What the record showsUAP Docket

Case study · CASE-085 · Air-defense radar alert / intelligence warning review

Montauk-Benton radar alert (September 1957)

Not assessedWhere Montauk AFS, New York (773d AC&W Sqn) and Benton AFS, Pennsylvania (648th AC&W Sqn); interceptors from Kinross AFB, Michigan and Truax AFB, WisconsinWhen 1957-09-20; follow-up to 1958-02-26

Case

Overview
On 20 September 1957 the Montauk AN/FPS-20 radar and later Benton radar reported anomalous returns, provisionally correlated as one track. NORAD/CONAD scrambled F-102s without confirmation; the matter was briefed to the White House, reviewed by the Intelligence Advisory Committee Watch Committee and circulated in FBI memoranda. USAF technical investigation attributed the returns to radar malfunction/interference and possible chaff or ECM.
Investigative phases
Sept 20 radar returns and scrambles; Sept 21 CIA/Watch Committee memorandum (Herbert Scoville Jr.); Sept 23-24 FBI memoranda (R. R. Roach to A. H. Belmont); Sept 25-26 NORAD radar tests at Montauk; Feb 26 1958 USAF technical summary.
Reported phenomena
Montauk return about 210 nm ESE at about 19:05:48Z, track BB-6, lost about 50 nm SE; technical report lists an average 5,400 knots over the plotted segment with an unreliable altitude estimate. Benton 19:17-19:26Z track estimated initially at 920 knots, correlated with BB-6 by controller assignment after an approximately 11-minute gap.
Public evidence status
High: FBI memoranda (FBI UFO Part 16), CIA memorandum 0005516030 and Blue Book case 7228831 technical file. Low: original NORAD plot as a standalone archive file; no authenticated photograph of any object.
Alternative explanations / caveats
Montauk returns disappeared when the radar channel was changed and reappeared on the original channel (Sept 25-26 tests), supporting interference/malfunction. Benton returns appeared on one beam/scope with an unusual blip-to-scan ratio and were not confirmed by other beams or neighbouring sites; SAC chaff was reported in the area. The USAF concluded the data were unrelated or contradictory, but no single mechanism is proven for every return. The Montauk-Benton correlation was an assignment, not demonstrated continuity. Apparent radar speeds are not a physical vehicle's speed. The Sparks/Mellon reconstruction (higher speeds, possible IFF) is a secondary interpretation.
Next research tasks
Obtain the original 52-frame Blue Book scan and unannotated NORAD plot; test the Sparks/Mellon reconstruction against the technical team's instrument and correlation analysis; verify Watch Committee and FBI memo wording from scans.
Last reviewed
2026-11-12

Assessment

Not yet in the Case Assessment Matrix.

Evidence (10)

Documents gathered (10 lines of evidence)

4 readable here · 6 with a linked primary record · 0 still need a document · All cases on the evidence map

On the timeline (3)

  • 1957-09-20 Montauk and Benton radars report anomalous returns; F-102 scrambles without confirmation Reported
    Attributed by USAF to radar malfunction/interference and possible chaff/ECM
  • 1957-09-21 Watch Committee judges Soviet involvement highly improbable Reported
    National-security review, not confirmation of a craft
  • 1958-02-26 USAF technical summary finds Montauk-Benton data unrelated or contradictory Reported
    No single mechanism proven for every return