Air Defense Identification Zone
From Wikipedia, the free encyclopedia
North America is surrounded by an area called the Air Defense Identification Zone (ADIZ), which is jointly administered by the United States and Canada. This area, which is almost exclusively over water, serves as a national defense boundary for air traffic. Any aircraft that wishes to fly in or through the boundary must file either a Defense Visual Flight Rules (DVFR) flight plan or an Instrument Flight Rules (IFR) flight plan before crossing the ADIZ. The pilot must have a transponder and a two-way radio while approaching and crossing the ADIZ. In the U.S., the FAA handles these requests; Transport Canada handles Canadian requests. Any aircraft flying in these zones without authorization may be identified as a threat and treated as enemy military aircraft. This has not yet occurred, although even civilian aircraft making a simple mistake will be intercepted by military fighter aircraft and forced to land.
 Washington D.C. ADIZ
In 2003 the U.S. created a temporary ADIZ around the Baltimore-Washington Metropolitan Area as a response to the September 11, 2001 attacks. The concept is to create a restricted zone for air traffic near strategically sensitive locations in the District of Columbia, such as the White House. This temporary ADIZ has created tension between the government and the pilots that fly in and around the ADIZ. Despite efforts by the FAA to inform pilots of the ADIZ there are still many unauthorized incursions by unsuspecting pilots. Many times the unfortunate pilot will get a military escort consisting of a Coast Guard HH-65C helicopter or a F-16 fighter jet to the nearest airport, followed by suspension and/or revocation of the pilot's certificates. There have been two highly publicized mishaps inside this ADIZ that led to the evacuation of the Capitol. One involved a plane carrying the Governor of Kentucky. The other, almost a year later, involved a Cessna 150 flown by a student pilot accompanied by a pilot who was not familiar with the ADIZ rules, using an outdated chart. Following this incident in 2005 Congress began considering legislation to make this ADIZ and other remaining post 9/11 temporary restrictions permanent.
Within the ADIZ is an even more sensitive zone designated the Washington DC Metropolitan Area Flight Restricted Zone (DC FRZ). The DC FRZ extends approximately 13-15 nautical miles (15-17 statute miles) around the VOR/DME located at the Ronald Reagan Washington National Airport. Flight within the FRZ is restricted to governmental, certain scheduled commercial and a limited set of waivered flights. Three general aviation airports (known as the "Maryland 3" or the "DC 3") are located inside the DC FRZ. The "Maryland 3" are College Park Airport (CGS), Washington Executive/Hyde Field (W32), and Potomac Airport (VKX). The status of College Park Airport's claim to being "the oldest continuously operating airport in the world" has come in to question as a result of these restrictions.
To operate an aircraft within the DC ADIZ a pilot must: (1) file a flight plan, (2) establish and maintain radio communications, and (3) Transmit (“squawk”) a discrete mode-C transponder code assigned by Potomac Traffic Control, that reports altitude to air traffic controllers. It is not necessary to obtain a Class Bravo airspace clearance to operate within the ADIZ; ADIZ operations are distinct and separate from any airspace clearances a pilot may receive, however a discrete transponder code is required to operate within the ADIZ, with or without a separate airspace clearance. A pilot may not, under any circumstances, squawk 1200 (VFR) within the ADIZ. An ADIZ flight plan must list one of the nine reference points as either the destination (if leaving the ADIZ) or the origin (if entering the ADIZ). Although, the NOTAM clearly states that explicit clearance is not required to enter the ADIZ once two-way communication is established and the pilot has set the discrete transponder code issued by Potomac Approach; in practice explicit clearance should always be obtained from Potamac Approach before entering the ADIZ to avoid any unpleasant events. Note: you do not have to fly to any of these nine reference points. Just pick the one closest to your desired flight path. While some of the nine reference points are obvious landmarks (e.g. ESN is Easton Airport) others like MAPEL and GOLDA are not even shown on the Baltimore Terminal chart. All nine are only shown on an IFR Low Altitude Chart and are official waypoints and should be in the Jeppesen database of an aviation GPS receiver or Flight Management System (FMS).
An alternative to dealing with Potomac Approach is to enter ADIZ between Marine Corps Air Facility Quantico (Airport code NYG) and Brooke VOR (BRV) below 3000'. As Quantico's airspace intersects the boundary of the ADIZ, Quantico ATC has the authority to issue discrete transponder codes. A pilot should keep in mind that Quantico ATC has limited hours of operations during the week, and is closed most weekends. When Quantico is closed, Potomac Approach must be contacted in the usual fashion.
Pilots' groups, led by the Aircraft Owners and Pilots Association (AOPA), have argued that the ADIZ is unnecessary and has a harmful effect on the economy of small airports and aviation-related businesses in and near the ADIZ. Pilots involved in law enforcement have described the ADIZ as a "major, unnecessary burden on pilots and air traffic controllers with almost no increased security benefit."  AOPA and other groups are hoping to persuade Congress to lift or ease the ADIZ restrictions from Washington airspace -- or at the very least to dramatically improve its operational aspects. Many have complained that the current situation creates operational and safety problems for pilots, leading to decreased safety and security overall.
In 2006 the FAA issued an NPRM  docket number 17005 concerning making the temporary rules permanent. Over 20,000 responses were received the vast majority of them in opposition to making the temporary rules permanent. There were two public hearings held by the FAA in the Washington D.C. area on the NPRM. All speakers were opposed to making the NPRM permanent. The FAA published transcripts of the public hearings.   The transcripts were later withdrawn from the public as they were alleged to contain Sensitive Security Information.
Allegedly, the reason for this was that one pilot pointed out that a terrorist could fly to Dulles International Airport, make a right-hand turn at the last minute, and be over downtown Washington, D.C. in four minutes. 
The ADIZ and operational procedures have been discussed in depth on two Washington DC area email lists, DCPilots (http://www.dcpilots.org/), and DCPilots-Yahoo (http://www.dcpilots.net/). AOPA has also posted operational procedures, and provides online training through the Air Safety Foundation.