S1 10 D-30
D-30s at Planina Airport in Episode 10.
Origin Soviet Union
Ammunition 122 mm
User Republic T military
Koko's Squad
Manga debut Chapter 26
Anime debut Episode 9

The D-30 is a 122 mm howitzer of Soviet design. It is used by the unnamed Asian army that Mao served with as well as the Republic T military. D-30 ammunition was delivered by Koko's Squad to Planina Airport in Autonomous Region X. Several D-30s were deployed at the airport.

Mao devised the idea of using a D-30 to fire a beehive round at the Balkan Dragons from an airborne Antonov An-12 to break out of the anti-aircraft cordon they would throw up around the airport. One of the D-30s was loaded onto the An-12 and secured. When the An-12 reached 10,000 feet, Mao opened the cargo door and fired a beehive round which wiped out the Dragons on the ground with flechettes before they could fire a second salvo of SA-9s.