The flight interphone and audio system provides listening facilities for any
combination os audio signals from the receivers and side tones from the
transmitters without interaction between the audio panels. It also provides
inter-communication between two or more crew members. In addition, a jack
outlet in the external power receptacle permits flight interphone communication
with ground personnel.
The system employs three audio panels, each including an integral amplifier. The
audio panels are used to control all functions of the flight interphone and audio
A jackbox with outlets for headset, boomset, hand microphone and oxygen mask
microphone is connected to each audio panel on flight deck. The pilots boom oxygen
mask microphones are controlled by the corresponding control wheel microphone
Each crew member, including the observer, is provided with a hand microphone,
controlled by an integral press-to-talk button. On the R/P station, an additional
hand microphone is installed on the right side of the pedestal. There is one
loudspeaker above each pilot station. They are used to monitor the interphone
and audio system without having to use the headset.
- 1. MICROPHONE SELECTOR BUTTONS.
- When depressed and lighted, the microphones associated with the connected
audio panel are connected to the selected communication system.
INT communication pilot/mechanic.
HF-1/2 not in use.
- 2. AUDIO CONTROLS.
- Adjusts the output of any combination of receivers, interphone and
passenger address systems.
- 3. Volume controls to different navaids.
ADF RED/GREEN only ON/OFF.
FILT, used to reject the call sign (1020 cps)from a broadcast with simultaneous call
sign transmission (FILT position).
PA Passenger address.
MKR Marker beacon.