The FAA issues Temporary Flight Restrictions (TFR) in the form of a Notice to Airmen (NOTAM) which are effective for the duration of an event, typically a few days or weeks. TFRs are issued for VIP movement such as the president's travels outside Washington, D.C., surface-based hazards to flight such as toxic gas spills or volcanic eruptions, air-shows, military security, and special events including political ones like national party conventions.[18] TFRs have also been issued to ensure a safe environment for firefighting operations in the case of wildfires and for other reasons as necessary. A TFR was quickly issued around the crash site of Cory Lidle's airplane in New York City.