Various NATO members have donated over 60 M109A6 and A7 155mm self-propelled howitzers to Ukraine. The first of these arrived in early 2022 and more have followed. Some M992A2 ammunition resupply vehicles, each carrying about a hundred 155mm shells were also sent to Ukraine along with and five M88A2 ARVs armored recovery vehicles. These last two are built on the same chassis as the M109.
The M109A7 is a major upgrade and uses the same chassis as the M-2 Bradley infantry fighting vehicle plus a new engine control system. Added to that are the cab and gun mounts from the original 1960s M109. The A7 also has an automatic rammer, but not a more complex automatic loader. Crews still have to manually load the propellant and 41 kg shell, but the semi-automatic rammer will then push the propellant and shell into the firing chamber and close the breech. Automating this part of the process improves accuracy somewhat because, when troops manually shoved (rammed) in the propellant and shell, they often applied too much or too little pressure and left the shell out of position by a tiny bit, just enough to hurt accuracy. The A7 also got new electronics, and numerous small improvements, many based on user suggestions. Not all the proposed upgrades were implemented immediately, but enough of them were to satisfy M109 users. The M109A7 made Paladin competitive with some new European self-propelled 155mm howitzers. The A7 is also heavier, at 35 tons and the new chassis can support up to 50 tons. Even at that weight, A7 is as fast as the existing M-109 and more maneuverable.
The M109A7 is also referred to as the M106A6 PIM for Paladin Integrated Management program. The first M109 entered service in 1963 and it proved so successful that it was ultimately adopted by most NATO countries and dozens of other nations as well. Including the many foreign license-built models, about 9,000 have been built so far. About a dozen nations still use it, often as improved models that were only used by the nation that developed a particular upgrade.
NATO provided training for 635 Ukrainian artillerymen as the M109A7 began arriving in Ukraine. For over a year now the M109A7s have been a key weapon in Ukrainian offensives and often moved to provide extra artillery support to halt Russian offensives.
During 2023 armed FPV (First Person View) UAVs (Unmanned Aerial Vehicles) began to appear in large numbers and were more effective at finding and destroying distant targets than mobile artillery systems. As the number of these UAVs increased, the need for M109A7s declined. The FPV UAVs were cheaper than artillery shells and able to find targets and then immediately attack, and usually destroy them. The FPV UAVs were manufactured locally by Ukrainians, often for friends or family members in the military. These locally made FPV UAVs were shipped, without explosives, to men in the military. The soldiers added the explosives and tended to use the FPV UAVs quickly. These unique weapons have been used by both sides, but the Ukrainians came up with the idea and are producing more of them than the Russians. The Russians prefer to develop new electronic jamming equipment to disrupt the control signals going to FPV UAVs. To deal with that the FPV UAV is programed to continue going after a selected target if jammed, or automatically return to where the sender was. More elaborate FPV UAV guidance systems will switch to another frequency if jammed. Another FPV UAV is that the operator can record a video of an attack to show their commanders or Ukrainian media how the Russians are being attacked.
Russia quickly copied the FPV UAV concept and massed produced FPV UAVs for use in Ukraine. Now these deadly weapons are the major source of casualties on both sides. Anyone who is attacked is particularly vulnerable. The Russians are planning a number of major offensives involving lots of troops and FPV UAVs will be used by attackers and defenders. The attackers will be more vulnerable and out in the open. FPV UAVs are vulnerable to machine-gun fire, and some will be lost. Most of the FPV UAVs will reach their targets and, if the troops being attacked don’t take cover, they will be wounded or killed.