PRIMUS
r
1000 Integrated Avionics System
A28--1146--112--00
C--27
PRIMUS
â
II Radio System
90
°
relative bearing position and removes ADF bearing needles from
electronic flight instrument displays until HF transmission ceases. This
avoids possible interference caused by bearing inaccuracy.
SINGLE ADF INSTALLATION
Single ADF installations operate the same as dual configurations
except that the ADF window annunciator does not identify a side
number. The main tuning page can be used to turn the ADF.
Cross--Side Operation
The RMU normally controls tuning of the radio system on its side of the
aircraft, but it can be switched into a mode called cross--side operation
to display and control the other radio system in the airplane.
If the pilot whose RMU normally tunes system No. 1, wants to tune the
copilot’s set of radios, the pilot pushes the 1/2 function key and replicate
the co--pilot’s No. 2 system (active frequencies, modes, and codes, but
not memory or preset frequencies) on the No. 1 RMU. Both RMU
displays are identical (except for memory and preset frequencies) but
the pilot’s RMU shows the function legends on the main tuning and
memory pages in magenta to indicate that cross--control is being
exercised. In addition to having access to the No. 2 system, the pilot still
has the NAV and COM memory frequencies in the No. 1 RMU available
to recall for use with the No. 2 system. Both pilots have this control
transfer function. The crew can coordinate tuning as well as have a
back--up mode in the event one RMU becomes inoperative.
NOTES:
1. Cross--side operation shifts between complete
systems. It is not possible to display/control on one
RMU some functions from the pilot’s side and some
from the copilot’s side at the same time.
2. The 1/2 function key does not affect the ATC window.
(Refer to note 3, below.)
3. Moving the cursor to the ATC window and pushing the
1/2 function key activates the opposite side
transponder.