Chapter 7 - Directional Gyroscope Flashcards
What is the principle of operation of a DGI?
Uses the gyro’s rigidity to stabilise an
azimuth scale (horizontal). Better long-term stability than a direct reading magnetic compass.
What is the spin axis of a DGI?
Perpendicular to the normal or vertical axis of the aircraft
What is an Electronic Horizontal Situation Indicator?
Is a DI, with a CDI (Course Deviation Indicator)
Why will the gyro not topple during synchronisation?
The arm comes up and grabs the gyro, preventing the gimbal from moving.
What is the cause of real drift?
The cause of real drift is Gimballing Error.
Anytime the gimbals are not at 90 Deg to each other (turning) then there will be gimballing error
Gyro moves to the right, what does it look like? NH
You’ve moved to the left
What is the equation for Earth Rate?
ER = 15 Deg x sin(latitude) degrees/hour
E.g at 47 Deg North, Earth Rate is 15 x sin(47) = 11 deg/hr
answer in deg/per hour
What is transport wander?
gyro will maintain its original with the north direction as was initially aligned with north, will appear to wander if it travels in an east-west direction. Due to convergence of the meridians.
