An upgraded GM Type-C for ground combat. The Type-C itself is a mass produced mobile suit that attempted to rework the quality control of the GM which was mass produced with inferior quality early on, by improving compatibility of parts and correcting the performance differences of the suit. As a result of this, production and serviceability improved giving it a slightly enhanced performance.

In response to ground combat, the GM Ground Type-C was subjected to upgrades such as dustproof treatment that focused on the joints, modification to the soles and the loading of a new type of backpack. Part of the changes can also be seen in the other GM type mobile suits that were upgraded for ground combat, making it evident that compatibility was maintained.

Units affiliated with the assault carrier Spartan were deployed in Operation Thunderbolt. Many participated in the marine/aerial battle during the invasion of the South Seas Alliance territory and engaged the South Seas Alliance border garrison from aboard the Spartan and with the landing craft. Units on the Spartan were equipped with assault rifles for mid-range interception while the units deployed on the landing craft over the sea were equipped with long range beam rifles and missile launchers for long-range attacks.

As the Spartan struggled with the South Seas Alliance deployment of smoke curtains and chaff and their Gouf and SFS Do-dais with semi-flight abilities, a single unit demonstrated frenzied movement. Its pilot was Io Fleming.

Io, who saw his childhood friend Claudia Peer with the enemy when she should’ve been dead, rushed out into battle in a GM Ground Type-C since his Atlas Gundam was undergoing repairs. Io kicks a Gouf off the deck of the Spartan that the Gundam Ground Type-S units were struggling with before shifting the battle to the skies with help from Biance Carlisle piloting a Corvette Booster. Using jumps and melee attacks while docking with the Corvette Booster, he shot down the Do-Dai teams. In the end, he was caught by a Gouf’s heat rod, but he proved the potential that the suit could approach a Gundam type.

The arms and lower half of the body are almost the same type as other Ground type GMs (including Ground Combat Gundams), and a complete streamlining of parts can be seen. Standardization was also attempted for the smaller backpacks to be equal with the larger ones. The large-sized backpack is a new model, whose specs emphasize propulsion functions but it does not have a large diameter/multi-nozzles like the ones used on the Ground Gundams.

The standard armaments on the Spartan are an assault rifle, beam saber and shield. The assault rifle is the same type that the Atlas Gundam is equipped with. The long range beam rifle and missile launcher were utilized by the units on board the landing craft during the battle with the South Seas Alliance border garrison. While they should’ve been able to attack from long ranges from atop the ocean, smoke screens and chaff prevented them from doing so.