PS Engineering Audio Panel and other Audio Switchology

Maj. Jeff Knutson

PS Engineering Audio Panel

Additional features for CAP operations More complicated than older units like KMA-24’s May be confusing if crew unfamiliar with

operation

Features

Can isolate pilot from rest of crew Useful in searches with heavy ATC or CAP communications

Can isolate front seat from back seat Can have pilot talking on different frequency than observer Can swap frequencies

Sometimes inadvertently!

Operation

Intercom volume Does not affect radio volume Push in to turn audio panel on/off

Marker Sensitivity Switch (3 position) High Low Test (lights)

Marker Beacon Lights (same as other units)

Intercom Modes

ISO Only pilot hears radios – Isolated from crew Observer and scanners have intercom Observer hears Com3

Intercom Modes

All Everybody hears everything

Intercom Modes

Crew (i.e. front seat) Pilot and Observer hear radios Front seat isolated from rear seat Rear seats have separate intercom and no radios

COM1

Activates audio for communication radio 1 Operation just like other audio panels Green light illuminates when activated

COM2

Activates audio for communication radio 2 Operation just like other audio panels Green light illuminates when activated

NAV1, NAV2, MKR, ADF, DME

Activates audio for selected radio Operation just like other audio panels Green light illuminates when activated

ICS (Intercom)

Opens intercom between pilot and observer during split modes

Green light illuminates when activated If not selected when split mode is selected pilot

will again be isolated!

COM3

Activates audio for CAP FM radio Green light illuminates when activated

SPR (Speaker)

Turns on cabin speaker Operation just like other audio panels Green light illuminates when activated

Transmitter Select Knob

Selects on which radio the pilot and observer will transmit

Transmitter Select Knob

Pilot: COM1 Observer: COM1

Transmitter Select Knob

Pilot: COM2 Observer: COM2

Transmitter Select Knob

Pilot: COM3 (CAP FM) Observer: COM3 (CAP FM)

Transmitter Select Knob - Split

Pilot: COM1 Observer: COM2

Don’t forget about ICS button!

Transmitter Select Knob - Split

Pilot: COM1 Observer: COM3

Transmitter Select Knob - Split

Pilot: COM2 Observer: COM3

Transmit Light

Illuminates when crewmember is transmitting on selected radio

Swap Light

Illuminates when swap mode is selected on control yoke Effects determined by transmitter select switch position Swap button is the same type and is right next to the mic button

Very easy hit hit accidentally Verify swap light mode when transmitting

Look out for this!

Swap Light Effects

Toggles between COM1 (no light) and COM2 (light)

Swap Light Effects

Toggles between COM2 (no light) and COM1 (light)

Swap Light Effects

No swap

Swap Light Effects

Pilot COM1, Observer COM2 (no light) Pilot COM2, Observer COM1 (light)

Again, in split mode, if ICS not selected pilot will be isolated

Swap Light Effects

Pilot COM1, Observer COM3 (no light) Pilot COM3, Observer COM1 (light)

Swap Light Effects

Pilot COM2, Observer COM3 (no light) Pilot COM3, Observer COM2 (light)

DF Audio Switch

Note there is no ELT DF button on audio panel

How does the crew hear ELT’s?

Remote panel switch

DF Audio Switch

Remote DF Audio toggle must be switched up to the ON position

Turning up the volume on the DF unit won’t help if the DF audio is switched OFF

Problems

Pilot can’t hear the Observer. What could cause this? Audio panel turned off Intercom in ISO mode Transmitter select switch in split mode and ICS button not

activated

ATC has been quiet, and now they don’t reply to my calls Check swap mode – might have hit it on the last transmission

and have been listening to the wrong frequency for the last 15 minutes

Problems

The scanner can’t hear the front seat crew or radios? Intercom in Crew mode Headset is unplugged

The crew can’t hear the ELT beacon Volume on DF unit is too low The remote DF audio switch is turned off