Which of the following is not included in the rated aircrew inventory?

The rated aircrew inventory consists of personnel who are qualified and trained to perform as aircrew members in various capacities such as pilots, navigators, or other specified aircrew roles. The key distinction to note is that this inventory primarily includes officers who hold certain ranks that directly engage in flying operations and flight training.

Brigadier generals, being higher-ranking officers, generally transition out of direct flying roles and into more strategic or command positions, thus typically not being part of the rated aircrew inventory. In contrast, lieutenant generals, colonels, and captains can still hold active rated aircrew positions since they may either still be flying or managing operational aircrew activities.

Thus, the correct answer identifies brigadier generals as the rank that does not generally fit within the rated aircrew inventory, reinforcing the understanding of how role and responsibility change with rank within the armed forces.