Value chain · CLM-1363
In plain terms
With an aircraft's own radar aimed at the cockpit, the metal front of the fuselage kept the cockpit below what the meter could detect.
The claim as recorded
A 1974 EPA measurement article reports that no level above 0.2 mW/cm2 (2 W/m2), the meter's detection floor, was found in the cockpits of a Convair 600 and a Sabre Liner with their nose radars transmitting, even with the Convair's antenna pointed straight at the cockpit and turned to seek reflections from wings and propellers. It attributes the Convair result to the flat metal bulkhead at the front of the fuselage between the antenna and the cockpit. A probe held at arm's length outside the pilot's window read slightly above 0.2 mW/cm2. The Convair radome attenuated about 5.5 dB (a power factor of 0.28), and 10 mW/cm2 occurred 8 to 18 feet from the antennas on the main beam.
Evidence behind this: T3, a government agency periodical article reporting measurements, refereeing not confirmed (coord tier ruling 2026-10-03); it permits "the article reports Y".
Scope and limits
The emitter is the aircraft's own X- or C-band weather radar a few metres away behind a bulkhead, not an external 2.45 or 5.8 GHz beam over the airframe. The cockpit result is a detection-floor bound, so no shielding figure in dB can be derived. Two aircraft types, on the ground. 0.28 = 10^(-0.55) checks (my arithmetic). 8-18 ft = 2.4-5.5 m.
What it assumes
No assumptions are recorded against this claim.
Where it comes from
PDF p.14 / printed 174: front of the fuselage a flat metal plate that shields the cockpit; nose-cone attenuation test (paraphrase). PDF p.16 / printed 176: radome 5.5 dB or 0.28; cockpit survey of both aircraft below the 0.2 mW/cm2 minimum detection; worst-case antenna position; reading just over 0.2 outside the window (paraphrase). PDF p.17 / printed 177: conclusions d, e and f (paraphrase). PDF p.1 / printed 161: abstract (paraphrase).
Basis: mW/cm2 by Narda survey meter (detection floor 0.2 mW/cm2); radome loss in dB; aircraft on the ground
Related records
- Answers question
- QST-024 not published in this release
Cite this
energyaperture.com/c/clm-1363
CLM-1363, Energy Aperture, as of 1974-04.