When storing a frequency, the second
actuation of the STO button must be done
channel number or the first actuation of the
STO button. If more than 5 seconds
elapse, the control will revert to the normal
modes of operation and the second store
command will be interpreted as the first
After a frequency has been stored in memory, it
will remain there until changed by using the STO
button. Memory is retained even when the unit is
turned off for an extended period of time.
d. Normal Operation.
(1) Function Selection. Position the power
and mode switch to ANT, ADF, or TONE (BFO).
preceding frequency select procedures, tune the ADF
until the desired frequency is indicated in the active
frequency display and verify the station identifier.
(a) ANT Function. Position the power
and mode switch to ANT. The RMI pointer will park
horizontally. Select ADF on the audio system and
adjust the volume.
(b) ADF Function. Position the power
and mode switch to ADF. The RMI pointer will
indicate relative bearing to the turned station.
When the ADF system is not receiving a
reliable signal, the RMI pointer will remain
parked in the ADF mode. The ADF may
momentarily park during station crossings
because of signal loss. If the bearing
pointer fails to respond as indicated or ID
is lost in ANT position, the ADF should be
considered unreliable and will not be used
for navigation or approaches.
(c) TONE Function. Position the power
and mode switch to TONE (BFO). A 1000-Hz tone will
identify keyed CW stations.
If the signal received is weak or of poor
quality, the bearing pointer rotation will be
1. Position the power and mode switch to
ADF and tune a nearby NDB, outer
marker, or broadcast station and press the
TEST button. The RMI pointer will rotate
90° from the previous valid indication.
2. Release the TEST button and verify that
the RMI pointer returns to that indication.
Select ANT on the ADF control panel.
Bearing pointer should point horizontally,
and a valid aural navaid identifier (ID)
3. Select ADF on the control panel. The
bearing pointer should return to the proper
3C-25. RADIO MAGNETIC INDICATOR.
Two identical Radio Magnetic Indicators (RMIs)
are installed, one on each side of the instrument panel.
Each RMI provides aircraft heading and radio bearing
information TO/FROM a VOR, TACAN, or ADF facility.
A selector switch on the RMI allows the operator to
select either ADF and #1 VOR or ADF and TACAN for
single needle display. The double needle always
points to the ADF or #2 VOR bearing as selected by
the double needle switch.
Aircraft RMI circuitry modified by Beech
Service Instruction No. C-12-0118, will
operate as follows: In addition to the
standard warning flag conditions, if a
TACAN circuitry 26 Vac electrical power
loss occurs and TACAN is selected, the
RMI single-needle pointer will drive to the
three o'clock PARK position.
Refer to Chapter 3D for detailed information.
a. Pilots Servoed Altimeter.
(1) General. The pilots altimeter provides a
servoed counter drum/pointer display of barometrically
corrected pressure altitude, derived from the air data
computer system. For proper operation, the 2-ampere
AIR DATA ENCODER circuit breaker located in the
avionics section of the right sidewall circuit breaker
panel must be set. The altimeter is 26 Vac powered,
and is protected by the 12-ampere PILOT ALTM
circuit breaker also located on the right wall panel.