ICS - Intercommunications System

The ICS provides normal, backup, or emergency communications between crewmembers. It also combines and amplifies audio signals received from other electronic receiving equipment (ECM, Sidewinder tone, IFF/SIF, radar altimeter, and voice radios, etc.). Identical ICS control panels are on the pilot and RIO left side consoles. The ICS consists of four amplifiers, two at each cockpit station, which permit duplex operation during normal operation. If one amplifier fails, it may be bypassed by selecting either the B/U (backup) or EMER (emergency) position on the ICS control panel. This permits continued ICS operation.

💡 If two amplifiers fail at the same station, intercommunication is impossible.

💡 By selecting EMER on the respective ICS control panel and using the other crewmember’s amplifier, you can listen in on audio normally only available at that station (like SW-tone or ALQ-126 PRF) but you lose the ability to control the volume of the audio you listen to.

The external interphone connection is in the nose-wheel well. When the pilot ICS switch is set to HOT MIC, ground personnel can communicate with the cockpit stations. In DCS, this works through selecting the ground crew communication menu in the DCS radio communication menu when activating ICS PTT.

The Pilot Radio ICS button allows for various intercommunication and radio operation modes. When set to ICS, it permits intercommunication when COLD MIC is selected on the function selector, overriding UHF/VHF communications. In the BOTH position, it keys both radios for operation, although this function is not active in DCS. The UHF 1 position keys the ARC-159 radio, and the UHF 2 position keys the ARC-182 radio.

The VOL control is used to control the intercommunication audio level at the specific cockpit station where it is adjusted. The audio levels at other stations remain unaffected by changes to this control.

The Amplifier selector has three positions: B/U (Backup), NORM (Normal), and EMER (Emergency). The B/U position is used to bypass a faulty amplifier, utilizing a backup output amplifier at the current station. The NORM position is for normal operation when all amplifiers are functioning correctly. The EMER position bypasses a faulty amplifier and uses the input amplifier of the other station, though HOT MIC is not available in this mode. It is important to note that with the front cockpit amplifier selector switch in the EMER position, engine stall/overtemperature and Sidewinder tones will not be available to the pilot.

The Function selector has multiple settings to manage radio and intercommunication audio. The RADIO OVERRIDE setting attenuates noncritical radio audio to prioritize intercommunication when urgent. The HOT MIC setting allows for intercommunication without keying, while the COLD MIC setting requires the pilot to actuate the ICS keying switch on the inboard throttle or the RIO to actuate the keying switch on the left footrest for intercommunication.

The RIO’s ICS button located on the left footrest permits intercommunication if COLD MIC is selected on the function selector control, overriding UHF communication. The RIO’s MIC button, found on the right footrest, allows for the transmission of UHF 1 or UHF 2 radios as selected on the communications/TACAN command panel. Note the BOTH function is not active in DCS.

💡 The two RIO foot-pedals have axis bindings in DCS to allow sim rudder pedals to trigger these functions.