1. AVAT11001: Course Outline Aircraft and Terminology
Radio Communications
Structure, Propulsion, Fuel Systems
Electrical, Hydraulic Systems and Instruments
Air Law
Aerodynamics: Basics
Aerodynamics: Performance
Human Factors
Meteorology
Loading
Take-off and Landing Performance
Navigation

2. Stuff to read
Required Reading: BAK Chapter 4, pp

3. Sources of Electricity
Battery
Provides initial electrical power to start the engine
Provides back-up power in case of failures
Is recharged by the alternator during flight
Alternator
Driven by the engine
Generates current

4. Gauges and Instruments
Ammeter
Indicates electrical current level
Load-type Ammeter
Shows alternator output only
See Figure 4-68 page 107
Centre-Zero Ammeter
Shows flow to and from the battery
See Figure 4-69 page 108
Voltmeter
Indicates the system voltage
About 27.5 Volts indicated for a 28-Volt system
About Volts indicated for a 14-Volt system

5. Abnormal Electrical System Operations
Ammeter indicates
Too little current
Likely cause is alternator failure
The battery will be drained
Reduce electrical usage
Consider landing at nearest aerodrome
Too much current
Likely caused by faulty voltage regulator
May cause battery to overheat
Voltmeter indicates
Too little voltage
Voltage level provides some indication of remaining battery life

6. Switches and Fuses Master Switch Fuses Circuit Breakers
For normal operation, both switches are on
Switching off the battery will automatically switch off the alternator
If you must switch off either during flight, land as soon as possible
Fuses
A fuse is an over-current protection device
Can not be reset
Metal conductor melts when current is too high
Circuit Breakers
A circuit breaker is an over-current protection device
Can be reset
Pilot should wait 90 seconds before attempting to reset
Only attempt one reset
If you smell smoke or detect burning, do not attempt a reset

7. Hydraulic Systems
Hydraulic systems use fluid pressure to create motion
On General Aviation aircraft, these system most often are used to operate the wheel brakes and retract landing gear
On larger and more complicated aircraft, hydraulic systems are used to move many different surfaces
Leading Edge Flaps
Horizontal Tails
Hydraulic fluid is a very hazardous material and should be handled with great care

8. Heating and Ventilation
See Figure 4-75 page 113
Be familiar with the airflow in the cabin and the controls a pilot has to change the heating and ventilation

9. 3 Types of Pressure Static Pressure Dynamic Pressure Total Pressure
Caused by random motion of gas molecules
Equal in all directions
For the atmosphere, this translates to function of altitude
Dynamic Pressure
Caused when gas molecules have a net resultant velocity (not just random motion)
It is a function of the number of molecules (expressed as density, mass/volume)
It is a function of the resultant net velocity
Pdynamic = 0.5 r V2
Total Pressure
Total pressure is the sum of static and dynamic pressure
Ptotal = Pstatic + Pdynamic

10. Pressure Instruments
The Pitot-Static system measures the total pressure and the static pressure
Since dynamic pressure is the difference between total and static pressures, all three can be known by measuring any 2
Altimeter
See Figure 4-84 page 119
Uses static pressure to indicate altitude
Uses a model of the atmosphere to predict altitude based on static pressure
You must correctly set the subscale (QNH)
Vertical Speed Indicator (VSI)
Uses the rate of change of static pressure to predict altitude rate

11. Pressure Instruments 2 Air Speed Indicator (ASI)
See Figure 4-82 page 118
Uses dynamic pressure to indicate airspeed
Colour coded to rapidly convey important speeds
See Figure 4-83 page 118
Assumes a constant air density
Indicated speed will differ from true airspeed as altitude changes
See Figure 4-78 page 115

12. Gyroscopic Instruments
Gyroscopes use the principles of angular momentum to maintain an orientation
Powered by electricity or a vacuum system
See Figure 4-90 page 123 for vacuum system details
For more info on gyros see:
Follow the links to see more information
The “NASA: Guidance, Navigation and Control” contains some good info on how gyros are used in aerospace applications
Attitude Indicator
See Figure 4-92 page 124
Uses a gravity aligned gyroscope to indicate pitch angle and bank angle

13. Gyroscopic Instruments 2
Heading Indicator
See Figure 4-93 page 124
Uses a gyroscope to indicate heading angle
Must be occasionally realigned due to drift
Turn Indicator
See Figure 4-94 page 125
Uses a gyroscope to sense the rate of turn (heading change)
Turn Coordinator
See Figure 4-95 page 126
Uses a gyroscope to sense both roll and yaw rates

14. Other Instruments Balance Ball Magnetic Compass
Uses gravitational and inertial forces to coordinate a turn
Magnetic Compass
You might think this would be a pretty simple and easy instrument to use: compass points north, gives you your heading
However, there are many precautions you must take when using your compass
Magnetic north is not true north
Know what variation to use
Metal and electrical equipment in the cabin can affect the compass
Know what deviation to use
Turns and accelerating can affect compass indications

15. For next week…
Required Reading: BAK Chapter 5, pp