CARC PPL Theory cheat sheet

Aircraft nationality marks: registration prefix (e.g., G- for UK, N for USA, D- for Germany) must be displayed on the fuselage; the flag of the state of registry may replace the prefix for some states.

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

VFR minima (ICAO, outside controlled airspace): flight visibility 5 km, 1500 m horizontally and 300 m (1000 ft) vertically from cloud; at or below 900 m (3000 ft) AMSL: 5 km visibility, clear of cloud and in sight of surface.

Special VFR: clearance to operate within a control zone in IMC; pilot must remain clear of cloud and in sight of surface; visibility minima typically 1500 m (varies by state).

ATC clearances: read back all clearances that involve runway, altitude, heading, speed, and frequency; if a clearance is not understood, request clarification; never assume.

Position reporting: compulsory at designated reporting points; include aircraft call sign, position, time, altitude, and next position with ETA.

Wake turbulence separation: heavy behind heavy: 4 NM; medium behind heavy: 5 NM; light behind heavy: 6 NM; light behind medium: 5 NM (ICAO).

Emergency frequencies: VHF 121.5 MHz; UHF 243.0 MHz; emergency transponder code 7700; radio failure 7600; unlawful interference 7500.

Altimeter setting: QNH gives altitude above mean sea level; QFE gives height above aerodrome; QNE (1013.25 hPa) used above transition altitude for flight levels.

Four-stroke cycle: induction, compression, combustion (power), exhaust; in a horizontally opposed engine, each cylinder fires once every two crankshaft revolutions.

Magneto: self-contained ignition source; two magnetos provide redundancy; check mag drop during run-up; max drop typically 150 RPM, max difference 50 RPM.

Carburettor icing: most likely at temperatures between -5°C and +15°C with high humidity; use carb heat as preventive; apply full carb heat if icing suspected, expect RPM drop then recovery.

Constant-speed propeller: governor controls blade angle to maintain selected RPM; oil pressure drives blade angle; loss of oil pressure causes propeller to go to fine pitch (high RPM) in some designs.

Electrical system: battery provides power for starting and emergency; alternator/generator charges battery and powers avionics; ammeter shows charge/discharge; voltage regulator prevents overcharge.

Hydraulic system: Pascal's law - pressure applied to confined fluid is transmitted equally in all directions; used for landing gear, brakes, flaps on larger aircraft.

Pitot-static system: pitot tube provides dynamic pressure for airspeed indicator; static port provides static pressure for altimeter, VSI, and airspeed; blockage affects instruments differently.

Fuel system: gravity feed vs. pump feed; fuel selector valve; primer; mixture control; check for water and sediment during preflight; use correct grade (e.g., 100LL).

Mass and balance: maximum take-off mass (MTOM), maximum landing mass (MLM), maximum zero-fuel mass (MZFM); centre of gravity (CG) must remain within forward and aft limits throughout flight.

CG position: forward CG increases stability but reduces performance (longer take-off, higher stall speed); aft CG reduces stability and can cause unrecoverable stall/spin.

Load sheet: compute mass and CG by summing moments (mass × arm) and dividing total moment by total mass; use datum and station arms.

Take-off distance: affected by mass, altitude, temperature, wind, runway slope, and surface; use performance charts; increase distance by 10% for each 1000 ft elevation (rule of thumb) and 10% for each 10°C above standard.

Climb performance: rate of climb decreases with altitude; service ceiling where climb rate falls below 100 ft/min; absolute ceiling where climb rate is zero.

Fuel planning: include taxi, trip, contingency (typically 5% of trip fuel), alternate, final reserve (30 min for VFR, 45 min for IFR), and extra fuel.

Flight plan: filed with ATC; includes aircraft identification, type, wake turbulence category, equipment, departure, route, destination, alternate, cruising speed and level, EET, and endurance.

Monitoring: in-flight, compare actual fuel consumption and groundspeed with flight plan; update ETA; if deviations exceed limits, inform ATC.

Hypoxia: symptoms include euphoria, impaired judgement, headache, dizziness; time of useful consciousness at 25,000 ft is 3-5 minutes; at 40,000 ft 15-20 seconds; use supplemental oxygen above 10,000 ft (FAA) or as required by state.

Spatial disorientation: caused by conflicting visual and vestibular inputs; rely on instruments; common illusions: somatogravic (false climb/descent), somatogyral (false turn), Coriolis.

Decompression sickness: nitrogen bubbles in blood/tissues; symptoms joint pain, chest pain, neurological; avoid flying after diving (minimum 24 hours after diving without symptoms).

Fatigue: acute vs. chronic; impairs reaction time, attention, and decision-making; controlled rest on flight deck can mitigate; adhere to flight time limitations.

Vision: foveal (central) vision for detail, peripheral for motion detection; night vision uses rods, poor colour discrimination; avoid bright light before night flight; use off-centre viewing.

Stress: fight-or-flight response; can lead to narrowed attention and impaired judgement; use stress management techniques (breathing, systematic scan).

Human error: slips (correct intention, wrong execution), lapses (forgotten actions), mistakes (wrong intention), violations; use checklists and cross-monitoring to trap errors.

Crew resource management (CRM): communication, leadership, teamwork, decision-making, situational awareness; assertiveness and conflict resolution.

ISA: sea level temperature 15°C, pressure 1013.25 hPa, temperature lapse rate 1.98°C per 1000 ft (2°C per 1000 ft approx) up to 36,090 ft.

Pressure systems: low pressure (cyclone) - air rises, clouds and precipitation; high pressure (anticyclone) - air subsides, clear skies; wind flows clockwise around high in Northern Hemisphere, counterclockwise around low.

Cloud types: cumulus (convective, unstable), stratus (stable, layered), cirrus (high, ice), cumulonimbus (thunderstorms, severe turbulence, icing, hail).

Icing: rime ice (rough, from supercooled droplets), clear ice (glaze, large droplets), mixed; most severe in cumuliform clouds at temperatures between 0°C and -15°C; use anti-icing/de-icing equipment.

Thunderstorms: three stages - cumulus, mature, dissipating; hazards: lightning, hail, turbulence, downbursts, microbursts, icing; avoid by at least 20 NM.

Wind shear: sudden change in wind speed/direction; can cause sudden airspeed loss or gain; on approach, go-around if unable to maintain stabilised approach.

Visibility: fog forms when temperature reaches dew point (cooling or adding moisture); radiation fog (clear night, light wind), advection fog (warm moist air over cold surface).

METAR/TAF: METAR is routine weather report; TAF is aerodrome forecast; decode: wind direction/speed/gusts, visibility, weather, cloud, temperature/dew point, QNH, trend.

Great circle: shortest path between two points on a sphere; track changes continuously; rhumb line: constant track, longer than great circle (except at equator or meridians).

Mercator projection: rhumb lines are straight; scale increases with latitude; used for navigation charts; great circles are curved (except equator and meridians).

Heading, track, and drift: heading is direction aircraft points; track is actual path over ground; drift = track - heading; wind correction angle (WCA) = heading - desired track.

Triangle of velocities: true airspeed (TAS) and true heading (TH) combined with wind velocity (W/V) give groundspeed (GS) and true track (TRK); use flight computer or E6B.

VOR: very high frequency omnidirectional range; provides magnetic bearing (radial) from station; CDI shows deviation; TO/FROM indicator; line of ambiguity perpendicular to radial.

ILS: instrument landing system; localizer provides lateral guidance (108-112 MHz), glideslope provides vertical guidance (329.15-335 MHz); markers at outer, middle, inner; decision altitude/height.

GPS: satellite navigation; RAIM (receiver autonomous integrity monitoring) for integrity; WAAS/SBAS for augmentation; accuracy typically 3-5 m.

Transponder: Mode A (identification), Mode C (altitude), Mode S (data link); squawk codes assigned by ATC; 7700 emergency, 7600 radio failure, 7500 hijack.

Pre-flight actions: check weather, NOTAMs, aircraft documents (certificate of airworthiness, registration, insurance), mass and balance, fuel, and perform walk-around inspection.

Engine start: follow checklist; ensure area clear; use primer as required; monitor oil pressure; if no oil pressure within 30 seconds, shut down.

Taxi: use appropriate taxi speed; differential braking or nosewheel steering; hold short of runways; obtain clearance before entering runway.

Take-off: line up, set power, check engine instruments, rotate at Vr, climb at Vx (best angle) or Vy (best rate); after take-off checks: gear up, flaps up, power set.

Approach and landing: obtain ATIS, approach clearance; configure aircraft (flaps, gear); stabilised approach by 500 ft (IMC) or 300 ft (VMC); go-around if not stabilised.

Emergency procedures: engine failure after take-off - establish glide, select landing site, attempt restart, MAYDAY call; engine fire - shut off fuel, use extinguisher, land ASAP.

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

Post-flight: park, shut down, secure aircraft, refuel if required, report defects, complete technical log.

Lift: generated by pressure difference due to Bernoulli and Newton; L = ½ ρ V² S CL; CL increases with angle of attack up to critical angle (stall).

Stall: occurs when critical angle of attack exceeded; speed increases with weight, altitude, load factor; stall speed increases with square root of load factor (Vs1g × √n).

Drag: parasite drag (form, skin friction, interference) increases with V²; induced drag decreases with V²; total drag minimum at best glide speed (L/D max).

Stability: static stability (tendency to return), dynamic stability (oscillation damping); longitudinal stability provided by horizontal stabiliser; CG forward increases stability.

Control: elevator controls pitch, ailerons roll, rudder yaw; adverse yaw countered by rudder; differential ailerons reduce adverse yaw.

Load factor: ratio of lift to weight; increases in turns (n = 1/cos bank angle); limit load factor for normal category 3.8g, utility 4.4g.

Ground effect: reduced induced drag and increased lift when within one wingspan of ground; can cause float during landing.

Mach effects: critical Mach number, shock waves, tuck-under; swept wings delay onset; use Mach trim.

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.

Standard phraseology: "roger" (received), "wilco" (will comply), "affirm" (yes), "negative" (no), "say again" (repeat), "standby" (wait), "unable" (cannot comply).

Call sign: use aircraft type and last three letters of registration (e.g., Cessna G-ABCD as "Cessna Alpha Bravo Charlie Delta"); after initial contact, may abbreviate to last two letters.

Departure call: "[Aerodrome] Tower, [Call sign], [Position], [Altitude], [Intentions]" e.g., "Elstree Tower, Cessna Alpha Bravo Charlie, holding point runway 26, ready for departure, VFR to Wycombe."

Position report: "[Call sign], [Position], [Time], [Altitude], [Next position and ETA]" e.g., "G-ABCD, overhead Bovingdon, 10, 2500 feet, next Denham, ETA 12."

Emergency: MAYDAY (distress) repeated three times; PAN-PAN (urgency) repeated three times; include call sign, nature of emergency, position, altitude, intentions.

Read-back: read back clearances involving runway, altitude, heading, speed, frequency; e.g., "Cleared to land runway 26, G-ABCD".

Frequency: use correct frequency; monitor 121.5 MHz for emergency; if lost comms, squawk 7600 and follow procedures.