BDCA CPL Knowledge Exam flashcards

39 cards. Read the term and the definition here. The deck at the top of this page is optional.

VMC minimum visibility Class D

At and above 3 050 m AMSL, 8 km flight visibility with 1 500 m horizontal and 300 m vertical cloud clearance; below 900 m AMSL, 5 km visibility, clear of cloud and surface in sight.

Right-of-way converging aircraft

When two aircraft converge at the same level, the one with the other on its right gives way; both avoid passing over, under or ahead of the other.

Squawk 7600

The transponder code selected to indicate radio communication failure; 7500 indicates unlawful interference and 7700 indicates a general emergency.

Special VFR minima

A clearance allowing flight in a control zone below VMC requires ground visibility of at least 1 500 m and a ceiling of at least 180 m, remaining clear of cloud.

Four-stroke engine cycle

Induction draws the fuel-air mixture, compression raises its pressure, combustion delivers power after ignition, and exhaust expels the gases over two crankshaft revolutions.

Carburettor icing risk range

Most likely with ambient temperatures between about -7 °C and +21 °C and high relative humidity; applying carburettor heat may initially reduce power as ice melts.

Blocked static port effects

The airspeed indicator over-reads in a climb and under-reads in a descent, the altimeter remains fixed at the blockage altitude, and the vertical speed indicator reads zero.

Load factor in level turn

Equals one divided by the cosine of the bank angle; at 60 degrees of bank the load factor is 2 and the stall speed increases by about 41 percent.

Density altitude

The pressure altitude corrected for temperature and humidity; higher density altitude reduces engine power, thrust, lift and climb rate and lengthens take-off distance.

Stall speed with load factor

Stall speed increases with the square root of load factor, so doubling the load factor raises the stall speed by a factor of about 1.41.

Centre of gravity aft limit

A centre of gravity behind the aft limit reduces static stability and control feel, can cause pitch instability and makes stall recovery more difficult.

Crosswind component formula

Crosswind equals wind speed multiplied by the sine of the angle between wind direction and runway centreline; headwind uses the cosine of the same angle.

Time of useful consciousness

At 25 000 ft about 3 to 5 minutes; at 35 000 ft about 30 to 60 seconds; at 40 000 ft about 15 to 20 seconds.

Hyperventilation treatment

Slow the breathing rate and, if symptoms persist, treat as hypoxia; hyperventilation lowers carbon dioxide and causes dizziness, tingling and visual disturbance.

Night vision rods

Rods provide dim-light vision, are insensitive to colour and detail, are concentrated in the peripheral retina and take about 30 minutes to dark adapt.

Carbon monoxide hazard

An odourless gas from engine exhaust or heater leaks that binds haemoglobin far more readily than oxygen, causing headache, drowsiness and impaired judgement.

QNH versus QFE

QNH set on the subscale makes the altimeter indicate elevation above mean sea level; QFE makes it indicate height above the aerodrome reference point.

High-to-low pressure error

Flying from high to low pressure without resetting the altimeter makes the aircraft lower than indicated, about 27 ft per hectopascal near sea level.

Cumulonimbus avoidance distance

Avoid by at least 20 km laterally, and do not attempt to overfly; hazards include severe turbulence, hail, icing, lightning, microbursts and wind shear.

Radiation fog formation

Requires clear skies, light wind, high relative humidity and cooling overnight; it usually forms near dawn and dissipates after sunrise as the surface warms.

Track versus heading

Track is the intended path over the ground; heading is the direction the aircraft nose points; drift is the angle between them caused by wind.

One in sixty rule

A track error of one degree over a distance of 60 nautical miles displaces the aircraft one nautical mile from the intended track.

Magnetic variation and deviation

Variation is the angle between true and magnetic north at a location; deviation is the error caused by the aircraft's own magnetic fields at the compass.

Great circle properties

The shortest path between two points on a sphere; its track changes continuously except along the equator or a meridian, where the track stays constant.

Wake turbulence avoidance

Take off before the preceding aircraft's rotation point and land after its touchdown point; wake is strongest behind heavy, slow, clean aircraft.

Aviate navigate communicate

The priority order during an emergency: first maintain control of the aircraft, then navigate, and only then communicate with air traffic control.

Engine failure after take-off

Maintain directional control, pitch for best glide speed, and land ahead if height is insufficient; do not attempt a turn back below safe height.

Ditching technique

Approach into wind at minimum safe speed, parallel to the swell, and touch down on the up-slope of a wave with the landing gear retracted.

Induced drag relationship

Induced drag equals the square of the lift coefficient divided by pi times aspect ratio, so it decreases with speed and increases with load factor.

Critical angle of attack

The angle at which the wing stalls; it is fixed for a given aerofoil and is reached regardless of speed, mass or aircraft attitude.

Dihedral effect

A sideslip toward one wing increases that wing's angle of attack, creating a rolling moment away from the sideslip and providing lateral stability.

Manoeuvring speed VA

The speed above which full deflection of a single control surface may exceed the limit load factor; it decreases with lower aircraft mass.

MAYDAY and PAN PAN

MAYDAY signals distress and imminent danger requiring immediate assistance; PAN PAN signals urgency concerning safety but no immediate danger of loss of life.

VHF airband characteristics

Civil VHF communications use amplitude modulation between 118.000 and 136.975 MHz with 8.33 kHz or 25 kHz channel spacing and generally line-of-sight range.

Emergency frequency 121.5 MHz

The international aeronautical emergency frequency used for distress and urgency calls; the emergency locator transmitter also transmits on 121.5 and 406 MHz.

VOR CDI indication

The course deviation indicator shows the selected radial; the TO flag means flying the selected course leads to the station, FROM means it leads away.

ILS glideslope

Normally set at 3 degrees, giving about 300 ft of height per nautical mile from the threshold; a one-degree deviation at 10 NM is about 1 000 ft.

GPS satellite requirement

At least four satellites are needed for a three-dimensional position fix, and five are needed for receiver autonomous integrity monitoring of the solution.

ADF night effect

At night, skywave propagation from distant stations interferes with the ground wave, causing bearing errors; the effect is greatest near dawn and dusk.