The following employees are exempt from the hours of work and overtime pay provisions of the Act:

(a) A criminal investigator receiving availability pay under §550.181(a) of this chapter, as provided in 29 U.S.C. 213(a)(16));

(b) A pilot employed by U.S. Customs and Border Protection or its successor who is a law enforcement officer as defined in section 5541(3) of title 5, United States Code, and who receives availability pay under section 5545a(i) of title 5, United States Code.