This course introduces the components, operation, controls and indications of the Communications Systems of the B737 aircraft. This outline includes the normal and abnormal operations of the following; a description of the audio panel, VHF/HF communication tuning and controls, the interphone systems for the flight and service systems, the passenger address system, and the Call/SELCAL operations, the cockpit voice recorder and the ACARS system. Courses are constantly monitored and updated when major changes in authority documentation is released.