TM 11-6660-266-13
Section IV - OPERATION UNDER UNUSUAL CONDlTlONS
SECTION
CONTENTS
Page
OPERATION IN UNUSUAL WEATHER ......................................................................... 2-52
EMERGENCY PROCEDURES ...................................................................................... 2-52
2-9. OPERATION IN UNUSUAL WEATHER.
2-9-1. Wind.
THE RDF ANTENNA MAY TIPOVER DURING HIGH WIND
CONDITIONS. THE RDF UNIT SHOULD NOT BE ERECTED IF
SUSTAINED WINDS EXCEED 45 KNOTS OR IF WIND GUSTS
EXCEED 65 KNOTS.
The AN/TMQ-38 should not be operated when sustained winds exceed 45 knots or wind gusts exceed 65 knots.
The major problem encountered during operation of the system during high wind conditions is the handling and
launching of the balloon/radiosonde. In addition, the RDF Unit SHOULD NOT be set-up or operated in sustained
winds exceeding 45 and/or wind gusts exceeding 65 knots.
2-9-2. Fog. Fog conditions should present no problems when operating in the NAVAID mode and no special
operating procedures are required. When operating In the RDF mode, fog may make it difficult to perform
azimuth and elevation alignment procedures. If heavy enough, the fog could prevent accurate alignment of the
RDF. Also, poor visibility could hinder visual tracking of the balloon/radiosonde and make it difficult to reacquire
tracking if lost during the initial stages of balloon/radiosonde launch.
2-9-3. Extreme Cold Temperature (Below 0 C). No special operating procedures are required for temperatures
below 0 C. The major problem encountered during operation of the system during extreme cold temperatures is
the handling and launching of the balloon/radiosonde.
2-10. EMERGENCY PROCEDURES.
The following special operating instructions should be followed during AC and DC primary power failures.
2-10-1. AC Power Failure.
When the system is powered by AC primary power and an interruption occurs, the MARWIN Processor, the
NAVAID Antenna Set, and the Printer will continue to operate for up to 2 minutes without the loss of data. If
power is lost for more than 2 minutes, then all flight data will be lost. Except for interruptions less than 20
milliseconds, all AC power interruptions will result in complete loss of operation of the DCT and RDF Unit. During
AC power failures, the system may be operated only in the NAVAID mode from a DC primary power source.
To operate the system in the NAVAID mode from DC primary power, proceed as follows:
If not, connect in
a. Check that power cable W3 is connected to DC power source and Power Supply Unit.
accordance with paragraph 2-4-4-f, step (4).
2-52
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