INSTRUMENTS Flashcards
The Earth is a huge ______, spinning in space, surrounded by a___________ made up of invisible lines of___.
magnet, magnetic field, flux
These lines leave the surface at the magnetic_______ and reenter at the magnetic ______.
North Pole, South Pole
Lines of magnetic flux have two important characteristics:
any magnet that is free to rotate aligns with them,
an electrical current is induced into any conductor that cuts across them
Most direction indicators installed in aircraft make use of one of these two characteristics
Lines of magnetic flux have two important characteristics
One of the oldest and simplest instruments for indicating direction
magnetic compass
basic instruments required by 14 CFR part 91 for both VFR and IFR flight
magnetic compass
The magnetic compass is the basic instrument required by ______ for both VFR and IFR flight.
14 CFR part 91
Is a piece of material, usually a metal-containing iron, which attracts and holds lines of magnetic flux
magnet
every magnet has two poles
north pole, south pole
When one magnet is placed in the field of another, the unlike poles _____each other and like poles _____
attract,repel
has two small magnets attached to a metal float sealed inside a bowl of clear compass fluid
An aircraft magnetic compass
compass fluid is made of
kerosene
wrapped around the float and viewed through a glass window
graduated scale, called a card
The magnetic compass, vertical line is called
lubber line
The card is marked with letters representing the _______, north, east, south, and west, and a number for each between these letters
cardinal directions, 30°
There are long and short graduation marks between the letters and numbers, with each long mark representing __ and each short mark representing ___.
10°, 5°
has a hardened steel pivot in its center that rides inside a special, spring-loaded, hard-glass jewel cup.
float and card assembly
allows the float freedom to rotate and tilt up to approximately 18° angle of bank
jewel-and-pivot type mounting
At __________, the compass indications are erratic and unpredictable
steeper bank angles
entirely full of compass fluid
compass fluid
To prevent damage or leakage when the fluid expands and contracts with temperature changes, the rear of the compass case is sealed with a ________, or with a metal bellows in some compasses.
flexible diaphragm
the pilot reads the direction on the scale_______ the lubber line
opposite
the pilot sees the compass card from its ________
backside
The reason for this apparent backward graduation is that the card remains ________, and the compass housing and the pilot turn around it, always viewing the card from its backside.
stationary
Magnetic fields caused by aircraft electronics and wiring can affect the ______ of the magnetic compass
accuracy
induced error is called
compass deviation
Compensator assemblies mounted on the compass allow aviation _______ to calibrate the compass by creating magnetic fields inside of the compass housing
maintenance technicians (AMTs
has two shafts whose ends have screwdriver slots accessible from the front of the compass
compensator assembly
MAGNETIC COMPASS ERRORS
Variation
deviation
northerly turning errors
southerly turning errors
acceleration error
oscillation error
Directions measured from the geographic poles are called
true directions
directions measured from the magnetic poles are called
magnetic directions
difference between true and magnetic directions is called
variation