Magnetic Compass Flashcards
(11 cards)
What components make up the float assembly in a magnetic compass?
The float assembly consists of magnetized needles, a compass card, and a float mounted on a pedestal.
What function does the fluid inside the magnetic compass serve?
It reduces oscillations, lubricates the pivot, and provides buoyancy to minimize weight on the pivot.
What is magnetic variation?
The angular difference between true north and magnetic north due to the Earth’s magnetic field misalignment with geographic poles.
What is compass deviation?
The disturbance in compass readings caused by local magnetic fields from aircraft engines, metals, and electronic equipment.
How is compass deviation corrected?
By periodically swinging the compass and recording corrections on a compass correction card.
What causes magnetic dip error?
The tendency of a compass needle to point downward as well as toward the magnetic pole, increasing closer to the poles.
What is acceleration/deceleration error in a magnetic compass?
Due to the dip of the Earth’s magnetic field, the compass incorrectly indicates a turn toward north when accelerating and toward south when decelerating.
What mnemonic is used for acceleration/deceleration errors?
ANDS: Accelerate North, Decelerate South.
What is the most pronounced compass dip error?
Northerly and southerly turning error, where the compass lags or leads depending on the heading.
What mnemonic helps remember turning errors in the Northern Hemisphere?
UNOS: Undershoot North, Overshoot South.
What causes compass card oscillation error?
Erratic movement of the compass card due to turbulence or rough control technique.
