Inertial Reference System

Question 1

Strap-down IRS systems have 3 whats and 3 whats?

Answer 1

3 ring laser gyros and 3 accelerometers.

Question 2

During alignments of the IRS, accelerometers and computers determine the orientation of the blank relative to the aircraft.

Answer 2

Vertical.

Question 3

What is the RLG within the IRS and how does it work?

Answer 3

Ring laser gyro is two laser beams directed around a triangular path. Frequency shift due to distance change works out rotation.

Question 4

How long does it take for a ring laser gyro within an IRS to begin working?

Answer 4

Instantaneously.

Question 5

How long does it take for a mechanical rate gyro within an IRS to begin working and why?

Answer 5

A few minutes. Fluid must be heated up before alignment can begin.

Question 6

Which is modern the IRS or the INS?

Answer 6

IRS

Question 7

What is an ADIRU?

Answer 7

Combined ADC + IRU
AIR DATA COMPUTER + Inertial data

Question 8

What does a dither motor do in an IRS?

Answer 8

Prevent Laser lock