Our First Look At An AC-130J Ghostrider Gunship’s New 105mm Gun

Photos from a recent event at Cannon Air Force Base, New Mexico, provide our first look at a U.S. Air Force AC-130J Ghostrider gunship equipped with an upgraded 105mm howitzer. This follows an announcement from the U.S. Navy earlier this year that it had delivered at least one prototype of a gun that is intended to replace the existing, aging M102 howitzers that have been used on various AC-130 gunship variants for decades now.

The new howitzer was seen installed on an Air Force AC-130J belonging to the 17th Special Operations Squadron during an “honorary commander flight event” for prominent members of the community from the nearby city of Clovis, New Mexico, held on August 24, 2022. Pictures from the ground tour and flight demonstration show these ‘honorary commanders’ standing next to the rear rear-left side of the aircraft’s fuselage, as well as inside, with the new gun clearly visible.

City of Clovis ‘honorary commanders’ receive a tour and safety brief on a U.S. Air Force 17th Special Operations Squadron AC-130J Ghostrider gunship during an honorary commander flight event on Aug. 24, 2022, at Cannon Air Force Base, New Mexico. The new 105mm howitzer is seen sticking out of the rear left side of the fuselage. USAF

It remains unclear how much, if anything, the Navy’s 105mm howitzer shares with the original M102. The Naval Surface Warfare Center Dahlgren Division previously described the weapon as being “upgraded,” rather than entirely new. The replacement design has also been referred to generically as a Gun Aircraft Unit (GAU), but its full designation is unknown.

A picture of an older M102, readily identifiable by the triangular section behind the flash hider, installed on an AC-130J gunship. USAF
A picture of one of the prototypes of the Naval Surface Warfare Center Dahlgren Division’s 105mm “GAU.” USN

The recent pictures AC-130J with the gun installed at Cannon make clear that the new design at least features a distinctly different recoil mechanism, which includes two cylinders side-by-side on top instead of a single one.

An ‘honorary commander’ and an AC-130J gunner with the 17th Special Operations Squadron firing the aircraft’s 105mm gun. The side-by-side recoil cylinders on top of the new 105mm howitzer are visible at the bottom left of this picture. USAF
A picture of an M102 howitzer inside an AC-130U gunship, showing the single recoil cylinder on top. USAF

In addition, the pictures of the prototype that the Navy released in January showed a threaded section on the front of the barrel that we now know is designed to accept a new style of flash hider.

A close-up image of the AC-130J’s howitzer. A flash hider has been attached to the end of the barrel. USAF
Engineers from the Naval Surface Warfare Center Dahlgren Division stand in front of a prototype of the new 105mm howitzer with an exposed threaded section at the muzzle end of the barrel. USN

“The previous iteration of the AC-130’s 105mm gun system comprised the M102 howitzer and M137A1 recoil mechanism, which are no longer supported by the Army, meaning that an upgrade was necessary due to obsolescence and advancements in technologies since the original recoil mechanism was designed,” according to a release from Naval Sea Systems Command in January. “The upgrades to the 105mm GAU are sweeping, however, the engineers at Dahlgren were careful to ensure that the functionality, accuracy, and usability of the weapon remain largely the same.”

“We’ve described [the development process] as peeling back an onion,” Matthew Buckler, an engineer at Dahlgren who helped develop the gun, had said in a statement included in the January release. “You get the most immediate issue and solve that one. Then when you solve that one, something else becomes more important and you kind of just keep peeling it back until you’ve essentially solved all of your major issues and you can live with whatever the maintenance interval may be.”

The Air Force had originally planned to forgo installing the M102, which first entered service as a towed howitzer with Army artillery units in 1964, on the AC-130J, as well as the preceding AC-130W Stinger II. The howitzer had been fitted to every new AC-130 variant before that, starting with a subvariant of the AC-130E, known as the Pave Aegis configuration, during the Vietnam War. However, by 2004, Air Force gunships were the only platforms anywhere in the U.S. military still employing the M102 in any form, and the weapons had become increasingly difficult to sustain.

A Vietnam War-era picture showing an M102 howitzer removed from an AC-130E Pave Aegis gunship.

So, the plan had been for the AC-130Js and Ws to be primarily armed with a variety of precision-guided munitions, along with a single GAU-23/A 30mm Bushmaster II automatic cannon. However, an 105mm howitzers offers distinct capabilities compared to guided missiles and bombs, as well as and smaller caliber guns, that are valuable in various situations against a variety of target sets.

For instance, the howitzer can bring a significant amount of firepower to bear on relatively small targets, whether they be bunkers or other obstacles, armored vehicles, or enemy forces in the open, and then readily shift its focus to new ones. The gun offers added flexibility by being able to fire different types of ammunition, including air-bursting rounds, from one shot to the next.

One of the ‘honorary commanders’ prepares to load a 105mm practice round into the howitzer onboard the AC-130J during the community engagement event at Cannon on August 24. U.S. Air Force photo.

The Air Force subsequently changed course and decided to integrate the M102 onto the AC-130J and AC-130W. The new Navy-developed design will help ensure that the Air Force’s gunships can continue to offer this kind of support for the foreseeable future.

The integration of this gun onto the AC-130J is perhaps doubly important given that the Ghostiders are moving ever closer to being the only gunships in service. The Air Force retired the AC-130U Spooky II in 2020 and it plans to have sent all of the AC-130Ws to the Bone Yard at Davis-Monthan Air Force Base in Arizona by the end of next year.

It is not immediately clear how many AC-130Js the Air Force has at present, but the service said in 2021 that expected to eventually acquire a fleet of 37 Ghostriders in total. The 17th Special Operations Squadron at Cannon received its first example last July.

It is similarly unclear how many of the AC-130Js that are in service now have the new 105mm howitzer. What appears to be a different AC-130J from the 17th Special Operation Squadron with the Navy-developed gun installed traveled to Hawaii earlier this month. This aircraft has a large version of the unit’s insignia painted just behind the cockpit on the left side of the fuselage, which does not look to be present on the Ghostrider that was made available for the honorary commander flight event.

An AC-130J Ghostrider gunship with the new 105mm howitzer from the 17th Special Operations Squadron at Kaneohe Bay, Hawaii, on August 17, 2022. USAF

It’s worth noting that the replacement howitzers are not the only new weapons that the AC-130Js are currently slated to receive. The Air Force took delivery of the first prototype of a solid-state laser directed energy weapon for the Ghostrider last year. U.S. Special Operations Command (SOCOM) said in May that the laser was still being tested on the ground. Actual flight testing is expected to begin next year. You can read more about the capabilities that this weapon could offer Ghostrider crews here.

In the meantime, the Air Force’s Ghostriders are already at least beginning to add new 105mm howitzers to their arsenals.

Contact the author: oliver@thewarzone.com

Oliver Parken Avatar

Oliver Parken

Associate Editor

Oli’s background is in the cultural and military history of twentieth-century Britain. Before joining The War Zone team in early in 2022, he was Assistant Lecturer at the University of Kent’s Center for the History of War, Media and Society in the U.K., where he completed his PhD in 2021. Alongside his contributions to The War Zone‘s military history catalog, he also covers contemporary topics and breaking news.