The TACCO and SENSO/sonar operator ICS isolation selector panel (Figure 1-10-4) consists of a switch marked PILOTS ICS/SONAR ICS. The switch provides isolated ICS for the TACCO and SENSO/sonar operator, independent of interphone communications between pilot and co-pilot. When the switch is selected to SONAR ICS, the TACCO and SENSO/sonar operator can only communicate to each other. When selected to PILOT ICS, the TACCO and SENSO/sonar operator can communicate with all ICS stations.

When the pilot or co-pilot wishes to communicate with the TACCO or SENSO/sonar operator while the latter is on sonar isolate, the switch marked “SONAR CALL” on the collective stick (Figure 1-6-1) shall be depressed or the switch marked “SONAR INTERCOM” on the overhead switch panel shall be placed to ON and shall be used in conjunction with the normal ICS microphone switches. At all operator’s ICS control panels is a switch marked “COLD”, “HOT” and “CALL”. When held in CALL position by any operator, all stations are in communication.