The Black Triangle Aircraft: Secret Planes, UFOs, and the TR-3B Myth.
It is one of the most consistent shapes in modern UFO reporting: a large, dark, silent triangle, gliding low and slow across the night sky, a light at each corner. Since the 1980s, tens of thousands of people in several countries have reported seeing one. The reports are real; the explanations run from the mundane (a formation of ordinary aircraft, a blimp, a misjudged distance) to the secret (a classified military program) to the fantastical (an antigravity spacecraft called the TR-3B that exists only on the internet).
AnomalyDesk is reader-supported. Articles may contain affiliate links to books and primary-document collections. Read our full funding disclosure.
What the black-triangle reports are, in a paragraph.
“Black triangles” are a category of UFO/aircraft report, prominent since the 1980s, describing large, dark, often silent triangular or boomerang-shaped craft, typically seen at night, moving slowly at low altitude, with lights at the corners and sometimes a central light. The shape has appeared in several major sighting waves — the Belgian UFO wave of 1989–1990, the Hudson Valley sightings of the 1980s, and numerous reports across the U.K. and U.S. — and is among the most-reported UFO forms of recent decades. The reports invite three broad explanations. The first is conventional misidentification: a formation of ordinary aircraft (each light a separate plane) perceived as a single object, a slow-moving airship or blimp, advertising aircraft, or aircraft seen at night with distance and motion misjudged. The second is classified military aircraft: the era of black triangles coincides with the development and deployment of stealth aircraft (the F-117, the B-2 Spirit bomber — itself a large flying-wing/triangular shape — and various reconnaissance and prototype programs), and many researchers, including some skeptical of the UFO interpretation, attribute a portion of credible triangle reports to secret aircraft. The third is the exotic/UFO interpretation, which holds that at least some triangles are not conventional craft at all. A specific and influential strand of this is the “TR-3B” legend: the claim, originating in the 1990s with figures like Edgar Fouché, that the U.S. operates a large triangular antigravity spacecraft (the “Astra”) using a mercury-based plasma reactor and reverse-engineered technology. The TR-3B has no credible documentary or physical support and is regarded as an internet-era hoax/legend, though it is widely repeated. The documented reality is that black-triangle reports are a genuine and consistent phenomenon with multiple causes: many are explicable as conventional aircraft, formations, or misperception; some credible cases plausibly involve classified military aircraft (whose secrecy the government has reason to maintain); a residue remains unexplained; and the specific TR-3B antigravity claim is unsupported. The case sits at the intersection of the UFO and conspiracy pillars because it mixes a real perceptual/sighting phenomenon with both legitimate secret-aircraft speculation and unfounded exotic-technology mythology.
The documented record.
The consistent shape and the waves
The reports are real and recurrent. Verified Triangular-craft reports are among the most common modern UFO descriptions, featuring in major waves including the Belgian wave (1989–1990) and the Hudson Valley sightings (1982–1989), and in continuing reports worldwide. The consistency of the described shape is a genuine feature of the data [1][2].
The conventional explanations
Many cases have mundane causes. Verified Investigations of triangle waves have attributed numerous sightings to formations of conventional aircraft (where corner lights are separate planes), to slow airships and advertising blimps, to aircraft misperceived at night, and to other ordinary sources. The Hudson Valley wave, for instance, was substantially attributed to a group of pilots flying ultralight aircraft in formation (the “Stormville Flyers”), and the famous Belgian wave's most iconic photograph was admitted to be a hoax in 2011 [1][2][3].
The classified-aircraft hypothesis
The era coincides with real stealth development. Verified The rise of black-triangle reports coincides with the development and fielding of low-observable (stealth) aircraft, including the angular F-117 Nighthawk (operational secretly in the 1980s) and the large flying-wing B-2 Spirit bomber (revealed 1988), as well as various classified prototypes and reconnaissance programs. Many researchers attribute a portion of credible triangle reports to such secret aircraft, whose existence the government concealed for years — a documented pattern of real classified programs underlying some “UFO” reports [2][4].
The TR-3B legend
The specific antigravity-craft claim is unsupported. Verified The “TR-3B Astra” — a large triangular antigravity spacecraft allegedly using a mercury-plasma reactor — originates principally with Edgar Fouché in the late 1990s and circulates widely online. It has no credible documentary, physical, or engineering support; the described physics (a rotating mercury-based antigravity field) is not established science, and no evidence of such a craft exists. It is generally classified as an internet hoax/legend rather than a documented program [4][5].
The unexplained residue
Some reports resist explanation. Verified As with UFO reports generally, a portion of credible triangle sightings — including elements of the Belgian wave, where the Belgian Air Force scrambled F-16s and reported radar contacts — remain officially unexplained, without that meaning they were exotic craft. The Belgian military's candid “we cannot explain the phenomenon” coexists with the later hoax admission for the famous photo and with conventional explanations for many reports [1][3].
The competing positions.
The exotic/UFO position holds that black triangles are genuine unknown craft — extraterrestrial or exotic — with the TR-3B as a specific (secret human antigravity) variant. Claimed It points to the shape's consistency, the silence, and the slow flight as evidence of non-conventional technology [5].
The skeptical/mainstream position is that black-triangle reports are a mixed phenomenon: many are conventional aircraft, formations, airships, or misperception; some credible cases plausibly reflect classified military aircraft developed during the stealth era; a residue is unexplained without being exotic; and the TR-3B specifically is an unsupported internet legend. Disputed The legitimate, interesting core — that some triangle reports may correspond to real secret aircraft, which is consistent with the documented history of classified programs — is distinct from the unfounded antigravity claim. This archive treats the reports as a genuine phenomenon with multiple mundane and possibly classified-aircraft causes and an unexplained residue, and the TR-3B as a debunked legend [2][4][5].
The unanswered questions.
Which classified aircraft, if any
If some triangles are secret aircraft, which programs they correspond to is, by the nature of classification, not publicly established. Unverified The attribution to “classified aircraft” is plausible but specific identifications are not public [2][4].
The unexplained cases
The residue of credible, unexplained triangle reports (e.g., parts of the Belgian wave) has no agreed explanation. Disputed Unexplained does not mean exotic, but the specific causes are unknown [1][3].
The origin and spread of the TR-3B
Why the unsupported TR-3B claim became so widespread is a question about internet legend formation rather than aerospace. Disputed Its appeal lies in fusing real stealth secrecy with science-fiction physics [4][5].
Primary material.
The accessible record on black triangles is held principally in these sources:
- The major wave investigations — the Belgian UFO wave (SOBEPS and Belgian Air Force records) and the Hudson Valley investigation (Hynek, Imbrogno, Pratt).
- Aviation-history documentation of stealth aircraft (F-117, B-2) and classified programs, for the secret-aircraft hypothesis.
- The TR-3B source material — Edgar Fouché's claims — and the skeptical analyses debunking it.
- UFO-report databases documenting the frequency and consistency of triangle reports.
- The Belgian-wave hoax admission (2011) for the famous photograph.
Critical individual sources include: the Belgian and Hudson Valley wave investigations; aviation histories of stealth aircraft; and the TR-3B debunking literature.
The sequence.
- 1980s The F-117 and B-2 stealth aircraft are developed secretly; black-triangle reports rise.
- 1982–1989 The Hudson Valley wave; many sightings attributed to ultralight formations.
- 1989–1990 The Belgian UFO wave of triangle reports; F-16 scrambles.
- Late 1990s Edgar Fouché introduces the TR-3B antigravity claim.
- 2011 The famous Belgian-wave triangle photograph is admitted to be a hoax.
- Present Triangle reports continue; explanations remain mixed.
Cases on this archive that connect.
The Belgian UFO Wave (File 052) and the Hudson Valley Wave (File 124) — the major triangle waves, with their conventional and unexplained components.
The Aurora Aircraft (File 118) — another classified-aircraft legend at the secret-plane/UFO boundary.
The Phoenix Lights (File 048) — a V-formation case frequently linked to the triangle phenomenon.
The Bob Lazar Claims (File 157) — another exotic-craft claim resting on non-credible sourcing.
More related files coming as the archive grows. Planned: the B-2 and stealth programs, and the Phoenix Lights flare explanation.
Full bibliography.
- SOBEPS and Belgian Air Force records of the 1989–1990 Belgian UFO wave; the 2011 Petit-Rechain photograph hoax admission.
- Hynek, J. Allen, Imbrogno, Philip, and Pratt, Bob, Night Siege: The Hudson Valley UFO Sightings, 1987.
- Aviation histories of the F-117 Nighthawk and B-2 Spirit and classified-aircraft development.
- Fouché, Edgar, TR-3B claims; skeptical analyses debunking the TR-3B/Astra legend.
- UFO-report databases (e.g., NUFORC, MUFON) documenting triangle-report frequency.