A Special VFR clearance allows a pilot to operate under Visual Flight Rules (VFR) in Class D airspace when the visibility is less than the standard requirements, specifically when visibility is at least 1 statute mile and the pilot can remain clear of clouds. This clearance is typically granted to enable operations during conditions that would otherwise require instrument flight rules (IFR). Pilots must also maintain visual reference to the ground and other aircraft.
1 mile visibility and clear of clouds.
1,000-foot ceiling and 3 miles visibility.
I don't think there are limits to how slow an aircraft can fly in any airspace.
By radar or GPS.
ATC clearance is authorization to proceed under specified traffic conditions in controlled airspace.
FAA TERPS stands for Terminal Instrument Procedures, a set of guidelines and procedures developed by the Federal Aviation Administration (FAA) to design and establish instrument flight procedures for aircraft. These procedures ensure safe navigation and landing at airports, especially in low visibility conditions. TERPS incorporates factors such as terrain, airspace usage, and obstacle clearance to create standard approach and departure paths for pilots. The goal is to enhance safety and efficiency in the terminal airspace environment.
There's no single answer for this. When a presidential aircraft moves, the government declares airspace restrictions. (If the airspace belongs to a country other than the one the president runs, that government will declare airspace restrictions as a diplomatic gesture.)
Airspace in the US is classified into the following categories: A, B, C, D, E, and G. The airspace is ordered from Class A-Tightest control to Class G-No control. Class A airspace is anywhere from 18000 feet to flight lever 600 (approx. 60000 feet); all aircraft in class A airspace must fly IFR (instrument flight rules) and stay in contact with ATC. The required separation is also greater in class A airspace. Class B airspace surrounds larger airports, and consists of 3 or more "shelves". Class B airspace looks somewhat like an upside down wedding cake. In Class B airspace, all aircraft require a specific clearance to enter or fly through the airspace. Class C airspace Surrounds smaller airports, and looks like an upside down cake with only two layers. Aircraft entering class C airspace need only establish two way radio contact with ATC before entering. Class D airspace has the same restrictions as class C, but has only one layer. Class E airspace encompass everything from 1200 feet to 18000 feet that is not Class B, C, D, or, G. Sometimes the base elevation is lower or higher that 1200 feet, but 1200 is the normal base. Class E also encompasses everything above Flight Level 600. VFR (visual flight rules) aircraft are not required to contact ATC in class E airspace. IFR aircraft maintain ACT contact in class E. Class G airspace is uncontrolled, and usually extends to anything below 1200 feet. Even IFR aircraft do not contact ATC in class G airspace.
Worse than that; the airspace over Washington DC is "prohibited". There are narrow corridors to get to Reagan National Airport, but the area over the White House and the Capitol are prohibited to any except military aircraft with clearance. Similar prohibited airspace is declared around Camp David, the Presidental retreat in the Maryland foothills, and over the President's vacation home. Violate this airspace and you WILL lose your pilot's license.
TCAS (Traffic Collision Avoidance System) is not specifically required in Class A airspace, but it is mandated for certain types of aircraft operating under instrument flight rules (IFR) in controlled airspace. Generally, commercial airliners and larger aircraft must be equipped with TCAS to enhance safety and provide alerts about potential mid-air collisions. While smaller aircraft may not be required to have TCAS, its use can significantly improve situational awareness and safety in busy airspace.
Military aircrafts don't disable their transponder beacon when flying in enemy airspace, they change the settings on it though.
The Lockheed U-2 flown by Gary Powers .