The M109 has a crew of six ... of the hull door is a large spade that is manually lowered to the ground before firing. They are normally deployed only when firing top charges.

The M109 howitzers were introduced into service ... the crew consisted of only three people, and the new system's firing range reached 25 miles (40 km), comparable with the leading artillery ...

Among the latest additions are U.S.-made M109 self-propelled howitzers. A recently released video from Ukraine’s Ministry of Defense showcases artillery crews training on these iconic weapons.