remote indicating compass

Question 1

the RIC

Answer 1

combination of DIC and DGI
takes long term accuracy of DI(S&L)
takes short term accuracy of the DGI(turns)

Question 2

RIC operation principles

Answer 2

uses tied gyro
gyros tendency to drift detected and driven back to correct orientation(known as slaving)
very similar to basic DI but RIC electrically powered
flux valve used to direct the orientation of the earths magnetic field relative to the aircraft
it detects orientation of gyro rotor relative to flux valve:
errors amplified and used to power torque motor which drives gyro back into sync

Question 3

RIC Flux valve

Answer 3

3 detector legs 120° apart
horns at end of legs, together form nearly complete circle
horns gather nearby magnetism and direct it through the 3 detector legs

Question 4

RIC flux valve mounting

Answer 4

mounted as far from flight deck as possible (wingtip, tailplane tip)
mounted pendulously from a hookes joint in a fluid filled chamber- allows it to hang in horizontal plane as attitude changes and fluid dampens the tendency to swing

stops horizontal rotation so flux valve rotates with the aircraft as it changes heading

Question 5

RIC flux valve errors

Answer 5

acceleration
turning
attitude
deviation

Question 6

RIC the stator

Answer 6

signals from flux valve are delivered to a stator in the DI
stator has 3 sets of winings 120° apart
each flux detector leg provides current to one stator winding
EM field mirrors that of the flux detector
creates field with same orientation as earths field- provides way of knowing where magnetic north is

Question 7

RIC the slaving circuit

Answer 7

used to stop the gyro drifting
detector coil mounted on drive shaft connected to outer gimbal and centre of stator
any output of detector coil sensed a precession motor drives it back to the null position
precession motor also drives gimbal back into position realigning the gyro

functions:
Amplification
phase comparison (stator & gyro)
rectification

Question 8

controls and annunciator

Answer 8

annunciator shows signal being passed to the torque motor
norm operation- needle gently moves R&L
in turn- needle moves one way to show operation of torque motor
2 settings:
free: operates as DGI
slaved: operates as RIC
can manually drive gyro into alignment by operating switch

Question 9

components of RIC

Answer 9

detector unit
heading indicator
signal amplifier
rapid synchronisation unit

all on troll and PP