IDAC Private Pilot Airplane (PPA) flashcards

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

Class G airspace

Uncontrolled airspace in which no ATC clearance is required for VFR flight; separation is not provided and pilots are responsible for collision avoidance.

Semi-circular rule

IFR cruising levels: tracks 000–179° magnetic use odd thousands, tracks 180–359° use even thousands, applied above the transition altitude.

Right-of-way converging

When two aircraft of the same category converge, the aircraft on the right has right-of-way; the other must give way.

Navigation lights requirement

Aircraft must display navigation lights between sunset and sunrise or in reduced visibility; anti-collision lights are used day and night unless they create a hazard.

Four-stroke cycle

Intake, compression, power and exhaust strokes; each cylinder produces one power stroke per two crankshaft revolutions.

Carburettor icing range

Most likely at ambient temperatures between −10 °C and +15 °C with high humidity; carburettor heat raises mixture temperature and causes a power drop.

Detonation

Uncontrolled explosive combustion after normal ignition, causing high cylinder head temperature and possible engine damage; often linked to over-lean mixture.

Altimeter setting QNH

Subscale set to QNH makes the altimeter read altitude above mean sea level; QFE reads height above the aerodrome, QNE reads flight level.

Load factor in turn

Load factor n = 1/cos(bank); at 60° bank it is 2 g, and stall speed rises with the square root of n.

Density altitude formula

Pressure altitude plus 120 ft per °C above ISA temperature; higher density altitude increases take-off distance and reduces climb performance.

CG shift rule

Adding mass shifts the centre of gravity toward the added station; removing mass shifts it away from that station.

Final reserve fuel

Fuel required after the alternate: typically 30 minutes at holding speed for VFR and 45 minutes for IFR flight.

Best rate of climb VY

Speed giving maximum altitude gain per unit time; best angle VX gives maximum altitude gain per unit distance.

Time of useful consciousness

At FL 250 roughly 3–5 minutes; at FL 350 about 30–60 seconds for an unacclimatised person.

Somatogravic illusion

Acceleration feels like a climb and deceleration feels like a descent; it can cause spatial disorientation during take-off or go-around.

Hyperventilation

Rapid breathing causing dizziness, tingling and visual disturbance; treatment is to slow the breathing rate or rebreathe into a bag.

Carbon monoxide poisoning

Odourless gas binding haemoglobin about 200–250 times more strongly than oxygen; causes headache, drowsiness and cherry-red skin.

ISA lapse rate

Standard atmosphere: sea level 15 °C and 1013.25 hPa, temperature decreasing about 2 °C per 1000 ft up to 36 090 ft, then constant.

Clear ice

Glaze ice formed by large supercooled droplets at 0 to −10 °C; it is the most dangerous icing type because it spreads and disrupts airflow.

Radiation fog

Forms on clear, calm nights with high humidity as the ground cools; it dissipates after sunrise when the surface warms.

Thunderstorm stages

Cumulus stage with updrafts, mature stage with both updrafts and downdrafts plus rain and hail, and dissipating stage dominated by downdrafts.

Great circle

Shortest distance between two points on the Earth's surface; a rhumb line crosses meridians at a constant angle and is longer except on the equator or a meridian.

Latitude and longitude distance

One minute of latitude equals 1 NM; one degree of longitude equals 60 NM multiplied by the cosine of the latitude.

Magnetic variation

East variation is subtracted from true heading to get magnetic heading; west variation is added; deviation is the compass error caused by aircraft magnetism.

VOR radial

Magnetic bearing from the station; the CDI centres when the OBS is set to the radial to or from the station, with reverse sensing if set to the reciprocal.

Glideslope descent rate

A 3° ILS glideslope descends about 300 ft per nautical mile; glideslope frequencies are 329.15–335 MHz.

MAYDAY call

Distress call made three times with station called, callsign, nature of distress and position; PAN PAN is the urgency call.

Wake turbulence avoidance

Vortices are strongest when the aircraft is heavy, clean and slow; stay above the flight path and allow at least 3 minutes behind a heavy aircraft.

Emergency squawk codes

7500 unlawful interference, 7600 radio failure, 7700 general emergency; set only when instructed or in an emergency.

Lift formula

Lift = ½ ρ V² S CL; doubling speed quadruples lift at a given angle of attack.

Critical angle of attack

The angle at which the aerofoil stalls, about 15–18° for most aerofoils; the stall occurs at this angle regardless of speed, mass or attitude.

Adverse yaw

The downgoing aileron produces more induced drag, yawing the nose away from the turn; coordinated rudder prevents it.

Read-back requirement

Clearances, hold-short instructions and frequency changes must be read back, including callsign, clearance limit, route and altitude.