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AN/TPX-42A(V)13 Interrogator Set

The Interrogator Set AN/TPX-42A, commonly referred to as Amphibious Air Traffic Control Direct Altitude and Identification (AATC DAIR), is an automatic beacon and radar tracking system that provides safe, terminal air space control of aircraft operations in an amphibious assault environment. Although the IFF system is the primary means of identifying aircraft, the AN/TPX-42A also processes a radar data source for the detection and tracking of targets. The AN/TPX-42A automatically tracks Mode 1, 2, 3/A, and C equipped aircraft and provides the air traffic controllers with an alphanumeric display of aircraft identity, altitude, and other amplifying data which is superimposed over the appropriate radar video on the plan position indicator consoles. This system is also capable of processing and displaying flight plans, geographic reference points, and map lines for easy association with mission operations. The AN/TPX-42A utilizes the AN/SPN-43C radar as the primary source of radar data, and the AN/SPS-49A radar as the secondary source of radar data.

The computer software program of the AN/TPX-42A system provides a real-time Direct Altitude and Identity Readout (DAIR) system for automated data gathering, tracking, storage, display and dissemination of information to assist Helicopter Direction Center (HDC) and Tactical Air Coordination Center (TACC) personnel in their duties.

The AN/TPX-42A system uses the IFF video via the AN/SPN-43C antenna group (primary) and the AN/SPS-49A antenna to provide IFF target reports to the video signal processor. These target reports are processed and reformatted for display on the 22-inch CRT of eight ADS consoles. The ADS consoles are used for control of rotor and fixed wing aircraft during launch/recovery and amphibious assault operations. The ADS consoles are designated as Approach A, Approach B, Departure/Assaults, Marshall/Supervisor, Assault Aircraft Coordinator, Air Warfare Coordinator, Air Traffic Controller, and Force Helicopter Coordinator. Selected targets are console designated when they can be associated with prestored aircraft parameters in the program.

The man/machine interface with the AN/TPX-42A program is provided by the ADS consoles. In addition to the above mentioned 22-inch CRT, each console has a keyboard entry device for formulating inputs to the program and an indicator controller for selecting inputs to the console. The AN/TPX-42A program provides alphanumeric data on the CRT for all IFF or radar targets within range and amplified information for targets under control of the console operator. Air plan lists and system data are also displayed on predetermined consoles.

The computer software program of the AN/TPX-42A system interfaces with CDS to provide an avenue for the exchange of information to enhance the independent functions of the operators in CIC, TACC, and the HDC and to provide for the interdependent functions required by Naval Air Training and Operating Procedures Standardization (NATOPS).

Navigational data is supplied periodically so the AN/TPX-42A can maintain ownship relationship to geographically fixed points and can accurately display final approach bearings. To allow the AN/TPX-42A to display restricted flight areas, danger zones and transit corridors consistent with those entered in the CDS computer by operators in CIC, the CDS program supplies information on geographically fixed lines in its database to the AN/TPX-42A upon request.

The AN/TPX-42A periodically transfers IFF target information and Mode 4 interrogation requests to CDS so that CIC will have the benefit of the medium range automatic tracking of IFF response targets, and AN/TPX-42 can display Mode 4 interrogation responses. Request for Handover, Handover and Handover Accept messages are exchanged, indicating that control of aircraft is being transferred from CIC or TACC to the HDC and vice versa. Handover Reject or Cancel may be exchanged to prevent transfer of control. The AN/TPX-42A and CDS can also inform each other of downed aircraft positions to assist in search and rescue operations.

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Maintained by Robert Sherman
Originally created by John Pike
Updated Wednesday, June 30, 1999 4:31:35 AM