« Previous Next »

GR-H4 Rate Gyro parts in a Display Panel

Technical Information

Catalogue No: C0614
Category: Gyro
Object Type: Module/Sub-Assembly/Component
Object Name: GR-H4 Rate Gyro parts in a Display Panel
Part No: None
Serial No: None
Manufacturer: GEC Avionics
Division: Guidance Systems [GSD]
Year of Manufacture: Unknown
Width (mm):
Height (mm):
Depth (mm):
Weight (g):
Location: Main Object Store

GR-H4 Rate Gyro
GEC Avionics
Guidance Systems Division
Main Assembly
End Shield Assembly & Flexicircuit
Inner Sleeve Assembly
Damper Assemby
Microsyn Assembly
Flex Lead Ring Assembly
Gimbal Assembly
Bellows Assembly
Microsyn Stator Assembly
Rotor Assembly
Torsion Wire Machining Assembly
Microsyn Rotor Stack Assembly
Rotor & Hysteresis Ring Assembly
Microsyn Stack Stator Assembly
Motor Stator Ring Assembly
GR-4H with Optional Sleeved Case


In March 1980 Marconi Avionics completed its 10,000th rate gyroscope, marking 15 years of manufacture which continued further. The GR-H4 rate-gyroscope was built under licence from Northrop, producer of the original version.

Applications of the Marconi Avionics-built gyroscope include the guidance system of Sky Flash, the RAF's most advanced air-to-air missile, and stabilisation of Harrier. Sky Flash can be launched from Phantoms and Tornado.

While building GR-H4s, Marconi Avionics introduced several improvements, independently of Northrop. These included replacement of the steel gyro-casing with one of Monel nickel alloy incorporation of a mu-metal screen to isolate the gyroscope motor's magnetic field; introduction of chemical etching (in place of lapping) to trim the torsion bar; adaption of semiautomatic test equipment and multiple jigging to simplify production. At the same time unit cost was reduced, in real terms, by a factor of almost three.

In 1980 GR-H4 production rate was roughly 100 units a month.

This exhibit is a perspex block containing a breakdown of parts forming the GR-H4 Gyro.

Click to enlarge
Related Items: