The study aimed to investigate the efficacy of blue light therapy to improve behavioral alertness in flight crew-members. Western Michigan University, College of Aviation, Jeppesen (a Boeing Company), Nature Bright Company, Airline participants, and a leading sleep researcher Schoutens, A.M.C. of FluxPlus, BV, The Netherlands, collaborated to examine whether timed blue light could improve flight crewmember alertness. During the four week study, crewmembers wore actigraph bands to monitor sleep behaviors. Self-assessed levels of sleepiness were recorded using the Karlosinska Sleepiness Scale (KSS), and self-assessed fatigue was measured using the Samn-Perelli (SP) fatigue scale. Participants completed psychomotor vigilance tests (PVT) to measure behavioral alertness. On the third and fourth weeks of the study, participants were exposed to blue light with short wavelength (465nm blue) light therapy. The results show that there was a significant difference in alertness between pre-intervention and post-intervention for each crew member and that 39.1% of the variance is explained by time (pre/post intervention). There is also a significant difference in alertness between flight crew and cabin crew and 49.4% of the variance is explained by position (flight/cabin crew).