Aircraft General Knowledge
The VSI uses static pressure only, it works by comparing the changes in pressure. If it became blocked, no change would occur.
Manifold pressure would decrease and then increase after applying carby heat to remove induction icing.
Carb Icing is most likely in a descent at low power
Spark plug detonation occurs as spontaneous explosive combustion. Showing as a decrease in engine power or engine failure. This can be caused by: time-expired fuel, fuel with lower than recommended octane rating, over lean mixture at high settings, excessive manifold pressure or an overheated engine.
An overheated cylinder head temp can be reduced by enriching the mixture (fuel is a coolant), reduce throttle, increase airspeed.
Pre-ignition results are: rough running, back firing, sudden rise in CHT, possibly a broken cylinder head, damaged cylinder wall, spark plugs and valves.
Causes of pre-ignition are: hot spots on the cylinder, using high power when the mixture is too lean or over heated spark plugs.
Aircraft Limitations –
V Speeds
Vle = Maximum landing gear extension
Vfe = Flap Extended Speed (max speed at which flaps can be extended (top of white arc)
Vx = Best Angle of Climb (most altitude the quickest)
Vy = Best Rate of Climb (most altitude over time)
Va = Manoeuvring Speed (max speed for full and abrupt control movements)
Vs = Stalling speed level flight
Vs1 = Stalling speed flaps up, gear up (bottom of green arc)
Vs0 = Stalling speed with flaps down, gear down (bottom of white arc)
Vno = max speed for sudden control movements and turbulence (top of the green arc)
Vne= Never Exceed Speed (structural damage may occur, red line on the ASI)
Vb = Turbulence Speed (max speed at which the aircraft can handle severe vertical gusts)
Vlo = Landing gear operating speed. (Not shown on the ASI)
IAS – speed shown on ASI relative to density of air through pitot tube
CAS - speed shown on ASI after corrections made from instrument & pressure (position error)
TAS – the actual speed over the ground
TORA = Take off Run Available (The length of runway declared available for the ground run of an aircraft)
TODA = Take off Distance Available (The length of take off run declared plus any clearway available)
Take Off Safety Speed = Leaves adequate control in the event of an engine failure during the climb after takeoff)
LDA = The length of runway declared available for the landing run of an aircraft
Air Law: - Refer to VFG (Visual Flight Guide)
Carriage of infants and small children:
Two children aged between 3 and 13 years whose combined weight does not exceed 77KG may be seated in one passenger seat.
An aircraft flying over the open countryside must always maintain a minimum flight level of 500ft AGL.
Flight notification form can be submitted via radio to ATS in brief on departure if the flight is local and VFR.
Maintain height and heading but be prepared to take action to avoid a collision if the aircraft is converging from my left.
VFR flight within Australia is restricted to operations outside Class A controlled airspace.
Unless exempt, a flight notification and reporting requirement for flights through ADIZ, is a position report shall be made immediately prior to entry into the ADIZ.
A flight is exempt from the general requirements of an ADIZ if the flight is within 10nm of its point of departure.
Refuelling operations from a fixed point must stop, when a quantity of fuel is spilled until the spillage has been removed.
Separation Minima”
An aircraft will not be permitted to take off until the preceding aircraft at a non towered aerodrome is:
Crossed the upwind end of the runway;
Commenced a turn;
If the runway is longer than 1800m, has become airborne and is at least 1800m ahead of the following aircraft;
If the aircraft has an MTOW of 7000KGs or less and the preceding aircraft has an MTOW below 2000KG the aircraft is airborne and at least 600M ahead of the following aircraft;
If both aircraft have MTOW below 2000KG the aircraft must be airborne and at least 600M from the end of the runway.
If voice is available on a NDB and you have a comms failure, squawk code 7600, select the ADF to phones or speaker as applicable, turn up the volume and listen for instructions.
Cargo must always be secured in aircraft with a MTOW less than 5700KG.
One condition applying to the carriage of a person on a stretcher is that both the person and the stretcher must be secured against the accelerations of movement in an n emergency and normal flight.
A mercy flight can only be declared if it will involve irregular operation such as the breaking of a regulation.
Within an ADIZ, an intercepting aircraft performs a 90 degree climbing turn without crossing the line of flight of the intercepted aircraft which means you may proceed with your flight.
Aerodynamics:
Take off distance will be increased by a decrease in atmospheric pressure; this will cause a decrease in density altitude. High humidity also increases take off distance as the water molecules push the gas molecules out of the way, again reducing atmospheric density.
Factors that affect stalling speed- weight – speed – flap
The indicated airspeed at which a plane stalls will be the same regardless of altitude
An increase in load factor will cause a stall at a higher airspeed
A forward CG equals a higher stall speed
Am aircraft in a 30deg bank stalls at a 7% higher speed
A rear CG equals a lower stall speed
Aileron that goes down causes that wing to go up and yaw back
An increase in headwind will increase landing distance on an asphalt runway due to more lift.
An affect of loading the aircraft forward of the forward limit is that it may become too stable.
Product of the weight of an item and its horizontal distance from the datum is called the moment.
Take off into a headwind leads to increased climb gradient and increased airspeed.
Taking off with an increasing tailwind has the effect of decreasing the airspeed and decreasing the climb angle.
Descending with a decreasing tailwind, or an increasing headwind or an updraught (thermal) the airspeed will show a sudden increase and a decrease in descending angle.
GROUND EFFECT is extra lift close to the ground, it will allow lift off at low speeds but unable to get airborne until the IAS is increased.
An aerofoil is at its stalling angle if any increase or decrease in its angle of attack results in less lift.
Descending with a decrease in headwind, an increase in tailwind, or a down drought from a thunderstorm, will cause the aircraft to show a decrease in airspeed, and an increase in rate of descent.
Reduction in weight or an increase in airspeed will decrease the stall speed.
Frost on a wing will cause the stall speed to increase due to the rough surface not allowing a smooth flow of air resulting in reduced lift.
The magnitude of the lift force will increase as the angle of attack is of an aerofoil is increased towards the stalling angle.
Temp in the combustion chamber changes instantly with changes in the fuel/air ratio. The exhaust gas gauge (EGT) registers this rapidly. The cylinder head temp (CHT) changes slower due to the mass of the metal.
Excessive priming washes the oil off the cylinder walls allowing metal to touch metal increasing the possibility of damage.
If the static air vent was blocked from take off, the pressure would be trapped in the system causing the ASI too slowly under read as the density of air in the Pitot tube reduces.
Navigation:
One in 60 Rule
Multiple the distance off track by 60 and then divide by the length of the distance travelled.
TE = Distance off track * 60 / Distance Travelled
CA = Distance off track * 60 / Distance to go
TTI = TE + CA
TMG = FPT + TE
DRIFT = Difference between TMG & HDG held (left or Right)
HDG after intercept = FPT + DRIFT Correction
PH = ALT + ((QNH – 1013)*30)
Density = 1degree produces 120ft
ISA = 15 – (2x thousands of feet)
DH = PH + (ISA deviation *120)
Standard Atmosphere = 1013.25
ISA at Tropopause = -56.5c
Tropopause = 28250 feet
ADF & NDB:
Fixed Card ADF – TO the station = HDG + BearingR(R being relative to the aircrafts nose)
- FROM the station = HDG + BearingR – 180
Interference can be made by Night Effect – Sky wave inference especially at night
Thunderstorm effect
Co Channel interference – other transmitters transmitting ion the same frequency
Mountain Effect –reflections of the NDB signal from mountains causes a decrease in strength
Coastal Refraction – distortion as the signal passes from one surface to another
Quadrantal Error – interference from the aircraft structure
To work out the drift, turn the ADF card to 000 and follow the difference between the arrow and the heading.
Tune Identify Test
FROM NDB subtract 180
VOR:
Sends signal in radials
CDI needs to be cantered and either TO or FROM indication
Course deviation indicator 2deg per DOT
Beginning of Daylight/End of Daylight
Using the ERSA:
Find the Longitude and Latitude
Using the BOD/EOD Chart
Use the Latitude position on the BOD/EOD Chart
Use the date on the chart
Read across to the LMT
Using the Longitude, convert Arc to Time using the tables
Subtract Arc time from the LMT
Then convert to UTC
UTC Australia
EST - UTC+ 10
CST - UTC + 9.5
WST - UTC +8
Using the computer:
To convert fuel:
Litres to US Gallons- place the number of gallons under the US Gallon label on the outer slide
Then read off the equivalent in litres from under the Litres label on the outer slide
To convert distance:
KM to NM- Set the known distance under Naut or KM marking, then read off the required distance conversion under the correct label.
To find density altitude:
Find the pressure height, and then place the pressure altitude to correspond with the OAT and then read off the density altitude using the pointer.
Headwind component:
Work out the distance between the runway heading and the wind direction in degrees. Then follow the number of degrees line on the chart down to the wind velocity line. Then read off the HW and CW components.
Heading & Groundspeed:
First place the true wind under the index. Then mark the wind velocity with a dot. Spin the azimuth to the true heading, and then slide the wind velocity mark up to the true airspeed.
Read the ground speed under the centre grommet and then add or subtract the degrees to the heading to get the heading in degrees true. Then apply the magnetic variation, west is best east is least.
TIP: Convert all headings, winds and tracks to magnetic FIRST!
Magnetic variation:
East = least West = Best
Meteorology:
The sun’s rays heat the earth most intensely near the equator. The surface becomes hot and the air begins to rise and because it is mostly ocean at the equator, there is a significant amount of water vapour which condenses to form extensive cloud.
At the tropopause the air stops rising and begins to move horizontally towards the poles, as it moves it cools and begins to sink.
SINKING AIR = High Pressure at surface
RISING AIR = Low Pressure at surface
Equatorial Trough – Belt of low pressure near the equator, cloudy, frequent rain
Sub Tropical Ridge – Belt of high pressure between tropical & sub tropical cells, relatively free of cloud
Polar Front – Low pressure which separates the cold polar air from the warmer sub tropical air, cold polar air frequently breaks free and sweep northward to produce cold fronts affecting the southern part of Australia in winter
Polar High-The sinking cold air over the poles produces a permanent high pressure region
Each belt is made up of families of lows and highs that move between the cells.
Vertical Air Movement & Surface Pressure
Pressure on the earth’s surface is due to the weight of the air pressing down on that point.
CORIOLIS EFFECT – Sinking air with the rotation of the earth in the southern hemisphere spirals to the left in an ANTICLOCKWISE direction and is a HIGH Pressure System or Anticyclone (due to high pressure at the surface)
Rising air moves in a CLOCKWISE direction and is called a LOW pressure system (due to the low pressure left at the surface)
SYNOPTIC CHARTS
The sea level pressure at any point along thee isobar is equal to the number printed on it. In Australian latitudes, the approximate wind direction can be estimated from the chart as parallel to the isobars, clockwise about a low and anticlockwise about a high.
The air in the vicinity of a high is sinking and the air in the vicinity of a low is rising.
Pressure Gradient
Air flows out of a high pressure into a low under the influence of a pressure gradient. The amount by which the height changes in a given horizontal distance determines the gradient of the slope.
The amount by which the pressure changes over a given horizontal distance determines the pressure gradient.
Pressure gradient determines wind speed!
Isobar spacing reveals the strength of the pressure gradient.
SYNOPTIC FEATURES
A RIDGE – Elongated isobars about a high like a finger
A TROUGH – Elongated isobars about a LOW like a finger
A COL – Area between two highs and two lows
Isobar spacing is usually 4hPa but could be 2hPa
TERMS FOR DESCRIBING WIND FLOW
GRADIENT FLOW – wind is moving directly along the isobar
SURFACE WIND – Wind speed is decreased by friction. Wind swings across the isobar in favour of the pressure gradient. ALWAYS to the RIGHT of the GRADIENT WIND
BUYS BALLOTS LAW – Back to the wind in the southern hemisphere, the lowest pressure will always be at the right hand
Surface wind in a low will be deflected into the system; surface wind in a high will be deflected out of the system.
CHANGES IN WIND DIRECTION – BACKING & VEERING
The wind is backing to the left, and veering to the right.
The change in speed and direction-
Over Land: surface wind drops by two thirds and direction veers by 30degrees
Over Sea: surface wind drops by one third and veers by 10degrees
LOCAL WINDS
SEA BREEZES- cooler than land breezes during the day as the land heats by conduction the air rises and causes a low pressure which the high pressure of sinking air over the ocean moves towards. The effect is strongest when the temperature difference is greatest i.e. mid afternoon in summer occur during the day
LAND BREEZES – at night time, the land cools and the air sinks towards the earth creating a high pressure which moves the wind towards the low pressure in the sea caused by the warmer air rising. Morning is the most prevalent.
KATABATIC WINDS - From Greek word meaning “go down.” Unlike all other winds, these winds are a result of gravity and occur where there are very steep gradients. Such as an area with a very high plateau of land dropping away steeply to the sea. Prevalent in the mornings!
ANABATIC WINDS – From the Greek word meaning to “go up.” Opposite of Katabatic winds these go up the sloping terrain, prevalent in the afternoons!
FOHN WIND – Moist wind coming from the ocean cools as it rises up the slope of a mountain and the water vapour condenses to form cloud on the windward side. This cloud is called OROGRAPHIC
CLOUD- When the water vapour condenses, heat is released into the environment air which then continues down the lee side of the slope minus the water vapour.
GUSTS & SQUALLS – Temporary & sudden changes in average wind velocity. Main difference is magnitude and duration of the change.
A squall must have a wind change by at least 16knt to reach 22knt or more and be sustained for more than one minute.
A gust is a sudden change of less magnitude and duration, it changes rapidly and then slackens off back to the average speed.
METEOROLOGICAL PROCESSES
WATER IN THE ATMOSPHERE CHANGING STATES
3 states of water:
ICE – Water molecules are in a fixed position next to its neighbour.
LIQUID – Water molecules can move within the body.
VAPOUR - Water molecules can move anywhere.
SOLID to LIQUID – Melting or Fusion (requires heat)
LIQUID to VAPOUR – Evaporating (requires heat)
SOLID to VAPOUR – Sublimation (requires heat)
VAPOUR to LIQUID – Condensation (heat released)
LIQUID to SOLID – Solidifiction (heat released)
VAPOUR to SOLID – Deposition (heat released)
HUMIDITY & DEW POINT TEMPERATURE
CLOUD TYPES
HIGH CLOUDS
Cirrus
MIDDLE CLOUDS
LOW CLOUDS
A destination TAF should be valid from 30 min before and 60 min after the planned ETA.
Winds are given in degrees TRUE
Cloud heights are given AMSL
Clear
FEW 1-2 OKTAS
SCT 3-4 OKTAS
BKN 5-7 OKTAS
OVC 8 OKTAS
Area Forecasts have the cloud height give AMSL
A COL is an area between 2 highs and 2 lows, light and variable winds are often associated with COL’s with a FOG possibility in winter. In summer they tend to produce high temps and showers.
A land breeze is more likely to occur just before sunrise when the greatest temp difference between the land and the sea.
A sea breeze is a likely to occur in the early or mid afternoon when the greatest temp difference between the land and the sea. The land heats up more during the day.
HUMAN FACTORS
The leans are a specific affect of turns. The pilot feels like the turn is in the opposite direction, this occurs when a pilot levels the wings after a long turn rapidly.
Hypoxia is not enough oxygen
Hyperventilation is too much oxygen
Family history of premature heart disease is the most serious risk factor.
Noise induced hearing loss results from over stimulation of the hairs in the cochlea. Continued over stimulation can destroy hair cells.
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