR integrated into AN/AWG-10, which developed into two more versions, A and B. Original AN/AWG-10 can detect an aerial target with 5 square meters radar cross section more than 100 kilometers away.

AN/AWG-10A is a development of the original AN/AWG-10, with great improvement in reliability and maintainability by replacing the original transmitter in AN/AWG-10 by a solid state unit whose only tube was a klystron power amplifier. An addition of digital computer allowed much more effective missile launch equations. AN/AWG-10A also incorporated a new servoed optical sight. There are also additions of new modes such as continuously displayed impact point mode, freeze displayed impact mode, and computer released visual mode. AN/AWG-10B is a fully digitized version of AN/AWG-10/10A,[9] with traveling wave tubes replaced the klyston.


AN/AWG-11 is a British license-built AN/AWG-10 by Ferranti. The radar used was AN/APG-60, and AN/AWG-11 is slightly modified AN/AWG-10 in that it's compatible with AGM-12 Bullpup and WE.177, so that British F-4s can perform nuclear strike missions if needed to.[10]


AN/AWG-12 is an improved AN/AWG-11 built by Ferranti with AN/APG-61 FCR. The main difference between AN/AWG-11 and AN/AWG-12 is that the latter has better ground mapping mode, and it also can control belly mounted SUU-23/A Vulcan. AN/AWG-12 finally retired in 1992 when the last F-4s in British service retired, and during its service life, it was upgraded with improvements of AN/AWG-10A/B.[10]


AN/AWG-14 is the final member of the lineage of radar family, and it is a fully digitized upgade of AWG series[11] incorporating AN/APQ-120. The open architecture and modular design enable AWG-14 to accommodate different radars, such as AN/APG-65, AN/APG-66, AN/APG-76, Elta EL/M-2011/2021 and EL/M-2032.

See also[]