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Gyro Compassing Circuit Board

Technical Information

Catalogue No: C0896
Category: Gyro
Object Type: Module/Sub-Assembly/Component
Object Name: Gyro Compassing Circuit Board
Part No: DL 7704-00007
Serial No: 5047
Manufacturer: Elliott Bros (London) Ltd
Division: Inertial Navigation [IND]
Platform(s): Jaguar
Year of Manufacture: circa 1968
Dimensions: Width (mm): 107
Height (mm): 157
Depth (mm): 19
Weight (g): 256
Location: Rack RAA03 [Main Store]
Inscription(s):

Gyro Compassing
Ref No 6JA/6191051
Ser. No. 5047
DL 7709-00007
Issue 4
[Mod State] 0

Notes:

This is an Gyro Compassing Circuit Board from the E3R-D1 Inertial Platform forming part of the Jaguar NAVWASS. The Circuit Board reference is not currently known.

In 1967 Elliotts had been awarded a major contract for the design, development and integration of a Navigation and Weapon Aiming Sub-System (NAVWASS) for the RAF's new Jaguar aircraft.

The Jaguar was designed as a close air support aircraft for supporting ground troops in daylight. The NAVWASS enabled the pilot to navigate and fly at low level and high speed to acquire and accurately attack targets. Trials of the prototype Jaguar system were carried out using a Varsity aircraft at West Malling airfield in Kent

 

The Jaguar NAV/WASS  sub-system comprises four principal groups of equipment. The sensors, which measure what the aircraft is doing and feed these measurements into the computer; the computer sub-system which processes this measured information into a form which can be used by the pilot; the cockpit controls which control the system's mode of operation and lastly, the cockpit displays which show to the pilot the computer's outputs of converted measurement information and also information, such as target or waypoint position, which is being input into the computer. The system included an E3R inertial platform, Digital Computer, a HUD, Projected Map Display, Horizontal Situation Indicator and various cockpit control panels.

In an attempt to make use of the experience gained in the 1960’s designing the inertial navigator for the ‘Blue Steel' air-to-surface missile the Company embarked on the development of a general-purpose instru­ment for aircraft navigation, and an experimental stable platform, E5 was built. This project was not completed, as it was realised that the platform was likely to be too bulky for many applications, and improvements in technique appeared to offer scope for a reduction in size. A project to develop a new platform was commenced in the Company Research Laboratory, FARL, where fortuitously the majority of the small team of engineers had been in the Inertial Navigation Division including the Chief Engineer 'Dick' Collinson and the Chief Designer 'Staff' Ellis. FARL produced the E3 stable platform, using a novel gimbal system which permitted a very compact construction.  A trial of this platform was madse in early 1963 at Cranfield with the E3 Platform mounted under the canopy of a Gloster Javaelin. This design entered production for the Hawker Siddeley Aviation HS801 'Nimrod' maritime strike and reconnaissance aircraft and between 1964 and 1970 over 100 platforms were delivered.

However  a further development of the E-3 platform, the E-3R which permitted a wider range of manoeuvre, was specified for the BAC/Breguet  'Jaguar' fighter, and entered service in 1970 rapidly becoming an industry standard. The E3-R had a fourth gimbal and incorporated continuous rotation of the two vertical gyros and horizontal accelerometers to achieve 'rotaional averaging' giving greatly increased accuracy.

The Jaguar Navigation and Weapon Aiming Sub-System NAVWASS  comprised the MCS920M central digital computer, E3R inertial platform, projected map display and horizontal situation indicator together with the necessary power supply, electronic, interface and control units.

The main unit of the inertial subsystem is the platform assembly which contains a stabilized inertial platform or stable element, the basic attitude reference for the system. The chief function of the platform is to provide a means of accurately locating the gyros and accelerometers and to maintain their orientation fixed to the local vertical and to true north regardless of anv aircraft motion. The electronic control amplifier contains the electronic amplifiers and special excitation sources required for alignment and operation of the inertial platform. These include the gimbal servo amplifiers and the gyro spin motor power supply.

 

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