[NASA Employees' Claims for Commercial Air Fares]

A National Aeronautics and Space Administration (NASA) certifying officer requested a decision concerning several NASA employees' reimbursement claims for commercial air fares incurred when the employees delayed their departure from their temporary duty station to take annual leave. GAO held that the employees were personally responsible for the cost of their commercial air fares, since they did not travel by the mode of transportation authorized and took annual leave before returning from temporary duty. Accordingly, the claims were denied.