SES: Raytheon - Generic Airborne Successor IFF Display and Control Devices Type 2/3

Under one of the largest programmes awarded to SES, Raytheon Systems Ltd have placed a subcontract with SES for the design development and manufacture of 4 variants of a Control and Display Unit - airborne and naval - to support the UK Successor IFF upgrade programme. Within this programme SES are developing and manufacturing two aerospace variants of a control and display unit, which have been given the Raytheon product identification IFF 4870 TCDU.

The IFF 4870 TCDU is an IFF Transponder Control and Display Unit which, in conjunction with an IFF 4810 Transponder unit and suitable antenna, system can be employed on aircraft, to provide, in response to an interrogation, a reply identifying platform friendly status.

The IFF 4870 TCDU provides all the controls and displays necessary for Transponder operation on all IFF Mk XII modes, Mode S and TCAS. The unit provides further expansion capability to the requirements of Mode 5 when this is available.

The IFF 4870 TCDU provides bi-directional serial data interfaces and discrete signals to the Transponder for selection of Transponder control functions and readback of Transponder status information.

Key functional requirements of the TCDU are:

• Provision of Transponder controls and displays for Transponder operation on Modes 1,2,3/A,4,5,C and S
• Transponder controls for the selection of TCAS Traffic Advisory (TA) and TCAS Traffic Advisory/Resolution Advisory (TA/RA), TCAS Range and TCAS Above/Normal/Below
• Provide controls for selection of Automatic Code Changing on Modes 1 3/A
• Provide control for either one or two Transponders
• NVG compatible display and panel lighting
• Comprehensive BIT facilities to enable fault finding to module level
• Provide the facility for the input of Flight Identity and a Mission Mode S Address

The design adopted by SES draws upon our experience of cockpit mounted display controllers adopting a dual processor architecture in which one processor is dedicated to the maintenance of the link with the IFF equipment, while the other processor manages all interaction with the pilot through displays and switches.

Given the importance of the IFF function to mission success and to the safety of the pilot, the SIFF TCDU is classified as a safety related item and all system, hardware and software design has had to take due account of the requirements of DefStan 00-55 and DefStan 00-56. The SES developed SIFF controllers will be deployed in a wide variety of operational aircraft including VC10, Nimrod, Gazelle, Puma, Lynx, Islander and Tristar.