In the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 and United Kingdom

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, a black project is in the vernacular a classified military/defense project, unacknowledged publicly by the government, military personnel, and defense contractors. Examples of U.S. military aircraft developed as black projects include the F-117 Nighthawk

F-117 Nighthawk

The Lockheed F-117 Nighthawk was a single-seat, twin-engine stealth ground-attack aircraft formerly operated by the United States Air Force . The F-117A's first flight was in 1981, and it achieved initial operating capability status in October 1983...

 stealth attack aircraft and the B-2 Spirit

B-2 Spirit

The Northrop Grumman B-2 Spirit is an American heavy bomber with low observable stealth technology designed to penetrate dense anti-aircraft defenses and deploy both conventional and nuclear weapons. The bomber has a crew of two and can drop up to eighty -class JDAM GPS-guided bombs, or sixteen ...

 stealth bomber, which were highly classified and denied to exist until ready to be announced to the public.

In the United States the formal term is Special Access Program

Special access program

Special access programs in the Federal Government of the United States of America are security protocols that provides highly classified information with safeguards and access restrictions that exceed those for regular classified information...

 (SAP).

Previously classified

• B-2 Spirit
  B-2 Spirit
  The Northrop Grumman B-2 Spirit is an American heavy bomber with low observable stealth technology designed to penetrate dense anti-aircraft defenses and deploy both conventional and nuclear weapons. The bomber has a crew of two and can drop up to eighty -class JDAM GPS-guided bombs, or sixteen ...
  
   stealth bomber
• Boeing Bird of Prey technology demonstrator
• F-117 Nighthawk
  F-117 Nighthawk
  The Lockheed F-117 Nighthawk was a single-seat, twin-engine stealth ground-attack aircraft formerly operated by the United States Air Force . The F-117A's first flight was in 1981, and it achieved initial operating capability status in October 1983...
  
   stealth ground-attack aircraft
• KH-11 KENNAN
  KH-11 Kennan
  The KH-11 KENNAN, renamed CRYSTAL in 1982 and also referenced by the codenames 1010, and "Key Hole", is a type of reconnaissance satellite launched by the American National Reconnaissance Office since December 1976...
  
   reconnaissance satellite
• SR-71 Blackbird
  SR-71 Blackbird
  The Lockheed SR-71 "Blackbird" was an advanced, long-range, Mach 3+ strategic reconnaissance aircraft. It was developed as a black project from the Lockheed A-12 reconnaissance aircraft in the 1960s by the Lockheed Skunk Works. Clarence "Kelly" Johnson was responsible for many of the...
  
   Mach 3.3 very high-altitude reconnaissance aircraft
• Lockheed CL-400 Suntan high-altitude, high-speed reconnaissance prototype
• Lockheed U-2
  Lockheed U-2
  The Lockheed U-2, nicknamed "Dragon Lady", is a single-engine, very high-altitude reconnaissance aircraft operated by the United States Air Force and previously flown by the Central Intelligence Agency . It provides day and night, very high-altitude , all-weather intelligence gathering...
  
   very high-altitude reconnaissance aircraft
• Lockheed Martin RQ-170 Sentinel
• Lockheed Martin Polecat unmanned aerial vehicle
• Northrop Tacit Blue
  Northrop Tacit Blue
  |-See also:...
  
  
• Operation Cyclone
  Operation Cyclone
  Operation Cyclone was the code name for the United States Central Intelligence Agency program to arm, train, and finance the Afghan mujahideen during the Soviet war in Afghanistan, 1979 to 1989...
  
  
• RQ-3 Dark Star
  RQ-3 Dark Star
  -See also:- Footnotes :ReferencesSources* Specifications and second and third paragraphs: Display information on exhibit at Museum of Flight in Seattle, Washington, US.- External links :* *...
  
   high altitude reconnaissance UAV

Currently classified, but speculated

• Misty and Enhanced Imaging System spy satellites
• X-41 Common Aero Vehicle
  X-41 Common Aero Vehicle
  X-41 is the designation for a still-classified U.S. military spaceplane. Specifications or photos of the program have not been released to the public yet; as a result not much is known about its goals...
  
   military spaceplane
• SR-72 stealth reconnaissance UAV
• Aurora hypersonic spy aircraft (unconfirmed)
• Area 51
  Area 51
  Area 51 is a military base, and a remote detachment of Edwards Air Force Base. It is located in the southern portion of Nevada in the western United States, 83 miles north-northwest of downtown Las Vegas. Situated at its center, on the southern shore of Groom Lake, is a large military airfield...
  
  
• Stealth Blimp Reconnaissance platform