ANAC Glider Pilot flashcards

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

Sailplane airworthiness certificate

Document certifying a glider meets the sailplane category standards; it must be valid and available on board, and maintenance records must be kept current for the aircraft to be legally flown.

VFR cloud distance minima

In controlled airspace at and above 3050 m AMSL, remain 1500 m horizontally and 300 m vertically from cloud with 5 km visibility; below that level, remain clear of cloud with surface in sight.

Glider right-of-way rule

A glider has priority over powered aircraft, airships, and helicopters. Between gliders, the lower aircraft has priority and the aircraft on the right has priority when converging.

Pitot blockage indication

A blocked pitot tube causes the airspeed indicator to behave like an altimeter: airspeed increases in a climb and decreases in a descent, because only static pressure changes reach the instrument.

Total-energy variometer

A variometer compensated for changes in dynamic pressure, so that pulling up or pushing over does not produce false climb or sink readings; it indicates the true rate of energy gain.

Yaw string function

A string on the canopy showing relative airflow; it streams straight back in coordinated flight and deflects toward the inside of a slip, guiding rudder correction.

Wing loading formula

Wing loading equals mass divided by wing area, expressed in kg/m². Higher wing loading raises stall and best glide speeds and improves penetration in strong winds.

Glide ratio meaning

Horizontal distance travelled divided by height lost in still air; a 40:1 ratio means 40 km of glide from 1000 m of height, reduced by headwind and sink.

Final glide height calculation

Required height equals distance times sink rate divided by ground speed, plus a safety margin of at least 300 m (1000 ft) to arrive at the airfield with height to spare.

Density altitude effect

Height in the standard atmosphere corresponding to the actual density; high temperature and altitude raise it, reducing lift and increasing takeoff run and climb time.

Hypoxia onset altitude

In unacclimatised pilots, symptoms such as euphoria and impaired judgement begin near 3000 m (10 000 ft); supplemental oxygen is required above 3800 m (12 500 ft) for flights over 30 minutes.

Hyperventilation treatment

Rapid breathing lowers blood carbon dioxide, causing dizziness and tingling; treatment is to slow the breathing rate and reassure the pilot, and it must be distinguished from hypoxia.

Spatial disorientation

Loss of correct attitude awareness when visual cues are absent in cloud or at night; the pilot must rely on instruments rather than sensations of turning or climbing.

Carbon monoxide hazard

An odourless gas from engine or heater exhaust that causes headache and drowsiness; if suspected, shut off the heater, open vents, and land as soon as possible.

Thermal formation

Sun-heated ground warms the air above it, which rises as a bubble or column; thermals are strongest over dark, dry surfaces and weakest over water and dense forest.

Dry adiabatic lapse rate

Unsaturated air cools about 3 °C per 1000 ft (9.8 °C per 1000 m) as it rises; comparing this with the environmental lapse rate determines atmospheric stability.

Cold front effects

A narrow band of showers, a sharp wind shift, and a temperature drop as the front passes; soaring is poor during passage but improves behind the front in unstable air.

Mountain wave indicators

Lenticular clouds and a strong, smooth updraft on the windward side mark a mountain wave; severe turbulence occurs in the rotor below and downwind of the ridge.

Sea breeze formation

On sunny days land heats faster than the sea, so cooler air flows inland; the breeze front produces convergence lift and a marked wind shift useful for soaring.

Magnetic variation correction

The angle between true and magnetic north; magnetic heading equals true heading plus or minus variation, and compass heading adds the aircraft-specific deviation from the swing card.

One-in-sixty rule

A course error of 1° produces a lateral error of 1 nautical mile over 60 nautical miles; it allows quick estimation of drift and the correction needed.

Wind triangle

A vector diagram combining true course and true airspeed with wind direction and speed to give true heading and groundspeed; it is the basis of dead-reckoning navigation.

Chart scale 1:500 000

On this cross-country chart, 1 cm represents 5 km on the ground; relief is shown by contours and shading, and the scale is used to measure track and distance.

Winch launch cable break

If the cable breaks below about 200 ft, lower the nose, land ahead, and do not turn back; above that height, turn downwind only with sufficient height and airspeed.

Aerotow release signal

The tow pilot rocks the wings to signal release; the glider pilot pulls the release knob, confirms separation, then turns away from the tow aircraft.

Final approach speed

Approach at about 1.3 times the stall speed plus half the wind speed, adjusting airbrakes to reach the aiming point; a glider cannot go around, so the decision must be early.

Pre-takeoff checks

Confirm controls free and correct, altimeter set, airbrakes locked, ballast secured, canopy locked, harness fastened, and the launch signal agreed with the wing runner.

Critical angle of attack

The angle at which airflow separates from the wing, about 15° for most gliders; stall occurs at this angle regardless of airspeed, so a glider can stall at any speed.

Load factor in turns

In a level turn, load factor equals 1 divided by the cosine of the bank angle; at 60° bank it is 2, and stall speed rises by the square root of the load factor.

Induced drag behaviour

Drag caused by lift production; it decreases as airspeed increases and increases with lift coefficient, so it dominates at low speed and high angle of attack.

Aspect ratio formula

Span squared divided by wing area; a high aspect ratio reduces induced drag and improves glide ratio, which is why racing gliders have long, narrow wings.

Ground effect

Reduced induced drag when the wing is within about one wingspan of the ground; it increases lift and causes float during the landing flare.