Chapter 18B - Inertial Reference Systems Flashcards
1
Q
RLG measures ?
A
Rotation around the sensitive axis
2
Q
What are some advantages of IRS over INS?
A
- Reduced alignment times, with little or no spin up time
- Improved accuracy – EASA 0.5 NM/hr
- Insensitive to gravitational forces
- Mechanically simple – better reliability
- Smaller and lighter
- Lower power consumption
- Longer MTBF – Mean Time Between Failures
3
Q
IRS is also known as a ?
A
Strap down system
4
Q
What’s the purpose of a dither motor?
A
Prevent laser lock
5
Q
For the alignment, the AC should be?
A
Stationary
6
Q
What is the overall alignment sequence in an IRS?
A
Overall alignment sequence…
- Automatic test of the battery
- Establish local vertical
- Establish True North
- Establish correct Latitude
The time for a normal alignment of a strap down inertial system is about 10 minutes.
7
Q
ATT gives you?
A
Attitude reference
8
Q
With an IRS, Two repeated long inputs different from the stored value?
A
The system accepts the new value.
9
Q
With an IRS, Two repeated latitude inputs different from the calculated value?
A
The system does not complete alignment.
