A spring-loaded, three-position microphone trigger switch, marked “ICS” and “RADIO”, is located on the pilot’s and co-pilot’s cyclic stick (Figure 1-6-2). It connects their respective microphones to the ICS transmission circuit when held in the ICS position, or to the radio transmission circuit when held in the RADIO position.

The TACCO and SENSO/sonar operator each have a foot-operated three-position microphone switch, (Figure 1-10-2). Depressing the upper portion (toe) of the foot switch connects that microphone to the ICS transmission circuit, while depressing the lower portion (heel) connects the microphone to the radio transmission circuit. They also each have a spring-loaded microphone toggle switch at their positions (Figure 1-10-5). It is marked “TRANSMIT” and connects that microphone to the radio transmission circuit.

The hoist operator has a microphone switch on the portable hoist control for ICS transmission. The switch is operated by pushing the thumb switch to the right.