BendixKing IN-862A System RDR-2100 - Manual (Page 67)

Effective Date: 9/98 RDR 2100 Pilot's Guide: Rev 1
63
ADVISORY
CIRCULAR
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
Washington, D.C.
SUBJECT: Recommended radiation safety precautions for ground operation of air borne weather radar
Initiated by: AFO-512
PURPOSE. This circular sets forth recommended radiation safety precautions to be taken by personnel
when operating airborne weather radar on the ground.
CANCELLATION. AC 20-68A, dated April 11, 1975, is canceled.
RELATED READING MATERIAL.
a. Barnes and Taylor, Radiation Hazards and Protection (London: George Newnes Limited, 1963), p.
211.
b. U.S. Department of Health, Education and Welfare, Public Health Service, Consumer Protection and
Environmental Health Service, “Environmental health microwaves, ultraviolet radiation and radiation
from lasers and television receivers - An Annotated Bibliography”, FS 2.300: RH-35, Washington,
U.S. Government Printing Office, pp. 56-57.
c. Mumford, W.W., “Some technical aspects of microwave radiation hazards”, Proceedings of the IRE,
Washington, U.S. Government Printing Office, February 1961, pp. 427-447
BACKGROUND. Dangers from ground operation of airborne weather radar include the possibility of
human body damage and ignition of combustible materials by radiated energy. Low tolerance parts of
the body include the eyes and testes.
PRECAUTIONS. Management and supervisory personnel should establish procedure for advising per-
sonnel of dangers from operating airborne weather radars on the ground. Precautionary signs should
be displayed in affected areas to alert personnel of ground testing.
General.
(1) Airborne weather radar should be operated on the ground only by qualified personnel.
(2) Installed airborne radar should not be operated while the aircraft is in a hangar or other enclosure
unless the radar transmitter is not operating, or the energy is directed toward an absorption shield
which dissipates the radio frequency energy. Otherwise, radiation within the enclosure can be
reflected throughout the area.
Body Damage. To prevent possible human body damage, the following precautions should be taken.
(1) Personnel should never stand nearby and in front of radar antenna which is transmitting. When the
antenna is not scanning, the danger increases.
(2) A recommended safe distance from operating airborne weather radars should be established. A
safe distance can be determined by using the equations in Appendix 1 or the graphs of figures 1 and
2. This criterion is now accepted by many industrial organizations and is based on limiting exposure
of humans to an average power density not greater than 10 milliwatts per square centimeter.
(3) Personnel should be advised to avoid the end of an open wave guide unless the radar is turned off.
(4) Personnel should be advised to avoid looking into a wave guide, or into the open end of a coaxial
connector or line connector to a radar transmitter output, as severe eye damage may result.
(5) Personnel should be advised that when power radar transmitters are operated out of their protective
cases, X-rays may be emitted. Stray X-rays may emanate from the glass envelope type pulsar,
oscillator, clipper, or rectifier tubes, as well as magnetrons.
Appendix
RDR 2100 PG 3/12/07 3:45 PM Page 63