RB-47 1957 — an Air Force EW aircraft tracked UAP across four US states for 700 miles

On July 17, 1957, a US Air Force RB-47H electronic-warfare aircraft on a training mission out of Forbes AFB in Kansas tracked an unidentified aerial object — simultaneously on its own onboard ALA-6 electronic-intercept gear, on visual sighting by the crew, and on ground-based radar — across roughly 700 miles of flight covering parts of Mississippi, Louisiana, Texas, and Oklahoma. The incident is widely regarded by researchers, including the 1968 Condon Committee staff members who studied it, as one of the strongest multi-platform UAP cases in the American institutional record.

What the crew detected

The RB-47H carried a crew of six, including three electronic-warfare officers operating signals-intelligence equipment in the aircraft's specialised compartment. During the flight, the EW operators began receiving an unusual S-band radar signal at frequencies and pulse characteristics that did not match any known ground radar in the region. The signal moved relative to the aircraft in a way that ground radar could not, implying an airborne source. Shortly afterward, the pilot and copilot reported visual contact with a bright luminous object roughly off the left wing at a position consistent with the direction of the intercepted signal. Subsequently, ground radar at the Duncanville Air Defense site in Texas confirmed a return at the same approximate location.

Over the course of the next ninety minutes, the crew tracked the object as it changed position relative to the aircraft, briefly disappeared from all three sensor types simultaneously, and then reappeared on all three again at a new geometry. The crew estimated the object's altitude and velocity multiple times and reported manoeuvres consistent with an intelligent platform, not a propagation artefact or atmospheric phenomenon.

Why it stands out

The structural feature that distinguishes the RB-47 case from earlier multi-witness incidents is the simultaneous registration of the object on three independent sensor modalities — onboard electronic intercept, visual sighting by trained military aircrew, and ground-based primary radar — operated by different personnel using different equipment. The case therefore resists the most common skeptical mechanisms: misidentification by a single witness (ruled out by sensor correlation), radar propagation artefacts (ruled out by visual confirmation), and visual atmospheric optics (ruled out by radar correlation). Whatever the underlying phenomenon, the case is exceptionally difficult to attribute to any single sensor's limitation.

How it has been handled

Project Blue Book initially closed the case as a misidentification of an airliner. That conclusion was rejected by subsequent reviewers, including the Condon Committee's investigator Dr James McDonald, who interviewed the crew, reconstructed the timeline, and published an analysis arguing that no airliner could have produced the observed sensor signatures across the observed trajectory. McDonald's analysis is the document most-cited by contemporary researchers when the case is referenced. Blue Book later revised the case's classification but did not produce an alternative conventional explanation that withstood examination.

The RB-47 case remains in the small set of historical American UAP cases — together with the Washington National incidents of 1952 and a handful of Project Blue Book "unknowns" — that researchers across both skeptical and openness-favouring orientations treat as evidentially serious. It is one of the cases most frequently raised in contemporary congressional testimony on UAP. For comparison with other Cold-War-era multi-sensor cases, see the SkyLens UAP files page.

Editorial note: Independent SkyLens analysis of a publicly documented historical UAP case from the United States. The case index linking related releases and primary sources is on the SkyLens UAP files page.