Check Out The Crazy Radar That Lies Beneath The MC-130H Combat Talon II's Gonzo Nose

This radar offers capabilities missing on the newer MC-130Js, which is why the H models remain in service years after their intended retirement date.

The nose radome of an MC-130H Combat Talon II opened for maintenance.
USAF capture

The U.S. Air Force's 1st Special Operations Wing has released video footage of various routine maintenance tasks on an MC-130H Combat Talon II special operations transport that includes a look inside the aircraft's giant nose at its powerful AN/APQ-170 radar. The AN/APQ-170 is the reason for the MC-130H's unique snout, which makes it quickly distinguishable from other C-130 variants. It's also offers robust terrain-following and terrain avoidance capabilities that all but two of the newer MC-130J Commando II's lack, a glaring issue the War Zone has reported on in detail in the past, which is why the Combat Talon IIs remains in service at all nearly a decade after the type's original sunset date.

The video, which the 1st Special Operations Wing posted on the Defense Visual Information Distribution Service website on Dec. 30, 2019, shows members of the 901st Special Operations Maintenance Squadron working on the AN/APQ-170 radar, navigation system, and communications equipment on an MC-130H, serial number 89-0282, at Hurlburt Field in Florida. The 901st's specific job is to train maintenance personnel to work on the Combat Talon IIs, 18 of which remain in service. Those aircraft are assigned to the 15th Special Operations Squadron, an operational unit, and the 19th Special Operations Squadron, which is responsible for training new aircrews for MC-130H and J models, as well as AC-130 gunship variants.

The highlight of the clip is definitely seeing MC-130H's nose radome open, which is done by unhooking various latches and then sliding it forward along an integral rail assembly inside. 

The entire nose assembly is massive compared to one found on a standard C-130H Hercules airlifter, or any other cargo-carrying C-130 variant for that matter, and is much bigger even than the one on its predecessor, the MC-130E Combat Talon. The Combat Talon was the Air Force's first dedicated special operations transport variant of the venerable C-130. 

Even with the extra room, the AN/APQ-170 fits snugly inside. The radar has seen a number of upgrades and modifications to improve its performance and reliability, but the general configuration remains largely the same. The system includes an X-band array mounted on top of two oscillating Ku-band arrays. As a mechanically scanned radar, the pair of dishes moving back and forth below helps the entire system scan faster than it would with just a single array. In the video clip, the personnel from the 901st are seen preparing to replace the X-band component.

USAF

A complete AN/APQ-170 radar undergoing maintenance. The X-band component on top and the Ku-band components below are clearly visible.

The result is a multi-function radar suite than can provide traditional navigation and weather detection capabilities, as well as terrain following and mapping functionality. That latter of these modes, which allows for low-altitude penetration in any weather, are absolutely critical for the MC-130H's core mission of providing a platform that is able to fly into denied areas in order to insert, extract, or resupply special operations forces. 

The Air Force has been exploring the possibility of acquiring a more survivable platform, such as a stealth transport aircraft, to perform this mission in the face of increasingly dense and capable hostile air defenses. The service has also explored major modifications to its various MC-130 variants to ensure they remain as relevant as possible in the future. You can read about these developments in this past two-part War Zone feature.

However, to remain as hidden from hostile air defenses as possible in the meantime, the Combat Talon IIs fly operational missions at night and at extremely low, nap of the earth altitudes, while following routes that exploit terrain features in order to further mask their approach. This requires a very capable and reliable radar with terrain-following and terrain-avoidance capabilities, such as the AN/APQ-170. The MC-130Hs also have a sensor turret with electro-optical and infrared cameras underneath the nose that provides additional situational awareness.

Carlos Menendez San Juan via Wikimedia

An MC-130H Combat Talon II. The aircraft's sensor turret is visible under its large nose radome, which houses the AN/APQ-170 radar.

As important as the AN/APQ-170 is to the Combat Talon II, it almost didn't come to be. The Air Force had hoped to avoid the cost of internally developing a specialized terrain-following and terrain avoidance capable radar, as it had done with the MC-130E. It had gone so far as to stop production of the AN/APQ-122(V)8 found on the Combat Talon, which, by the 1980s, cost between $8 and $10 million apiece, or between $19 and nearly $24 million in 2019 dollars, according to The Praetorian STARShip: The untold story of the Combat Talon, an official Air Force historical monograph. 

Adrian Pingstone via Wikimedia

An MC-130E Combat Talon with its own distinct nose radome housing the AN/APQ-122(V)8 radar, which is still notably smaller than the one on the MC-130H. 

The Air Force wanted a cheaper radar and hired IBM to build it. IBM, in turn, subcontracted the work to Emerson Electric, who developed what became the AN/APQ-170. The radar program ran into so much trouble it almost scuttled the MC-130H project entirely. With no alternative immediately available, the service decided to push ahead with the Emerson Electric product, delaying the entry into service of the first Combat Talon II until 1991. At that time, each radar cost $20 million, equivalent to nearly $38 million today, according to The Praetorian STARShip. As such, the radar alone accounted for more than a tenth of the each MC-130H's $160 million unit cost.

Difficulties in acquiring AN/APQ-170s and spare parts to go with them, together with continuing reliability issues, plagued the MC-130Hs in their early years. The Air Force initially took delivery of the Combat Talon II seen in the recent maintenance video, serial number 89-0282, in 1994 without a functioning X-band component installed. The radome also presented problems, particularly in not keeping everything warm enough to prevent icing in cold weather.

Despite updates and modifications, including a new radome heating and anti-icing system, by the mid-1990s, Praetorian STARShip says that the Air Force had completely given up on its requirement for the AN/APQ-170 to work for an average of 191 hours without a major failure. By the end of the decade, the service had initiated plans for yet another upgrade program, resulting in what was known as the AN/APQ-170(V)1-425 configuration, which had a so-called "mean time between failure" rate of 75 hours. By around 2000, all MC-130Hs had received this new version of the radar.

Mike Freer via Wikimedia

An MC-130H seen in 1999.

Given this experience, it seems somewhat curious that the Air Force has ended going down a similar route, with similar results, when deciding on the radar for the new MC-130J Commando II. This new special operations transport version of the C-130 uses the same AN/APN-241 multi-function radar as the standard C-130J airlifter, which provides some nominal amount of terrain-following and terrain avoidance capability. 

You can read more in detail about the MC-130J's own radar saga in this past War Zone piece, but suffice to say, testing showed that the AN/APN-241 was unsafe to use for the kind of extreme low-level flying the Air Force Special Operations Command conducts with its MC-130Hs. There is now a program in the works to add a dedicated terrain-following and terrain avoidance capable radar, the AN/APQ-187 Silent Knight, to the Commando IIs. As of May 2019, there were only two MC-130Js in testing with the new radar fit.

Lockheed Martin capture

An MC-130J Commando II with the AN/APQ-187 seen with its black radome mounted on top of the aircraft's nose.

The Air Force had planned to retire the Combat Talon IIs entirely by 2012, but has significantly slowed this process in light of the limited capabilities of the Commando IIs. The plan now is to retain at least some MC-130Hs until the Silent Knight-equipped MC-130J proves it can match its capabilities and there are sufficient numbers of those aircraft to meet the demands of the U.S. special operations community. 

As such, the MC-130Hs and their complex and expensive AN/APQ-170 radar, which have now been in service for nearly 30 years and are some of the oldest special operations aircraft in U.S. military service at present, look set to continue flying demanding, super-low-level, night-time special operations missions for at least a few more years.

Contact the author: joe@thedrive.com