BDCA PPL Knowledge Exam cheat sheet

VFR meteorological minima (EASA airspace classes, below 10 000 ft AMSL): flight visibility 5 km and 1500 m horizontal / 300 m (1000 ft) vertical distance from cloud; at or above 10 000 ft: 8 km visibility and 1500 m horizontal / 600 m (1000 ft) vertical separation.

Class C airspace: ATC clearance required for all flights; IFR separated from IFR and from VFR, VFR separated from IFR and given traffic information about other VFR. Class D: clearance required, IFR separated from IFR only, traffic information to VFR.

Class E: IFR requires clearance, VFR does not; IFR separated from IFR, VFR receives traffic information. Class F/G: no ATC clearance, IFR and VFR receive traffic information as far as practicable (G: none).

Semi-circular (quadrantal) rule for IFR levels above 3000 ft AGL: tracks 000-179 magnetic use even flight levels, 180-359 use odd flight levels; altitude in feet = flight level x 100 at standard pressure 1013.2 hPa.

Transition altitude: the altitude at or below which the vertical position is expressed in altitudes (QNH); transition level is the lowest flight level available above the transition altitude, set on QNE (1013.2 hPa).

Aerodrome traffic circuit: join downwind at circuit height, keep the aerodrome and runway in sight, and give way to traffic on final; landing aircraft on final have right of way over aircraft on the ground or in the circuit.

Right-of-way rules: 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 emergency or landing has priority.

Aircraft must not fly closer than 500 ft to any person, vessel, vehicle or structure, except with the permission of the competent authority or when landing/taking off; over congested areas maintain a height permitting a safe forced landing.

Documents carried on board (EASA): certificate of registration, airworthiness certificate, noise certificate (if applicable), crew licences, aircraft radio licence, journey log, and the operations manual when required; the pilot-in-command is responsible for their validity.

Four-stroke cycle: induction, compression, power (combustion), exhaust; in a four-cylinder engine the crankshaft turns 720 degrees per complete cycle, giving two revolutions per power stroke per cylinder.

Mixture ratio: stoichiometric is about 15:1 air to fuel by mass; best power is slightly rich (about 12:1), best economy is lean (about 16:1); excessively lean mixture raises cylinder head temperature and can cause detonation.

Detonation: explosive, uncontrolled combustion producing high peak pressures and temperatures, audible knocking; causes include low octane fuel, too lean mixture, high manifold pressure at low RPM, and high inlet air temperature. Pre-ignition is ignition before the spark.

Magneto: self-contained engine-driven ignition generator; two magnetos give redundancy, and the drop during the magneto check (max about 175 RPM, max difference 50 RPM) shows both circuits are working.

Constant-speed propeller: the governor regulates oil flow to the propeller hub to hold selected RPM; increasing RPM increases drag and reduces blade angle; a windmilling propeller can be feathered to reduce drag.

Electrical system: battery supplies power for starting and is the emergency source; the alternator charges the battery and supplies the bus; ammeter/loadmeter indicates current flow, and the master switch connects the battery and alternator contactors.

Pitot-static system: pitot tube feeds the airspeed indicator only; static port feeds the altimeter, vertical speed indicator and airspeed indicator; a blocked static port causes the ASI to over-read in a climb and under-read in a descent.

Hydraulic and pneumatic systems: hydraulic fluid transmits force, pressure relief valves protect the system, and accumulators dampen pressure surges; pneumatic systems (engine-driven vacuum pumps) drive gyroscopic instruments.

Fuel system: gravity feed or pump feed, selector valve, strainer/filter, and vent to atmosphere; water and sediment settle at the lowest point and are removed during the pre-flight drain; fuel quantity is measured in litres or US gallons (1 US gal = 3.785 L).

Mass and balance: total mass = empty mass + crew + passengers + baggage + fuel; the centre of gravity must remain within the forward and aft limits for the whole flight, including fuel burn-off.

Moment = mass x arm; centre of gravity position = total moment / total mass; adding mass forward of the CG moves the CG forward, adding mass aft moves it aft.

Forward CG limit: increases stability and stick force, lengthens take-off run and reduces climb performance and range; aft CG limit: reduces stability and can make the aircraft uncontrollable in the stall.

Density altitude = pressure altitude + 120 x (OAT in degrees C minus ISA temperature for that level); high density altitude reduces engine power, propeller thrust and lift, increasing take-off and landing distances.

Take-off and landing distance factors: mass, density altitude, wind (headwind decreases, tailwind increases distance), runway slope, surface condition (grass, wet, contaminated) and flap setting.

Climb performance: rate of climb = excess power / weight; best rate of climb speed (Vy) gives maximum height gain per unit time, best angle of climb speed (Vx) gives maximum height per unit horizontal distance.

Fuel planning: trip fuel + contingency (typically 5 percent of trip fuel) + alternate fuel + final reserve (30 minutes holding at 1500 ft for VFR) + taxi fuel; check fuel against endurance = usable fuel / consumption.

Flight plan: ICAO format includes aircraft identification, type, wake turbulence category, departure and destination, route, level, speed, endurance, persons on board and emergency radio; filing is required for cross-border flights and IFR.

Hypoxia: insufficient oxygen to tissues; symptoms include euphoria, impaired judgement, cyanosis and headache; time of useful consciousness at 25 000 ft is about 3-5 minutes, at 35 000 ft about 30-60 seconds.

Hyperventilation: excessive breathing rate lowers carbon dioxide, causing dizziness, tingling and cramps; treat by slowing the breathing rate and, if hypoxia is suspected, use 100 percent oxygen.

Spatial disorientation: the vestibular system cannot distinguish sustained turns or accelerations without visual reference; rely on instruments, especially during inadvertent entry into cloud.

The leans and somatogravic illusion: a sudden acceleration is felt as a climb, and a sustained coordinated turn may not be perceived; illusions are strongest in low-visibility conditions.

Vision: foveal (cone) vision gives colour and detail; peripheral (rod) vision is better at night and detects motion; dark adaptation takes 30 minutes, and smoking and high altitude slow it.

Stress and fatigue: moderate stress improves performance, but excessive stress causes narrowing of attention and errors; fatigue impairs reaction time and decision-making, and rest is the only effective remedy.

Crew resource management: communication, leadership, situational awareness and decision-making; assertiveness is required from the less experienced pilot, and the sterile flight deck rule applies below 10 000 ft.

Decompression and oxygen: at cabin altitude above 10 000 ft supplemental oxygen is needed; a rapid decompression requires immediate use of oxygen masks and an emergency descent to below 10 000 ft.

ISA: sea level temperature 15 degrees C, pressure 1013.25 hPa, lapse rate 1.98 degrees C per 1000 ft up to 36 090 ft (tropopause, about -56.5 degrees C).

Pressure: 1 hPa = 0.03 inHg approximately; altimeter set to QNH reads elevation above mean sea level, QFE reads height above the aerodrome reference point, and QNE (1013.2) gives flight levels.

Cloud types: cumulus (convective, unstable air), stratus (stable, layered), cirrus (high, ice), cumulonimbus (thunderstorm, severe icing, turbulence, hail); cloud base in feet = (temperature - dewpoint) x 400.

Stability: stable air gives layered cloud, steady precipitation and good visibility outside cloud; unstable air gives showery precipitation, cumuliform cloud, turbulence and good visibility between showers.

Icing: clear (rime) ice forms in stratiform cloud at 0 to -10 degrees C, and rime ice in cumuliform cloud at -10 to -20 degrees C; freezing rain is the most dangerous; carburettor icing can occur at temperatures between -7 and +21 degrees C with high humidity.

Thunderstorms: require moisture, instability and a lifting trigger; stages are cumulus, mature and dissipating; avoid by at least 10 nm laterally, and do not fly under the anvil or into hail shafts.

Fronts: cold front - steep slope, narrow band, heavy showers, rapid passage and a wind veer; warm front - shallow slope, wide precipitation belt, gradual passage and poor visibility; occluded front combines both.

Wind: veers with height in the northern hemisphere in the friction layer; surface wind is backed relative to gradient wind; wind shear and microbursts are most dangerous close to the ground on approach.

Great circle: the shortest path between two points on the Earth's surface; the rhumb line is a constant-track line on the Mercator chart and is longer except along the equator or a meridian.

Conversions: 1 nautical mile = 1 minute of latitude = 1852 m; 1 knot = 1 nm/h; 1 degree of longitude at the equator is 60 nm, decreasing with the cosine of latitude.

Magnetic variation: the angle between true and magnetic north, east or west; magnetic heading = true heading minus easterly variation (add westerly); deviation is the error of the compass itself.

Triangle of velocities: true heading and true airspeed combined with wind velocity give track and groundspeed; drift is the angle between heading and track, and wind correction angle is applied into the wind.

VOR: provides magnetic bearing from the station (radial); CDI centred with a FROM indication means the aircraft is on the selected radial; TO/FROM flag indicates whether the selected course leads to or from the station.

NDB/ADF: relative bearing is the angle between the aircraft heading and the direction to the station; magnetic bearing = heading + relative bearing; the ADF needle points to the station.

ILS: localizer gives lateral guidance (108-112 MHz), glidepath gives vertical guidance (typically 3 degrees, about 300 ft per nm); decision height is referenced to the radio altimeter.

GPS: position from satellite ranging; RAIM monitors integrity; a minimum of 4 satellites is needed for a 3D fix, and 5 for RAIM fault detection; the receiver must be approved for the intended operation.

Pre-flight: check documents, mass and balance, weather, NOTAMs, fuel and aircraft serviceability; complete the walk-around and confirm the fuel drains are clear of water and sediment.

Engine start and run-up: follow the checklist, check magnetos (max drop 175 RPM, max difference 50 RPM), carburettor heat, idle and oil pressure; abort if limits are exceeded.

Take-off: use the correct flap setting, check the runway and wind, apply full power, check engine instruments, rotate at Vr and climb at Vx or Vy; abort if the engine fails before V1 (multi-engine) or before lift-off.

Emergency: engine failure after take-off - lower the nose to maintain speed, select a landing area ahead, do not turn back below 500 ft; forced landing - glide at best glide speed, restart checks, mayday and passenger briefing.

Fire: on the ground, stop the engine, evacuate and use the extinguisher; in flight, close the fuel and mixture, shut off the electrical supply and use the extinguisher, then land as soon as possible.

Radio failure VFR: continue in VMC, land at the nearest suitable aerodrome and report; squawk 7600; if in controlled airspace follow the published lost-communication procedure.

Wake turbulence: generated by wingtip vortices, strongest when heavy, clean and slow; take off before and land after a heavy aircraft, and stay above its flight path.

Checklists and sterile cockpit: use written checklists for normal and emergency procedures; no non-essential conversation below 10 000 ft or during taxi, take-off, approach and landing.

Lift = 1/2 x rho x V squared x S x CL; lift increases with the square of speed and with air density; at a given mass, the stall speed depends on the square root of the load factor.

Angle of attack: the angle between the chord line and the relative airflow; the critical angle (about 15 degrees) gives maximum lift and the stall; the stall speed rises with load factor and with forward CG.

Induced drag: caused by the generation of lift, proportional to the square of the lift coefficient and inversely proportional to speed squared; total drag is minimum at the speed where induced drag equals parasite drag (best glide speed).

Stability: positive static stability tends to return to equilibrium; longitudinal stability is provided by the horizontal tailplane, and a forward CG increases stability but increases stick force.

Load factor: n = lift / weight; a level 60-degree bank gives n = 2 and stall speed increases by the square root of 2 (about 41 percent); the V-n diagram shows the manoeuvring and gust envelope.

Control: ailerons give roll, elevator gives pitch, rudder gives yaw; adverse yaw is caused by the increased induced drag of the rising aileron wing; the rudder is used to coordinate the turn.

Turning: in a level turn, load factor n = 1 / cos(bank angle); the horizontal component of lift provides the centripetal force and the vertical component balances weight.

Stall recovery: reduce angle of attack by moving the control column forward, keep the wings level with the rudder, and add power as height is regained; a wing drop is countered with rudder, not aileron.

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 (e.g. one-two-three); flight levels as three digits (FL 095); headings as three digits; frequencies as six digits with the decimal point; altimeter setting as four digits.

Standard phraseology: "line up and wait", "cleared for take-off", "cleared to land", "roger", "wilco", "affirm", "negative", "say again", "standby", "unable", and "correction" for errors.

Read-back: mandatory for clearances, runway and hold-short instructions, altimeter settings, headings, speeds, frequencies and transponder codes; the pilot must read back and the controller must hear it.

Distress and urgency: MAYDAY (distress, three times) and PAN-PAN (urgency, three times); include station addressed, call sign, nature of problem, position, level, heading and intentions.

Emergency frequencies: 121.5 MHz (civil emergency, guarded by ATC), 243.0 MHz (military); squawk 7700 (emergency), 7600 (radio failure), 7500 (unlawful interference).

Radio technique: listen before transmitting, use the correct call sign, keep transmissions brief, and use standard phraseology; the VHF range is line-of-sight, roughly 1.23 x square root of height in feet (nm).

Clearances: an ATC clearance is not authority to deviate from regulations; if unable to comply, say "unable" and state the reason; a clearance must be read back in full before it is acted on.