PHILADELPHIA (WPVI) -- A ground stop at Philadelphia International Airport on Tuesday has been lifted as of 9:21 a.m.The FAA issued it just after 8:30 a.m. due to cloud cover.Travelers are advised to check with their airlines for the latest flight information.As of 9:30 a.m., there have been 50 flight delays and 10 cancellations, according to FlightAware. Report a correction or typo