BDCA CPL Knowledge Exam cheat sheet

ICAO Annex 2 (Rules of the Air) applies over the high seas and, unless otherwise notified, over all contracting states; national AIP differences take precedence in national airspace.

VMC minima in Class C airspace above 3 050 m (10 000 ft) AMSL: 8 km flight visibility, 1 500 m horizontal and 300 m (1 000 ft) vertical distance from cloud.

VMC minima in Class D/E airspace at and above 3 050 m AMSL: 8 km visibility, 1 500 m horizontal and 300 m vertical cloud clearance; below 900 m AMSL in Class E: 5 km visibility, clear of cloud, surface in sight.

Special VFR clearance requires ground visibility of at least 1 500 m and a ceiling of at least 180 m (600 ft); the pilot must remain clear of cloud and keep the surface in sight.

Aircraft on converging courses: the aircraft with the other on its right gives way; head-on both turn right; overtaking aircraft keeps clear and passes to the right.

An aircraft on final approach or landing has right of way over all other aircraft; an aircraft landing or on the ground gives way to one in flight.

Emergency frequency is 121.5 MHz; unlawful interference squawk is 7500, radio failure 7600, general emergency 7700.

A controlled flight must not enter a control zone without an ATC clearance; position reports are required at compulsory reporting points and when instructed.

Aircraft must carry documents including certificate of registration, certificate of airworthiness, crew licences and, where required, the journey log and radio licence.

Four-stroke cycle order: induction, compression, combustion (power), exhaust; two crankshaft revolutions complete one full cycle in a four-stroke engine.

Detonation is uncontrolled explosive combustion producing high cylinder pressures and temperatures; pre-ignition is ignition before the spark, often caused by a hot spot.

A mixture that is too lean raises cylinder head temperature; full rich mixture is used for take-off and to cool the engine at high power.

Carburettor icing is most likely at ambient temperatures between -7 °C and +21 °C with high relative humidity; use carburettor heat to melt ice, expecting an initial power loss.

The pitot-static system: pitot supplies dynamic pressure only; static ports supply static pressure to the ASI, altimeter and VSI.

Blocked static port causes the ASI to over-read in climb and under-read in descent; the altimeter freezes at the altitude where the blockage occurred.

The magnetic compass turns towards the north-indicating end during acceleration in the northern hemisphere (ANDS: Accelerate North, Decelerate South) and is unreliable in turns.

Load factor n = 1/cos(bank angle) in a level turn; at 60° bank load factor is 2, raising stall speed by a factor of 1.41.

Density altitude rises with altitude, temperature and humidity; it degrades engine power, propeller thrust, lift and climb performance.

Take-off and landing distances increase with mass, altitude and temperature; headwind decreases and tailwind increases ground roll.

Stall speed varies with the square root of load factor: Vs(new) = Vs × √n; at 2 g the stall speed rises by 41 %.

Rate of climb = (excess power)/weight; angle of climb = (excess thrust)/weight, so best angle occurs at lower speed than best rate.

Centre of gravity forward of the limit increases stability but lengthens take-off run and reduces climb performance; aft of the limit reduces static stability and can cause pitch instability.

Endurance is maximum at the speed for minimum power required (approximately 1.32 × Vmd), range is maximum at the speed for minimum drag.

Fuel planning: taxi, trip, contingency (typically 5 % of trip), alternate and final reserve (30 minutes at holding speed for piston aircraft) must be included.

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

Hypoxia symptoms: euphoria, impaired judgement, cyanosis, headache and loss of coordination; time of useful consciousness at 25 000 ft is about 3 to 5 minutes.

Hyperventilation produces dizziness and tingling from low CO2; treatment is to slow the breathing rate, not to increase it.

Spatial disorientation arises when vestibular and visual cues conflict; trust the flight instruments rather than body sensations in IMC.

Night vision relies on rods, which are sensitive to dim light, poor at detail and colour, and are destroyed by bright white light; dark adaptation takes about 30 minutes.

Carbon monoxide is odourless and binds haemoglobin about 200-250 times more readily than oxygen; smoking and heater leaks raise the risk.

Fatigue degrades reaction time, vigilance and decision-making; circadian low points occur around 03:00-05:00 and 15:00-17:00 local time.

Decompression sickness results from dissolved nitrogen forming bubbles on rapid pressure loss; avoid flying 12-24 hours after diving depending on dive profile.

The 'IMSAFE' checklist covers Illness, Medication, Stress, Alcohol, Fatigue and Emotion as fitness-to-fly factors.

Standard atmosphere: sea-level pressure 1013.25 hPa, temperature 15 °C, lapse rate 1.98 °C per 1 000 ft up to 36 090 ft (tropopause).

Altimeter set to QNH gives elevation; QFE gives height above the aerodrome reference point; QNE (1013.25 hPa) gives flight level.

1 hPa pressure change corresponds to about 27 ft near sea level; flying from high to low pressure without resetting the altimeter causes the aircraft to be lower than indicated.

Cumulonimbus hazards include severe turbulence, icing, hail, lightning, microbursts and wind shear; avoid by at least 20 km (10 NM) laterally.

Icing is most likely between 0 °C and -20 °C in visible moisture; clear ice forms from large supercooled droplets, rime ice from small droplets.

Fog forms when temperature reaches dew point; radiation fog needs clear skies, light wind and high humidity, and usually dissipates after sunrise.

In the northern hemisphere wind blows anticlockwise around a low and clockwise around a high; surface friction causes wind to cross isobars at about 30° over land.

A cold front has a steep slope (about 1:50), fast movement and narrow bands of heavy showers; a warm front has a shallow slope (about 1:150) and widespread steady rain.

1 nautical mile = 1 852 m; 1 knot = 1 NM/h; 1 minute of latitude = 1 NM.

Track is the intended path over the ground; heading is where the aircraft nose points; drift is the angle between them.

Wind correction angle = arcsin((wind speed × sin(wind angle))/TAS); headwind/tailwind component = wind speed × cos(wind angle).

True airspeed ≈ IAS × (1 + 0.02 × altitude in thousands of feet) for a rough density correction at low altitude.

Magnetic variation east is subtracted from true to obtain magnetic; deviation is the compass error from the aircraft's own magnetic field.

Great circle distance uses the spherical law of cosines; the great circle track changes continuously except along the equator or a meridian.

1 in 60 rule: a 1° track error over 60 NM produces a 1 NM off-track displacement.

The magnetic compass is unreliable during turns and in acceleration; use the directional gyro or heading indicator for steady heading references.

Wake turbulence is greatest behind heavy, slow, clean aircraft; take off before the preceding aircraft's rotation point and land after its touchdown point to avoid it.

Wind shear on approach is countered by go-around; do not attempt to chase the glideslope with large power or pitch changes.

An engine failure after take-off at low altitude: maintain directional control, pitch for best glide or VY, and land ahead if insufficient height to turn back.

The emergency checklist order is generally: fly the aircraft, analyse the problem, then act; aviate, navigate, communicate.

Before take-off, brief the departure, emergency actions, rejected take-off decision and the actions after engine failure.

A clearance must be read back in full when it contains a route, altitude, heading or frequency instruction; read back the runway and hold-short instruction at all times.

Landing on a contaminated runway increases stopping distance; use maximum reverse and braking and expect reduced friction coefficient.

Ditching: approach into wind with minimum safe speed, parallel to swell, and touch down on the up-slope of a wave if possible.

Lift L = ½ρV²SCL; induced drag Di = ½ρV²S × CL²/(πAe), so induced drag falls with increasing speed while parasite drag rises.

Total drag is minimum at the speed where induced drag equals parasite drag; this is Vmd, the speed for maximum glide ratio.

Critical angle of attack is fixed for a given aerofoil; the stall occurs at that angle regardless of speed, mass or attitude.

The centre of pressure moves forward as angle of attack increases up to the stall, producing an unstable pitching tendency in a cambered wing.

Dihedral provides lateral stability by creating a sideslip-induced rolling moment toward the low wing.

Aspect ratio A = span²/area; high aspect ratio reduces induced drag, which is why gliders have long, narrow wings.

Flaps increase lift coefficient and drag; they also increase the pitching moment and reduce the stalling angle of attack.

Load factor increases in turns and pull-ups; the manoeuvring speed VA is the speed above which full deflection of one control may exceed the limit load.

VHF airband uses amplitude modulation between 118.000 and 136.975 MHz with 8.33 kHz or 25 kHz channel spacing.

The 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 are transmitted digit by digit, except whole hundreds and thousands, which may be spoken as 'hundred' and 'thousand'.

Distress call is MAYDAY, urgency call is PAN PAN; both are repeated three times when time permits.

Read back all runway, hold-short, altitude, heading and frequency instructions; read back the full route clearance.

If a transmission is blocked, the phrase 'BLOCKED' is used; 'SAY AGAIN' requests repetition and 'STANDBY' means wait for a call.

Emergency transmitter frequency is 121.5 MHz; the emergency locator transmitter transmits on 121.5 and 406 MHz.

Radio failure in VMC: continue under VMC, land at the nearest suitable aerodrome and report arrival; in IMC follow the published lost-communication procedure.

NDB transmits on 190-535 kHz and provides bearing only; ADF errors include night effect, coastal refraction, mountain effect and quadrantal error.

VOR operates on 108.0-117.95 MHz; the CDI shows the selected radial, and the TO/FROM flag indicates whether the radial leads to or from the station.

DME measures slant range in nautical miles; error is greatest directly overhead, where indicated range exceeds the actual ground distance.

ILS localiser operates on 108.10-111.95 MHz (odd tenths) and gives lateral guidance; the glideslope is normally 3° and is on UHF 329.15-335.0 MHz.

Marker beacons: outer marker 400 Hz blue, middle marker 1 300 Hz amber, inner marker 3 000 Hz white.

GPS needs at least four satellites for a three-dimensional fix and five for RAIM-based integrity monitoring.

Transponder modes: Mode A gives identity, Mode C adds pressure altitude, Mode S supports selective addressing and data link.

A 3° glideslope gives about 300 ft of height per nautical mile from the threshold; a 1° deviation at 10 NM is about 1 000 ft.