AN/APQ-116

This is the first terrain-following radar for use on crewed aircraft, designed by Bert Bechtel, a former Navy engineer, who had designed a radar scan template control technique that permitted safe aircraft descent in adverse weather. The concept was the basis of winning a $750,000 US Army contract to develop a radar system to automatically guide a drone aircraft. The US Army did not pursue the project to production, but the US Air Force became interested and believed that Bechtel's innovation would protect the low-flying planes.[2]

Terrain-following/ground-mapping radar by Texas Instruments for OV-1 Mohawk[1]

TFR tested on T-2 Buckeye for pilots to familiarize TFR operation on other combat aircraft.[1]

Developed by TI as a multi-modes radar,[2] in addition to terrain avoidance and terrain-following modes, and AN/APQ-99 can also be used for ground mapping. Smaller in size then the Westinghouse AN/APQ-72 and fitted in the nose of for A-7A, RF-4B/C. AN/APQ-99 is also supplied to Germany, Iran and Japan.

Terrain-following radar by Texas Instruments.[1]

K_u band terrain-following radar by Texas Instruments for General Dynamics F-111A and RF-4C. It replaced the side-looking mapping radar by Goodyear Tire and Rubber Company on RF-4C.[1]

Improved AN/APQ-110 terrain-following radar by Texas Instruments for the A-7A, General Dynamics F-111, RF-4C, and C-130E. AN/APQ-115 has a single contoured, spoiled parabola antenna, with a search cone of 5 degrees wide, spanning from +7 degrees above to -18 degrees below to the boresight of the aircraft. AN/APQ-115 suffered from inaccurate references (poor stabilization and Doppler inputs), which directly lead to the development of more advanced system such as AN/APQ-122.[3]

The Texas Instruments I-band AN/APQ-116 is a TFR used in A-7 Corsair II[1] and C-130 Hercules aircraft. AN/APQ-116 was basically the integration of previously independent AN/APQ-115 TFR into the ILAAS digital navigation system. The radar also fed a digital weapons computer which made possible accurate delivery of bombs from a greater stand-off distance, greatly improving survivability compared with faster platforms such as the F-4 Phantom II.

X band multi-mode radar by Texas Instruments for C-130 Hercules, Boeing RC-135, Boeing T-43 and Boeing E-4. AN/APQ-122 has a slotted planar array antenna with a separate X-band receiver used to generate MRI video, with a search cone of 7.5 degrees wide, spanning from +8 degrees above to -17 degrees below to the boresight of the aircraft. For AN/APQ-122(V)B, the stabilization reference could either be manually or automatically switched to MD-1 gyro if the LN-15J inertial navigational system become unreliable or inoperable, thus terrain following operation can still continue, where in earlier system such as AN/APQ-115, if the Doppler fails, the terrain following operation would be discontinued.[1]

60 kW improved AN/APQ-116 J band terrain-following radar by Texas Instruments for A-7D/E AC-130 and CH-53 Sea Stallion.[4] This is primarily AN/APQ-116/122 incorporating improved maritime capability. Specifications:[5]

• Maritime surface search: (high altitude): 150NM
• Maritime surface search: (low altitude): 106NM
• Maritime surface search (vs. small contacts): 51NM
• Land surface search (med altitude): 34NM
• Air search: 20NM
• Terrain following: 19NM

K_u band terrain-following radar by Texas Instruments to replace AN/APQ-110 for F-111A/FB-111A.[1]

K_u band multi-mode radar by Texas Instruments for B-57G specially designed for night interdiction missions in Vietnam.[1]

Improved AN/APQ-134 K_u band terrain-following radar by Texas Instruments for F-111C/F.[1]

TFR for initial batch of MH-60K[6]

Improved AN/APQ-141 terrain-following radar by Texas Instruments for HH-53.[1]

Improvement of AN/APQ-126 with 15 line replaceable units for the MH-53 Pave Low helicopter and PAVE LOW III requirement. Designed to perform terrain following mode/function in high clutter area such as in cities.[1]

Development of AN/APQ-99 for RF-4C, incorporating experience gained from AN/APQ-116 and other radars in the family.[1]

multi-mode radar by Texas Instruments for HH-60D & MH-60K. Increased jamming resistance, improved weather penetration, better guidance in turn flight, and better power management function in semi-covert mission. The radar can operate in terrain-clearance, terrain-avoidance, air-to-air ranging and cross-scan modes, the latter combining ground-mapping or terrain-avoidance with terrain-following. A terrain storage facility permits the radar to have a reduced duty cycle, thereby reducing the probability of detection by enemy ESM equipment. There's also the incorporation of built-in test (BITE) provides a high degree of fault isolation and detection.[1]

Improved AN/APG-146 terrain-following radar by Texas Instruments for F-111C/F, developed by Texas Instruments in the mid- eighties with the objective of replacing the four different TFR models used across the USAF F-111 fleet with a single type. While the old TFR had an MTBF around 20 hours, MBTF for the AN/APQ-171 is better than 50 hrs.[1]

Improved AN/APQ-162 TFR for RF-4C.[1]

for the MH-60K and MH-47E helicopters[1]

Improved AN/APQ-174 by Raytheon for CV-22[7]

K_u band terrain-following radar by Texas Instruments part of AN/AAQ-13[1]