RA-Aus BAK flashcards

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

Four forces of flight

Lift, weight, thrust and drag. In steady unaccelerated flight lift equals weight and thrust equals drag; any imbalance accelerates the aircraft toward the greater force.

Lift equation

L = ½ × density × velocity squared × wing area × lift coefficient. Lift increases with the square of airspeed, so doubling airspeed quadruples lift at a fixed angle of attack.

Angle of attack

The angle between the wing chord line and the relative airflow. It is not the same as pitch attitude or climb angle and directly determines lift and stall margin.

Critical angle of attack

The angle at which airflow separates and the wing stalls. The wing stalls at this angle regardless of airspeed, weight or bank, so stalls can occur at any speed.

Induced versus parasite drag

Induced drag falls as airspeed rises; parasite drag rises with the square of airspeed. Total drag is lowest where the two curves cross, giving best glide performance.

Load factor in a turn

n = 1 divided by cosine of bank angle. At 60 degrees bank the load factor is 2 g, which raises stall speed by about 41 percent.

Density altitude

Pressure altitude corrected for temperature. It rises with high elevation, heat, humidity and low pressure, reducing engine power, thrust and lift, and lengthening take-off runs.

Standard atmosphere

At sea level: 1013.25 hPa, 15 degrees Celsius, density 1.225 kilograms per cubic metre. Temperature falls about 2 degrees Celsius per 1000 feet in the lower atmosphere.

Lateral stability

Stability about the roll axis, provided mainly by dihedral, which makes a dropped wing produce more lift and roll the aircraft back toward level.

Pre-flight walk-around

An external inspection of structure, control surfaces, fuel quantity and sumps, oil level, tyres, brakes, pitot and static ports, and security of caps and cowlings before flight.

Weight and balance formula

Total moment equals weight times arm. Centre of gravity equals total moment divided by total weight, and must lie within forward and aft limits for every loading.

Vx versus Vy

Vx is best angle of climb for obstacle clearance; Vy is best rate of climb for fastest altitude gain. Vx increases with altitude until it meets Vy.

Carburettor ice conditions

Ice can form with outside air temperatures between about minus 10 and plus 25 degrees Celsius when humidity is high. Apply carburettor heat and expect a temporary power drop.

Wake turbulence avoidance

Vortices sink and drift with the wind. Land beyond the preceding aircraft's touchdown point and take off before its rotation point to stay clear of the wake.

Rejected take-off decision

Before rotation, reject the take-off for any abnormality. After lift-off with insufficient runway remaining, land straight ahead rather than attempt a turn back.

Radio call content

A standard call states the station addressed, own callsign, position, altitude and intentions. Clearances and hold-short instructions must be read back accurately.

Sterile cockpit

A period, typically during taxi, take-off, approach and landing, when non-essential conversation and tasks are avoided so both pilots focus on flying.

Accident versus incident

An accident involves death, serious injury or substantial aircraft damage. An incident is a safety-related occurrence that does not reach the accident threshold but is still reportable.

Mandatory occurrence report

A report required for defined serious events such as runway incursions, near misses, airspace infringements and engine failure in flight, submitted to the safety authority.

Just culture

A reporting philosophy where unintentional errors are reported and used for learning, while only reckless or deliberately unsafe acts attract punitive action.

Confidential reporting scheme

A channel allowing hazards and near misses to be reported with identifying details protected, supplementing mandatory occurrence reporting and encouraging disclosure.

Reporting timeline

Serious occurrences must be notified promptly, commonly within 24 to 72 hours, with a fuller written report following. Late reporting can hinder investigation and safety action.

Preserving occurrence evidence

After an occurrence, do not disturb wreckage or move the aircraft unless needed for safety or rescue, and record witness details and conditions promptly.

Human factors chain

Fatigue, distraction, stress, complacency and poor communication precede most occurrences. Checklists, briefings and sterile-cockpit periods help break the chain.

Airworthiness directives

Mandatory instructions issued by the regulator to correct unsafe conditions. Compliance is required within the stated time and must be recorded in the aircraft records.

Maintenance release

A certification issued by a licensed engineer or approved person confirming that maintenance has been completed and the aircraft is airworthy for return to service.

Aircraft logbooks

Records of airframe, engine and propeller hours, inspections, defects and releases. Entries must be made promptly and signed to maintain an accurate maintenance history.

Four-stroke engine cycle

Induction, compression, combustion (power) and exhaust. Each cylinder completes the cycle in four piston strokes, driving the propeller through the crankshaft.

Magneto check

During run-up, each magneto is selected in turn. An excessive drop or rough running indicates an ignition fault, and the aircraft should not be flown.

Fuel sump drain check

Drain fuel from the sumps before flight and inspect for water, sediment and correct grade. Contaminated fuel can cause engine failure shortly after take-off.

Alternator failure indication

A failed alternator shows a discharge or zero charge indication. Shed electrical load, conserve battery power and plan to land at the nearest suitable aerodrome.

Spongy brake pedal

A soft or spongy pedal indicates air in the hydraulic system or a fluid leak. The system must be bled and rectified before flight, not merely pumped up.