Following the terrorist attacks of September 11, 2001, the airspace around Washington DC underwent a number of changes designed to restrict flying around the city.
In 2003, a temporary flight rules area was created and was named the Washington DC Air Defense Identification Zone.
[1] In order to fly within the DC SFRA, pilots of general aviation aircraft are required to file a special flight rules flight plan, obtain a discrete transponder code, and remain in contact with air traffic control at all times.
Los Angeles International Airport is surrounded by extensive Class B airspace, which is difficult for VFR traffic to navigate.
In particular, the airport has four large runways running east/west that have airspace protection from 10,000 feet (3050 metres) down to the surface that is 25 statute miles wide (40 kilometres).
[4][5] On November 19, 2009, the FAA effected an SFRA in the New York City Class B airspace, motivated largely by the mid-air collision of a private general aviation aircraft and a sightseeing helicopter ride along the Hudson River VFR corridor in the summer of 2009.