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BendixKing FPI 3501B System FPD 500 User Manual

Page 43

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FPD 500 FLAT PANEL DISPLAY SYSTEM

4.2 HEADING FAILURE

Invalid heading is indicated by replacing the digital heading readout
with a red “HDG” flag. The compass card will continue to be dis-
played and will rotate in response to the heading signal received by
the EHSI. If the heading signal is not received by the EHSI, the com-
pass card will freeze at the last valid value for heading and the “HDG”
flag will be in view.

When the “HDG” flag is displayed, the positions of the selected head-
ing bug and selected course arrow should not be trusted. This is
because heading is used to generate the selected heading and
selected course signals received by the EHSI, and the validity of
heading at that location (outside the EHSI) is unknown.

Special Considerations

4-5

Rev. 0
Jan/97

A

Figure 4.2-1

Heading Failure Flag

N

M

R

I

DIM

TEST

BRT

0

33

30

27

24

21

15

12

9

6

3

18

GS

ILS 1

INS1

1234

INS2

1324

HDG