Unlike other modern military fixed-wing aircraft, the AC-130 relies on
visual targeting because its large profile and low operating altitudes of
approximately seven thousand feet, two thousand one hundred meters make it
an easy target its close air support missions are usually flown at night.
The u.s navy recently announced that a team of its engineers had crafted an
improved 105 millimeters Howitzer for use on the us air force's AC-130
gunships, that services remaining fleets of AC-130W stinger 2 and AC-130J
Ghost Rider aircraft are currently armed with a modified version of a
howitzer the us army first began fielding in the 1960s and that is no longer
in operational use anywhere else in the us military.
Engineers from the naval surface warfare center dahlgren division also known
as nswcdd or just dull brand located in virginia led the project to develop
a replacement for the modified M102 howitzers on air force AC-130Ws and
AC-130Js.
According to a press release that naval sea systems command nafsia put out
earlier this month, that team successfully built and delivered at least one
prototype of that weapo. The navy's release refers to this howitzer only as
the Gun Aircraft Unit (GAU)
GAU is just a standardized prefix in a joint air force navy designation
system that is typically used for guns intended to be mounted on aircraft.
For example the 30 millimeters bushmaster ii cannons that the Ac-130W and
AC-130J gunships are also armed with are designated under the same system as
GAU-23/S.
It is unclear whether dahlgren's howitzer is entirely new or if it
incorporates components from the M102. The navy describes it as upgraded and
a picture of the prototype seen at the top of this story and below, does
have some general features including a top mounted recoil system in common
with the older army howitzer.
The previous iteration of the AC-130s 105 millimeters gun system comprised
the M102 Howitzer and M137 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 nazia's release.
The upgrades to the 105 millimeters 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. This has become a much more
reliable system with less maintenance.
Matthew Buckler the gun weapon system lead mechanical engineer on the
project at dahlgren said in a statement, If we can get a system that's more
reliable that's more repeatable that works and that allows the war fighter
to complete their mission every time that's a huge benefit for the war
fighter.
The army's rock island arsenal designed and built the m102 in the early
1960s as a lightweight replacement for the World War II era M101 with the
first examples being delivered to units in 1964.
It eventually became the service's standard 105 millimeters howitzer a roll
it held until the newer m119 was fielded, starting in 1989. It saw major use
during the Vietnam war as well as with army units in various conflicts after
that including the american intervention in grenada in 1983 and the first
gulf war in 1990 to 1991.
The last known employment of m102s in their normal indirect fire role was in
2004 when an Arkansas army national guard field artillery battalion deployed
with these weapons to support operations in Iraq. Various american allies
and partners around the world continue to use these weapons.
In 1970 the air force had first begun testing a modified version of the M102
as a new weapon for its AC-130 gunship as part of a program called pave
aegis. The service began integrating those weapons onto a number of AC-130E
aircraft the following year, examples of which were subsequently employed in
combat in southeast asia.
The 105 millimeters howitzer became a standard weapon on all subsequent
AC-130H and AC-130U aircraft. The air force did not initially plan on
integrating the howitzer onto newer AC-130W sand AC-130J aircraft, placing a
greater emphasis on precision guided munitions and reducing the gun armament
to a single 30 millimeters GAU-23/A cannon.
However the M102 offers distinct capabilities compared to precision guided
bombs and missiles particularly in its ability to quickly focus a
significant amount of firepower on relatively small target areas and then
rapidly shift focus to new ones.
The Howitzer can also fire different types of ammunition, including air
bursting rounds giving it added flexibility against different target sets.
The GAU-23/A could offer some of this same operational flexibility.
However the destructive power of its 30 millimeter shells is nowhere near
that of an 105 millimeters round which can be used to reduce structures and
other obstacles engage hardened targets such as bunkers and take out armored
vehicles, among other things.
In the end the air force changed course and add the M102 to the stinger twos
and ghost riders as part of an upgrade package for both types. The issue of
course is that the M102 is a dated design that is no longer in production or
active use anywhere else in the us military and it has a steadily dwindling
user base abroad.
All of this makes sustaining a relatively small number of these guns for use
on the air force's AC-130s an increasingly costly and complex affair. This
is not the first time the air force has faced a similar issue with regards
to aging weapons on its AC-130s.
The AC-130U all of which have now been retired was the last platform of any
kind in the u.s military to be armed with the 40 millimeters bofors cannon.
before those aircraft were finally retired it became costlier and costlier
to source spare parts and ammunition for those guns, leading the air force
to scour arms dumps abroad for barrels and to refurbish stocks of World War
II aeroshells.
Why the navy was chosen to develop this improved 105 millimeters gun system
for the air force's AC-130s is unclear. This could be due in part to the
navy's general experience with very large caliber guns that are designed to
be fired accurately from platforms, ships, potentially moving quite
violently in multiple directions at once.
Whatever the case, dahlgren certainly has extensive past experience on
programs related to the AC-130, including supporting the past development of
the 105 millimeters howitzer package for the AC-130 and AC-130J and a
current project to integrate a laser-directed weapon on AJ model gunship.
