ICAA CPL Theory cheat sheet

VFR minima in Class C/D airspace at or above 10,000 ft AMSL: 8 km flight visibility, 1,500 m horizontal and 1,000 ft vertical distance from cloud.

VFR minima at or below 3,000 ft AMSL: 5 km flight visibility, clear of cloud and in sight of the surface.

Aircraft must be operated within 90 days of the last biennial flight review for the pilot to carry passengers.

Right-of-way: converging aircraft of the same category give way to the one on the right; a lower aircraft gives way to a higher aircraft except when descending.

A controlled flight must not enter Class C airspace without a clearance; Class D requires a clearance for IFR and two-way radio contact for VFR.

Aircraft registration marks must be displayed on the fuselage or vertical tail, with letters at least 30 cm high on larger aircraft.

The pilot-in-command is responsible for ensuring the aircraft is airworthy and that all required documents (certificate of registration, airworthiness, radio licence, insurance) are on board.

Aircraft may not be flown below 500 ft above ground level except when taking off or landing, or with CASA approval.

Alcohol limit: no pilot may act as crew with a blood alcohol concentration of 0.02% or greater, or within 8 hours of consuming alcohol.

Four-stroke engine cycle: intake, compression, power, exhaust; the crankshaft completes two revolutions per cycle.

Detonation is uncontrolled explosive combustion causing high cylinder pressures and temperatures; pre-ignition is ignition before the spark.

The mixture control adjusts fuel-to-air ratio; lean for high density altitude and rich for low density altitude or high power settings.

Carburettor icing is most likely at temperatures between -5°C and +15°C with high relative humidity; use carburettor heat to prevent or clear it.

The altimeter measures static pressure; setting QNH gives altitude above mean sea level, QFE gives height above a reference datum, QNE (1013.2 hPa) gives flight level.

Airspeed indicator uses pitot (total pressure) and static pressure; blockage of the pitot tube causes the ASI to act like an altimeter.

The turn coordinator shows rate of turn and includes an inclinometer to indicate slip or skid; the attitude indicator shows pitch and bank.

Hydraulic system failure in a light aircraft typically affects flaps and brakes; the landing gear may be extended manually.

Electrical system: the battery provides power for starting and emergency; the alternator/generator charges the battery and powers the electrical load.

Density altitude increases with high elevation, high temperature, and high humidity, degrading aircraft performance.

Take-off distance increases with higher density altitude, tailwind, upslope, and higher aircraft weight.

Landing distance increases with higher density altitude, tailwind, downslope, and higher aircraft weight.

Weight and balance: the centre of gravity must remain within the forward and aft limits for all phases of flight.

Fuel planning: reserve fuel for VFR is 30 minutes by day and 45 minutes by night (or as specified by the operator).

Climb gradient (%) = (altitude gain / horizontal distance) × 100; rate of climb (ft/min) = climb gradient × groundspeed (kt) × 101.3 / 60.

Endurance (hours) = usable fuel (kg) / fuel consumption (kg/h); range (nm) = endurance × true airspeed (kt).

Crosswind component = wind speed × sin(wind angle); headwind component = wind speed × cos(wind angle).

Pressure altitude = indicated altitude + (1013.2 − QNH) × 30 ft per hPa.

Hypoxia symptoms: euphoria, impaired judgement, blurred vision, cyanosis; time of useful consciousness decreases with altitude.

Hyperventilation causes dizziness, tingling, and muscle spasms; treat by slowing breathing rate and increasing carbon dioxide.

Spatial disorientation: rely on instruments, not bodily sensations, when visual references are lost.

The eye's rods are sensitive to dim light and are located in the periphery; cones provide colour vision and detail in bright light.

Carbon monoxide poisoning causes headache, drowsiness, and confusion; use cabin heat sparingly and ensure ventilation.

Fatigue degrades alertness and decision-making; rest and proper sleep are the only effective remedies.

Decompression sickness (the bends) occurs with rapid altitude changes; avoid flying after diving (minimum 24 hours after diving).

Stress and workload: use prioritisation and delegation; the pilot's capacity to handle tasks decreases under high stress.

Alcohol impairs judgement and reaction time; effects persist after BAC returns to zero.

Standard atmosphere: sea level pressure 1013.2 hPa, temperature 15°C, lapse rate 2°C per 1,000 ft up to 36,000 ft.

QNH is the pressure reduced to sea level; QFE is the pressure at the aerodrome reference point; QNE is 1013.2 hPa.

Cloud types: cumulus (convective), stratus (layered), cirrus (high ice), nimbostratus (continuous rain).

A cold front brings rapid weather changes, thunderstorms, and strong gusty winds; a warm front brings gradual cloud and continuous rain.

Icing risk is highest in stratiform clouds at temperatures between 0°C and -20°C; clear ice forms in cumuliform clouds.

Wind shear is a sudden change in wind speed or direction; most dangerous during take-off and landing.

Thunderstorms require three conditions: moisture, instability, and a lifting mechanism; avoid flying under or near them.

Fog forms when the air is cooled to its dew point; radiation fog forms on clear calm nights, advection fog when warm moist air moves over a cold surface.

The Coriolis force deflects wind to the left in the Southern Hemisphere; surface friction reduces wind speed and causes it to cross isobars toward low pressure.

True north is the direction to the geographic North Pole; magnetic north is the direction to the magnetic pole; variation is the angle between them.

Compass deviation is the error caused by the aircraft's magnetic fields; it is specific to each aircraft and heading.

Track is the path over the ground; heading is the direction the aircraft points; drift is the angle between heading and track.

Wind correction angle = arcsin( (wind speed / true airspeed) × sin(wind angle) ).

Groundspeed = true airspeed × cos(wind correction angle) + wind speed × cos(wind angle).

Time = distance / groundspeed; fuel required = time × fuel consumption rate.

1 nautical mile = 1.852 km; 1 knot = 1 nautical mile per hour.

The 1-in-60 rule: a 1° error in heading results in 1 nautical mile offset after 60 nautical miles.

GNSS provides position, track, and groundspeed; RAIM (Receiver Autonomous Integrity Monitoring) is required for certain approaches.

Before take-off: complete pre-flight inspection, check weather, NOTAMs, weight and balance, and performance calculations.

Emergency procedures: engine failure after take-off - lower the nose to maintain airspeed, land ahead or within 30° of the nose.

Fire in flight: shut off fuel and electrical, use fire extinguisher, and land as soon as possible.

Radio failure: squawk 7600, continue VFR and land at the nearest suitable aerodrome; for IFR follow the published lost communication procedures.

Passenger briefing must include seat belts, emergency exits, oxygen, and no smoking.

Use of checklists: read and respond to each item; never rely on memory for critical items.

Wake turbulence: avoid the flight path of larger aircraft; stay above and upwind; wait at least 2 minutes after a heavy aircraft departs.

Runway incursion: never enter a runway without clearance; use standard phraseology and read back clearances.

Lift = ½ ρ V² S CL; lift increases with air density, speed squared, wing area, and lift coefficient.

Induced drag decreases with speed; parasite drag increases with speed squared; total drag is minimum at the speed for best glide.

The critical angle of attack is the angle at which the wing stalls; it is independent of weight, speed, and bank angle.

Load factor increases in turns: n = 1 / cos(bank angle); stall speed increases with the square root of the load factor.

The four forces: lift, weight, thrust, and drag; in steady level flight lift equals weight and thrust equals drag.

Aspect ratio = wingspan² / wing area; higher aspect ratio reduces induced drag.

The centre of pressure moves forward as angle of attack increases; the centre of gravity affects stability.

Mach number = true airspeed / speed of sound; critical Mach number is the free-stream Mach number at which airflow over some part of the aircraft reaches Mach 1.

Longitudinal stability is provided by the horizontal stabiliser; dihedral provides lateral stability.

Standard phraseology: use ICAO standard words and phrases; read back clearances and runway instructions.

Emergency frequencies: 121.5 MHz for VHF; 243.0 MHz for military UHF.

Transponder codes: 7700 (emergency), 7600 (radio failure), 7500 (unlawful interference).

Call sign: use aircraft type and last three letters of registration (e.g., Cessna 12345).

Position report: aircraft identification, position, time, altitude, next position and ETA.

Radio failure: squawk 7600, continue VFR and land at the nearest suitable aerodrome; for IFR follow published procedures.

Use of QNH and QFE: QNH for altitude above sea level, QFE for height above aerodrome.

Readability scale: 1 unreadable, 3 readable with difficulty, 5 perfectly readable.

Distress call: MAYDAY (spoken three times); urgency call: PAN-PAN (spoken three times).