The Royal Manticoran Army Atmospheric Command was a unit of the Royal Manticoran Army.
It was responsible for both atmospheric and near-space security for the planets of the Star Kingdom and Star Empire of Manticore, and so it could effectively be thought of as the "Royal Manticoran Air Force". (infodump)
Atmospheric Command operated all of the Army's aerospace fighters and transports, and was organized into squadrons and wings. Its personnel routinely trained in joint operations with the Royal Manticoran Navy and Royal Manticoran Marine Corps.[1]
Under the terms of the East Cay Agreement, the Atmospheric Command was prohibited from operating extra-atmospheric vehicles at "interplanetary distances", which was interpreted to mean more than one light-minute from a planetary body. (Companion)