Since the Act distinguishes officers from employees, the purpose of the Act is to circumscribe and define federal tort liability, and subsequent caselaw, only criminal law enforcement officers are within the Act's waiver of sovereign immunity; airport security officers are not within this group, as they merely perform administrative searches.
Dissent: Act unambiguously includes investigative officers; airport security are officers of the United States empowered to conduct searches for violations of federal law; these searches go far beyond the level of an administrative search.
http://www2.ca3.uscourts.gov/opinarch/153047p.pdf
Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Neither an authoritative statement of the law nor legal advice. Quick work.