CARC CPL Theory cheat sheet

ICAO Annex 2 classifies airspace as controlled (A–E) or uncontrolled (F–G); Class A permits IFR only, Class G permits both with no ATC clearance.

VFR meteorological minima in controlled airspace at/above 3,050 m AMSL: 8 km visibility and 1,500 m horizontal, 300 m vertical cloud distance.

Right-of-way: converging aircraft of the same category - the one on the right has right-of-way; head-on - both turn right; overtaking - the overtaken aircraft has right-of-way.

An aircraft in distress has right-of-way over all other traffic; give way to balloons, gliders and airships, and to aircraft towing or refuelling.

VMC minimum visibility below 900 m AMSL is 5 km; between 900 and 3,050 m it is 5 km with cloud clearance of 1,500 m horizontal and 300 m vertical.

Anti-collision lights must be on for all flights; landing lights at night; navigation lights show red left, green right, white aft.

Squawk 7500 = unlawful interference, 7600 = radio failure, 7700 = emergency; these codes override assigned codes.

Aircraft must carry documents: certificate of registration, airworthiness, crew licences, journey log, and radio licence where applicable.

Wing loading = weight ÷ wing area; higher wing loading raises stall speed and improves gust penetration but increases take-off and landing speeds.

Aspect ratio = span² ÷ wing area; higher aspect ratio reduces induced drag but increases structural bending loads.

Dihedral gives lateral stability; anhedral is used on high-wing or swept-wing aircraft to offset excessive stability.

A four-stroke cycle: intake, compression, power, exhaust; the power stroke occurs once per two crankshaft revolutions.

Carburettor icing is most likely at ambient temperatures between −5 °C and +15 °C with high relative humidity; apply carburettor heat before ice forms.

Detonation is uncontrolled explosive combustion; pre-ignition is ignition before the spark - both cause high cylinder head temperature and power loss.

Fuel/air mixture: lean mixture raises exhaust gas temperature and cylinder head temperature; rich mixture cools the engine and increases power up to a point.

The pitot-static system: static port feeds altimeter, VSI and airspeed indicator; pitot pressure feeds only the airspeed indicator.

Density altitude rises with high elevation, high temperature and high humidity; it increases take-off and landing distances and reduces climb performance.

Centre of gravity forward of the limit increases stall speed and reduces elevator authority; aft of the limit reduces longitudinal stability.

Load factor n = 1 ÷ cos(bank angle); at 60° bank load factor is 2, and stall speed increases by √n (about 41 % at 60°).

Stall speed in a turn: V_s(turn) = V_s × √(1 ÷ cos φ).

Maximum range is achieved near best lift/drag ratio; maximum endurance is achieved at minimum power required speed.

Take-off distance varies approximately with the square of the weight ratio for a given configuration.

Moment = weight × arm; total moment divided by total weight gives the CG position in the same units as the arm.

Wind effect: headwind increases climb gradient over the ground and shortens ground roll; tailwind does the opposite.

Hypoxia symptoms: euphoria, impaired judgement, cyanosis, headache; time of useful consciousness at 25,000 ft is about 1–2 minutes.

Hyperventilation causes dizziness and tingling; treat by slowing breathing rate and, if in doubt, assume hypoxia and use supplemental oxygen.

Spatial disorientation: trust instruments, not sensations; the leans and somatogravic illusion are common in low-visibility departures.

Crew resource management: assertiveness, situational awareness, workload distribution and closed-loop communication reduce error chains.

Decision models: DECIDE (Detect, Estimate, Choose, Identify, Do, Evaluate) and the 3P model (Perceive, Process, Perform).

Fatigue degrades reaction time and vigilance; circadian low points occur around 03:00–06:00 and 15:00–17:00 local time.

IMSAFE checklist: Illness, Medication, Stress, Alcohol, Fatigue, Emotion/Eating.

ISA: sea level temperature 15 °C, pressure 1013.25 hPa, lapse rate 1.98 °C per 1,000 ft up to 36,090 ft.

QNH is pressure reduced to sea level; QFE is pressure at aerodrome elevation; QNE is 1013.25 hPa used above transition altitude.

Isobar spacing indicates pressure gradient: close isobars mean strong wind; wind blows along isobars with low pressure to the left in the Northern Hemisphere.

In the Northern Hemisphere, wind veers with height in the friction layer; surface wind is backed relative to geostrophic wind.

Cumulonimbus hazards: severe turbulence, hail, icing, microbursts, lightning; avoid by at least 10 nm laterally.

Fog forms when the dewpoint spread is small and the air cools to saturation; radiation fog forms on clear, calm nights.

Freezing rain indicates a warm layer aloft over sub-freezing air; structural icing risk is highest at 0 to −20 °C in visible moisture.

Altimeter setting: flying from high to low pressure without adjusting the subscale causes the aircraft to fly lower than indicated.

True bearing = magnetic bearing + variation (east add, west subtract); magnetic heading = true heading − variation.

Compass deviation is aircraft-specific and applied after variation: magnetic heading ± deviation = compass heading.

1 in 60 rule: a 1 nm lateral error over 60 nm equals a 1° track error.

Great circle is the shortest path on a sphere; rhumb line is a constant-track line, longer except along the equator or meridians.

VOR gives magnetic bearing from the station (radial); DME gives slant range; TACAN combines both.

ILS categories: CAT I decision height 200 ft, CAT II 100 ft, CAT III down to zero decision height with autoland.

NDB/ADF indicates relative bearing; the ADF needle points to the station regardless of aircraft heading.

GPS RAIM ensures integrity; without RAIM the receiver cannot guarantee position accuracy for the required phase of flight.

Distress call: MAYDAY, MAYDAY, MAYDAY; urgency call: PAN-PAN, PAN-PAN, PAN-PAN; both repeated three times.

Standard readback required for clearances, runway assignments, altimeter settings, headings, altitudes and frequencies.

Phonetic alphabet: Alpha, Bravo, Charlie, Delta, Echo, Foxtrot, Golf, Hotel, India, Juliett.

Numbers are transmitted digit by digit, except whole hundreds and thousands: 1,200 ft = "one thousand two hundred feet".

Frequency change: "(Station), (callsign), request frequency change"; acknowledge with callsign.

Emergency frequency 121.5 MHz; guard frequency monitoring is required when directed.

Lost communication: squawk 7600, continue per last clearance or VMC rules, and land at the nearest suitable aerodrome.

Position report format: callsign, position, time, altitude, next position and ETA, followed by the next significant point.