comms

Hydraulic Bay:
  - Ground crew can connect to hydraulic bay and ground power.
  - Doors not monitored are located below the empennage.
  - Access to the area includes getting into the "hellhole" for communication with the cockpit crew.
  - Communication is established through loudspeakers only.

Definition:
- Remote Control Audio Unit (RCAU) serves as an interface for audio management.
Operation of Audio System:
- Typically, audio files are located within the RCAU system to facilitate playback.
- Control via the audio control panel is required.
Control Panel Features:
- Attendant call feature is disabled.
- Functionality includes mechanisms to select between radio, internal communications, and mechanic calls.

Talk Functionality:
- Users must push a talk button to activate communication.
- Communication can occur via radio or internal mechanisms.
Mechanic Calls:
- There is a designated function to call a mechanic, though this may not be received positively due to loud ambient noise.

Oxygen Mask Usage:
  - Switch located in the oxygen mask box transfers transmission from the boom mic to the oxygen mask when in the release position.
  - Pulling out the mask opens doors, activating a hot mic environment.
  - A hand mic is also available, providing an alternative to the boom mic for communication.
Audio Panel Connection:
- The oxygen mask is pre-connected to the communication system, allowing quick setup.

VHF Communications:
- VHF comms discussed, in conjunction with intercom systems and the ground control interconnect station.
Internal Transmission Keys:
- Internal intercom allows for immediate communication, letting operators push buttons without using the yoke mic.
Communication Methods:
- Using the comm box directly provides options if the switch on the yoke fails.
- Some operators prefer reaching for the comm box instead of keying the mic on the yoke.

Yoke Functions:
- Allows for switching to VHF and controlling volume settings.
Control Mechanisms:
- VOR selections are available on the yoke.
- Public Address (PA) announcements are made from the back using a specific procedure.
Outdated Equipment:
- No longer using HF or Celcol systems, which were phased out long ago.
- Current systems utilize Collins control boxes instead of King avionics.

Internal Discussions:
- A brief overview of communication practices, including adjustments for loudspeaker volume.
Hot Mic Discussion:
- A "hot mic" indicates constant audio transmission without needing to push a button to talk.
- Usage: Operators can use headsets and loudspeakers in conjunction with the oxygen mask to facilitate communication during operations.

Audio Select Fault:
- If an error occurs, management of audio levels and notification systems becomes essential for operations.
Normal Functionality:
- The RCAU serves as a critical interface; if a fault occurs, it will activate CCaaS (Critical Communication As A Service).
- Understanding the failure process and alternate procedures is critical for maintaining communication integrity.

ELT Operations:
- Details on arming and testing the ELT as part of the aircraft's safety equipment.
Activation Protocol:
- To reset or arm the ELT, hold the reset button for two seconds to avoid accidental activation during emergencies.
- The impact of accidental activation is highlighted, emphasizing the seriousness of the ELT functionality.

General Communication Overview:
- Discussion around the current communication systems on board, including updates on Air Transport Regulations (ATR) in the US.
Changes in Air Transport Companies:
- Mention of changes in operations among various carriers such as Mountain and Silver Airways.
- Note that Silver Airways is no longer in business but there is ongoing service provided by another carrier in Alaska.
Break Schedule:
- Encouragement to take a break after intensive review of equipment and systems.