Supporters of 20-year-old Deshon Marman claim the airline was racially profiling the man when the crew ordered him off a flight in June.
US Airways says Marman was arrested for not following orders after an employee told him to pull up his pants. The airliner says the demand was not due to his race.
The San Mateo County District Attorney's office dropped all charges against Marman.
Marman's attorney says his client plans to sue the airline.