Chapter 18A - Inertial Navigation Flashcards
INS measures?
Track and Groundspeed
Is INS self contained?
Yes
Any inertial system must be given a _____ on which it will base all its calculations
- starting reference point
INS requires no external information except? and from what?
TAS from the ADC
INS follows what?
Great Circles
Commonly the alignment of accelerometers is _____ or Longitudinal axis and _____ or Lateral axis.
- North/South
- East/West
If acceleration is measured, integration with respect to time will provide? Is this first or second stage integration?
Velocity
First stage integration
A integration with respect to time will give _____, or distance travelled in a particular direction. Is this first or second stage integration?
- displacement,
Second stage integration
What two things do you need to initially put into an INS?
Position, Speed
What navigation capabilities does an INS give you?
Position (latitude & longitude)
Heading/drift
Track/groundspeed
Waypoint navigation
Planned track
Distance and time to go
Cross track error
Track angle error
Can also provide:
Roll and Pitch
Accelerometer uses a?
Repulsive magnet - bigger the displacement bigger the repulsive force
INS Panels – Mode Select Unit (MSU), STBY is?
System powers up, gyros are brought to speed and temperature. The aircraft can be moved.
In EASA you have to be ___ to do an alignment?
Stationary
INS Panels – Mode Select Unit (MSU), ALIGN is?
The system levels and aligns the platform. Once complete, the READY NAV light goes on. The aircraft must be stationary during the alignment process.
in an INS alignment the accelerometers do?
Levelling
In INS alignment, what is caging?
Gimbals are driven to 900 to one another, voltage applied to heat oil, gyros brought up to speed.
How long does alignment take on an INS?
17 Minutes
How long does caging take on an INS alignment?
3 Minutes
How long does levelling take on an INS alignment?
3 Minutes
How long does gyrocompassing take on INS alignment?
11 minutes
An INS does not calculate?
Longitude
With longitude:
Two repeated crew inputs different from the stored value?
The system accepts the new value.
With latitude:
Two repeated crew inputs different from the calculated value?
The system does not complete alignment.
An INS does not compute its?
Longitude - you have to input it
