((a)) A permanent professor of the Academy who is the head of a department of instruction, or who has served as such a professor for more than six years, has the grade of colonel in the Air Force or the Space Force. However, a permanent professor appointed from the Regular Air Force or the Space Force has the grade of colonel after the date when such person completes six years of service as a professor, or after the date on which such person would have been promoted had such person been selected for promotion from among officers in the promotion zone, whichever is earlier. All other permanent professors have the grade of lieutenant colonel in the Air Force or the Space Force.
((b)) A person appointed as director of admissions of the Academy has the regular grade of lieutenant colonel in the Air Force or the grade of lieutenant colonel in the Space Force, and, after such person has served six years as director of admissions, has the regular grade of colonel in the Air Force or the grade of lieutenant colonel in the Space Force. However, a person appointed from the Regular Air Force has the regular grade of colonel and a person appointed from the Space Force has the grade of colonel in the Space Force after the date when such person completes six years of service as director of admissions, or after the date on which such person would have been promoted had such person been selected for promotion from among officers in the promotion zone, whichever is earlier.