What type of maintenance is performed on equipment above the Combat Aviation Brigade?

The correct answer is that all maintenance is performed on equipment above the Combat Aviation Brigade. This is because the term "all maintenance" encompasses various levels and types of maintenance activities required to ensure that equipment remains operational and in good repair.

In the context of military aviation, maintenance can include preventive measures, repairs, inspections, and modifications. Equipment above the Combat Aviation Brigade must undergo thorough maintenance to ensure operational readiness and safety, which involves not just routine checks but also more extensive servicing and repair efforts.

Therefore, stating that all maintenance is performed reflects the comprehensive nature of the maintenance support structure in place above the brigade level, including both aerial and operational maintenance as necessary. It captures the full spectrum of activities essential for sustaining aviation assets within a military context.