TM 1-1510-218-10
3A-17
3A-14. RADIO MAGNETIC INDICATORS (RMI).
a. Description. The Radio Magnetic Indicators
(RMI) are navigational aids that provide aircraft
magnetic or directional gyro heading and VOR or ADF
bearing information. Refer to Figure 3A -7. Two RMI
indicators are installed. The pilot’s RMI is identical in
operation with the copilot’s except that the copilot’s
COMPASS # 1 / # 2 switch is used to select
information for display on the compass card of the
indicator. The pilot's RMI is protected by a 1-ampere
RMI #1 circuit breaker and the copilot's RMI is
protected by the 1-ampere RMI #2 circuit breaker.
Both circuit breakers are located on the overhead
circuit breaker panel, Figure 2-16, Sheets 1 and 2.
b. Associated Controls and Functions. Refer
to Figure 2-17, Sheet 1.
(1) Pilot’s COMPASS Switch.
Selects
desired source for magnetic heading information for
display on pilot's RMI compass card.
(a) # 1. Selects compass system No. 1
for display.
(b) # 2. Selects compass system No. 2
for display.
(2) Copilot’s COMPASS Switch. Selects
desired source for magnetic heading information for
display on copilot’s RMI compass card.
(a) # 1. Selects compass system No. 1
for display.
(b) # 2. Selects compass system No. 2
for display.
c. Controls and Functions. Refer to Figure
3A-7.
(1) Double Needle Pointer. Indicates bearing
selected by double needle switch.
(2) Compass
Card.
Indicates
aircraft
heading at top of dial.
(3) Heading Index. Reference point for
aircraft heading.
(4) Warning Flag. Indicates loss of heading
signal or that bearing information is unreliable.
1. Double Needle Pointer
2. Compass Card
3. Heading Index
4. Warning Flag
5. Double Needle Switch
6. Single Needle Pointer
7. Single Needle Switch
Figure 3A-7. Radio Magnetic Indicator (RMI)
(5) Double Needle Switch. Selects desired
signal to be displayed on the No. 2 double needle
pointer.
(a) ADF Position. Selects ADF No. 2
bearing information.
(b) VOR Position. Selects VOR No. 2
bearing information.
(6) Single Needle Pointer. Indicates bearing
selected by the No. 1 single needle switch.
(a) ADF Position. Selects ADF No. 1
bearing information.
(b) VOR/GPS Position. Selects VOR No.
1 or GPS bearing information.
(7) Single Needle Switch. Selects desired
signal to be displayed on the No. 1 signal needle
pointer.
