is static in time.   

is static in time with respect to the geographical poles.   

is the same as the geographical poles.   

periodically wander (as much as 15 km every year).   

one degree of freedom, and an automatic erection system attempts to align its rotor spin axis to the local

one degree of freedom, and an automatic erection system attempts to align its rotor spin axis with the

 two degrees of freedom, and an automatic erection system attempts to align its rotor spin axis to the local

two degrees of freedom, and an automatic erection system attempts to align its rotor spin axis with the

that shows pitch, roll, and yaw angles

with a Flight Director Indicator.

combined with a directional gyro.

whose scale shows attitude commands.

Transport wander.

Earth rotation error.

Real wander.

Apparent wander.

The higher of VNE and VMO.

The lower of VNE and VMO.

VNE

VMO

a directional gyro indicator.

a strap down inertial system.

a gyromagnetic indicator.

an air driven artificial horizon.

forces are along the aircraft pitch axis.

forces are along the normal axis.

forces are along the lateral axis.

forces are through the gravitational center.

The gyroscopic unit.

The magnetic compass.

The flux detection unit.

The deviation card.

6°E

4°E

4°W

6°W

electronically sense the horizontal component of the Earth's magnetic field.

nothing.

electronically sense the vertical component of the Earth's magnetic field.

sense the horizontal and vertical components of the Earth's magnetic field.