HI

This provides suction to drive the gyro of the heading indicator

vacuum pump

It indicates the current heading of the aircraft and degrees in relation to a directional reference

Heading Indicator

 What is the directional reference used in aviation

Magnetic North Pole

the pilot uses this instrument since it does have the ability to align itself with magnetic north then the pilot must align the heading indicator using this instrument

magnetic compass

Why can’t the magnetic compass be used instead of HI

suffers from significant errors during turns accelerations Maneuvers or turbulence

its design causes the compass card to move in the opposite direction to the turn 

these are reference angles relative to the aircraft's current heading;  these angles are not measured in relation to magnetic north but in relation to the current heading

relative heading markings

prevent free gyro rotation at excessive pitch or bank angles, causing the instrument to become inoperative until reset

mechanical stops

on electric driven heading indicators the pitch and Bank limits

around 85°

on air driven heading indicators the limits are

around 55°

the earths rotation causes the gyro to deviate over time, leading to incorrect heading indicators

apparent wander

where is the apparent wander is maximum and minimum?

 maximum at the poles and minimum at the equator

magnitude of the apparent wander depends on the

latitude

imperfections in the instruments mechanism cause the gyro to drift

real wander

Real Wander degrees per hr

1° per hour

During flight, adjustment should only be made when

flying straight and level with a constant speed

 it consists of a heading indicator that instead of incorporating a free gyro. it has a slave gyro it uses a system of remote magnetometers to determine the direction of magnetic north and this way it automatically and constantly realigns the instrument

 gyromagnetic compass or remote indicating Compass

What gyroscopic effects does the heading indicator uses

rigidity in space

this continuously senses the earths magnetic field, and a servomechanism constantly corrects the HI

Flux Gate

Every when should HI be manually aligned

every 10 to 15 mins

This combine navigation and heading instruments into one

Horizontal situational indicators

How many degrees should the HI not precess in 15 mins

3 degrees

It is a required instrument for IF operations?

Directional Information

This reduce pilot workload by eliminating the need for manual realignment?

slaved gyros

It constantly correct the heading indicator?

servomechanism

What happens when a concentration of lines of magnetic force are amplified?

it becomes a signal relayed to the HI

What is connected electrically to the HSI?

magnetic slaving transmitter

Acronym for Day and Night IFR

GRABCARD

Instrument errors

Tumble
Precession

Direction measurement in degrees?

Azimuth

In what degrees per hour does the earth rotate?

15 deg / hour

What happens when a knob is pulled out?

the gyro remains rigid and aircraft is free to turn around

When a knob is pushed on the front of the instrument below the dial, what is engaged?

Gimbal

It’s spun either electrically, or using air from a vacuum pump (sometimes a pressure pump in high-altitude aircraft) driven from the aircrafts engine?

Gyroscope