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Synchro Interface Module (SIM)

Technical Information

Catalogue No: C0638
Category: Air Data
Object Type: Module/Sub-Assembly/Component
Object Name: Synchro Interface Module (SIM)
Part No: 60220-007-02
Serial No: 06057
Manufacturer: GEC Avionics
Division: Instrument Systems [ISD]
Year of Manufacture: circa 1988
Dimensions: Width (mm): 180
Height (mm): 165
Depth (mm): 13
Weight (g): 409
Location: Rack RAA03 [Main Store]

Ser No 06057


Totally isolated analog signals, which duplicate existing interfaces, are generated on the Synchro Interface (SIM), Synchro Transformer (STM), and Potentiometer Interface (PIM) Modules. This is a Synchro Interface Module (SIM) core module from the (SCADC) and was manufactured by Instrument Systems Division (ISD) Printed Circuit Board shop.

In 1981 Instrument Systems Division began the design of a new generation of Air Data Computers designed for the combined USAF and USN Standard Central Air Data Computer (SCADC) programme. The system was designed to fulfil the retrofit requirements of 38 different aircraft types and to do so with only four configurations. The aircraft types include the following:-


A-4M and TA-4J Skyhawk, A-6E/F, KA-6D and EA-6A Intruder, EA-6B Prowler, TC-4C Gulfstream, A-7D/E/K and TA-7C Corsair II, C-2A Greyhound, E-2C Hawkeye, KC-135 Stratotanker, C-5A/B Galaxy, C-141A/B Starlifter, F-111A/E/D/F, FB-111A, EF-111A, F-4C/D/E/G/J/N/S, and RF-4B/C Phantom and the S-3A/B and US-3A Viking. In 1992 an order for a further 290 units was received, being the eighth option, bringing the total procured to 5552 units. 387 units of the SCADC system were at this time being supplied for the F-14 Tomcat.


The high commonality was achieved with a unique software re-configurable design. Output parameters, ranges and scalings are selected for each aircraft type by the software, which recognises the host from a code wired into the aircraft connector pins. The SCADC core hardware set provides over 80% of the hardware in every application and the remainder is addressed by one or two special-to-type modules. A multiplicity of analogue interfaces can be handled and the Mil-Std 1553 DataBus is also a feature. Production commenced in 1985 with first deliveries the following year and in 1989 these deliveries surpassed 4,000 units. In addition in 1988 ISD received the Queen’s Award for Technological Achievement for SCADC.


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