GCAA CPL Theory Exam (GCAA) cheat sheet

ICAO Annex 2 classifies airspace A–G: Class A is IFR only with all aircraft separated; Class G is uncontrolled with no ATC separation service for IFR or VFR.

Semicircular rule (Annex 2, magnetic track): 000–179° use odd flight levels (FL 090, 110, 130...); 180–359° use even flight levels (FL 100, 120, 140...).

VFR minima in Class C–E above 900 m (3000 ft) AMSL: 8 km flight visibility, 1500 m horizontal and 300 m (1000 ft) vertical distance from cloud.

VFR minima at and below 900 m AMSL: 5 km flight visibility, clear of cloud with surface in sight; ICAO permits states to reduce visibility to 1500 m at speeds of 140 kt or less.

VMC minima in Class F/G above 900 m: 5 km visibility, 1500 m horizontal and 300 m vertical cloud distance; at or below 900 m: 5 km, clear of cloud, surface in sight.

Aircraft must carry documents: certificate of registration, certificate of airworthiness, crew licences, journey log, and (for radio-equipped aircraft) radio station licence.

Annex 2 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.

Controlled airspace clearance must be obtained before entry; position reports are required at compulsory reporting points and when instructed by ATC.

Aircraft must not fly over congested areas below the altitude permitting a safe emergency landing without endangering persons or property; ICAO does not prescribe a single numeric minimum.

Reciprocating engine four-stroke cycle: intake, compression, power, exhaust; two crankshaft revolutions per complete cycle, one power stroke per cylinder per cycle.

Detonation (knock) results from excessive pressure/temperature in the cylinder; pre-ignition is ignition before the spark - both cause power loss and possible engine damage.

Mixture control: lean for altitude (less dense air), rich for take-off and descent; excessively lean mixture raises cylinder head temperature and risks detonation.

Constant-speed propeller: governor regulates oil pressure to change blade angle; increasing pitch (coarser) reduces RPM, decreasing pitch (finer) increases RPM.

Carburettor icing risk is highest at temperatures between roughly −7 °C and +21 °C with high relative humidity; apply carburettor heat to melt ice before full closure.

Electrical system: alternator supplies DC through a rectifier/regulator; battery provides starting current and standby power; ammeter indicates charge/discharge.

Hydraulic system: pressure generated by engine-driven pump, stored in accumulator, protected by relief valve; check pressure before flight and after gear/flap operation.

Pitot-static system: pitot tube feeds airspeed indicator; static port feeds altimeter, VSI and airspeed; blockage of static causes altimeter freeze and airspeed errors.

Landing gear: check down-and-locked indications (lights, mechanical indicators) before landing; hydraulic or electrical failure requires manual extension procedure.

Density altitude = pressure altitude + 120 × (OAT − ISA temperature at that level); ISA lapse rate is 2 °C per 1000 ft.

Take-off and landing distances increase with altitude, temperature, weight and tailwind; use the aircraft flight manual (AFM/POH) charts for each specific type.

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

Weight and balance: compute moment = weight × arm; CG = total moment ÷ total weight; CG must lie within the forward and aft limits for the take-off and landing configurations.

Fuel planning: trip fuel + taxi + contingency (typically 5 % of trip) + alternate + final reserve (30 min at holding speed for turbine, 45 min for piston under ICAO Annex 6).

Maximum endurance occurs at the speed for minimum fuel flow; maximum range occurs at a higher speed (best lift/drag ratio for propeller aircraft).

Climb gradient (%) = (altitude gain ÷ horizontal distance) × 100; required climb gradient must be met at the planned weight and conditions.

Pressure altitude = indicated altitude corrected for subscale setting; true altitude = pressure altitude corrected for temperature error (higher than ISA → true altitude higher).

Runway slope affects take-off distance: uphill slope increases ground roll; downhill decreases ground roll but may reduce acceleration margin.

Hypoxia symptoms: euphoria, impaired judgement, headache, cyanosis, tingling; time of useful consciousness at FL 350 is about 30–60 seconds, at FL 250 about 3–5 minutes.

Hyperventilation causes dizziness and tingling; treatment is to slow breathing and, if in doubt, treat as hypoxia by using oxygen.

Spatial disorientation: vestibular illusions include the leans, somatogravic illusion (false climb/descent) and coriolis illusion; trust instruments over sensations.

Night vision uses rods (peripheral, low acuity, slow adaptation ~30 min); avoid bright light and use red lighting to preserve dark adaptation.

Cabin altitude above 10 000 ft reduces oxygen saturation; pressurised aircraft maintain cabin altitude typically at or below 8000 ft.

Fatigue degrades reaction time and vigilance; circadian low points are roughly 02:00–06:00 and 14:00–16:00 local time, increasing error rates.

Stress: moderate arousal improves performance; excessive stress narrows attention and increases error; use checklists and standard calls to reduce workload.

Decompression sickness (bends) risk increases with altitude exposure and repetitive dives; flying after diving requires surface intervals per the applicable guidance.

Communication: readback of clearances and standard phraseology reduce misunderstanding; use closed-loop communication for critical instructions.

ISA: sea-level temperature 15 °C, pressure 1013.25 hPa, lapse rate 1.98 °C/1000 ft (2 °C/1000 ft), tropopause at about 36 000 ft.

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

Altimeter setting: flying from high to low pressure without resetting causes the altimeter to read higher than true altitude (dangerously low actual altitude).

Cloud types: cumulonimbus - thunderstorms, icing, turbulence; stratus - low ceiling, drizzle; cirrus - high, ice crystal, fair weather.

Icing risk: clear ice from supercooled large droplets in freezing rain; rime ice from small droplets; highest risk at −2 °C to −20 °C in stratiform clouds.

Thunderstorm life cycle: cumulus (updrafts), mature (updrafts and downdrafts, hail, lightning, gust front), dissipating (downdrafts). Avoid by at least 20 NM.

Wind shear and microburst: sudden change in wind speed/direction; microburst downdrafts can exceed 6000 ft/min; escape by pitching to go-around attitude and applying full power.

Fog types: radiation fog forms on clear calm nights over moist ground; advection fog forms when warm moist air moves over a cold surface; frontal fog at frontal boundaries.

METAR/TAF: wind direction and speed (gusts with G), visibility, cloud base in feet, temperature/dewpoint; QNH in hPa or inHg; CAVOK means visibility ≥ 10 km, no cloud below 5000 ft or MSA, no significant weather.

Great circle: shortest path on a sphere; rhumb line: constant track crossing all meridians at the same angle; Mercator charts show rhumb lines as straight lines.

1 minute of latitude = 1 nautical mile (1852 m); 1 minute of longitude = 1 NM × cos(latitude).

Track = course over ground; heading = direction aircraft points; drift = track − heading; wind correction angle applied to maintain track.

True airspeed (TAS) increases with altitude for a given IAS; rule of thumb: TAS ≈ IAS × (1 + 0.02 × altitude in thousands of feet).

Dead reckoning: GS = distance ÷ time; time = distance ÷ GS; fuel = fuel flow × time; use the navigation computer (E6B) for wind triangle solutions.

VOR: radials are magnetic bearings from the station; CDI centres when the selected OBS matches the radial; TO/FROM indicator shows the direction relative to the station.

NDB/ADF: relative bearing + heading = magnetic bearing to station; ADF points to the station; no station passage indicated by needle swing.

GPS: RAIM (receiver autonomous integrity monitoring) detects satellite faults; required for IFR approaches; check RAIM prediction before flight.

Magnetic variation: true to magnetic - east variation is subtracted (east is least); magnetic to true - east variation is added.

Pre-flight: check NOTAMs, weather, fuel, weight and balance, aircraft documents, and performance data before departure.

Emergency checklist priority: aviate, navigate, communicate; memory items for critical emergencies (engine failure, fire) followed by checklist confirmation.

Engine failure after take-off: maintain control, pitch for best glide speed (or VY), select landing site, attempt restart per checklist, broadcast MAYDAY if unable to restart.

Fire: shut off fuel, mixture and electrical supply to affected engine; discharge fire extinguisher; land as soon as practicable.

Emergency descent: oxygen masks on, descend to 10 000 ft or MSA, notify ATC, turn off pressurisation outflow if applicable.

Ditching: prepare life jackets, brief passengers, transmit MAYDAY with position and intentions, land into wind with minimum speed and flaps as required.

Runway incursion prevention: read back hold-short instructions, confirm runway entry clearance, use exterior lights and sterile cockpit during taxi.

Volcanic ash: avoid; if encountered, reduce thrust, turn 180°, and report to ATC; ash damages engines and pitot-static system.

Accident/incident reporting: report to the state of occurrence per ICAO Annex 13; preserve evidence and record relevant data.

Lift = ½ ρ V² S CL; drag = ½ ρ V² S CD; lift increases with air density, speed squared and angle of attack (up to the critical angle).

Angle of attack is the angle between the chord line and the relative airflow; stall occurs at the critical angle of attack regardless of speed, weight or attitude.

Induced drag decreases with speed (proportional to 1/V²); parasite drag increases with V²; total drag minimum at the speed for best L/D.

Load factor n = L/W; stall speed increases with √n - at 60° bank n = 2, stall speed increases by about 41 %.

Stability: positive static stability returns to equilibrium after disturbance; positive dynamic stability dampens the oscillation; CG forward increases longitudinal stability.

Bernoulli and Newton: pressure differences and downward momentum both contribute to lift; the wing produces downwash and trailing vortices.

Critical Mach number: first point where local airflow reaches Mach 1; shock waves form and drag rises steeply (Mach tuck, buffet).

Flaps increase lift and drag, lowering stall speed; leading-edge devices (slats) delay stall by increasing critical angle of attack.

Turns: rate of turn depends on bank angle and speed; load factor increases with bank; standard rate turn is 3°/s (180° in one minute).

Standard readback: aircraft call sign, clearance limit, route, altitude, heading, speed, frequency; read back hold-short instructions and runway assignments.

Phonetic alphabet: Alpha, Bravo, Charlie, Delta, Echo, Foxtrot, Golf, Hotel, India, Juliett, Kilo, Lima, Mike, November, Oscar, Papa, Quebec, Romeo, Sierra, Tango, Uniform, Victor, Whiskey, X-ray, Yankee, Zulu.

Numbers: transmit digits individually; 9 as NINER, 5 as FIFE, 3 as TREE; altitude in feet with group form (e.g., FL 350 = "flight level three five zero").

MAYDAY (distress) and PAN PAN (urgency) prefixes; MAYDAY repeated three times for distress; include position, altitude, nature of emergency, intentions.

Position report elements: call sign, position, time, altitude/flight level, next position and ETA, next significant point.

VFR flight plan: file before departure; activate with ATC or FSS; close after landing; failure to close may trigger search and rescue.

IFR clearances: read back the full clearance; if unable to comply, state "UNABLE" and request amended clearance; do not deviate without ATC approval except in emergency.

Transponder codes: 7700 emergency, 7600 radio failure, 7500 unlawful interference; squawk as assigned and confirm mode C altitude.

Radio failure IFR: continue per last clearance or filed route, maintain last assigned altitude for the specified period, then follow published lost-communication procedure.