KCAA ATPL Theory flashcards

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

Squawk 7500

Transponder code signifying unlawful interference with an aircraft. It alerts air traffic control to a hijacking or similar security emergency and triggers special handling procedures.

Chicago Convention Article 1

Recognises that every State has complete and exclusive sovereignty over the airspace above its territory, forming the legal basis for national control of airspace.

VFR visibility minimum

ICAO Annex 2 requires 8 km flight visibility at or above 3 050 m AMSL, 5 km below that level, and clear of cloud with surface in sight at or below 900 m AMSL.

Class 1 medical validity

Under ICAO Annex 1 a Class 1 medical certificate is valid for 12 months; many States reduce this to 6 months for pilots aged 40 and over.

Induced drag formula

Di = 1/2 rho V^2 S CL^2/(pi A e). It decreases as speed increases and increases with lift coefficient, so it dominates at low speed and high angle of attack.

Turbine engine N1

N1 is the rotational speed of the low-pressure spool, usually the fan or low-pressure compressor. It is a primary thrust parameter displayed as a percentage of design speed.

Pitot-static altimeter

The altimeter uses static pressure only. It converts pressure into indicated altitude according to a standard atmosphere, so it reads pressure altitude when set to 1013.25 hPa.

Gyroscopic rigidity

A spinning gyroscope maintains its axis fixed in space unless acted on by a torque. Attitude and heading indicators use this property for stable references.

Centre of gravity formula

CG = total moment divided by total mass, where each moment is mass multiplied by arm. Moving a mass aft moves the CG aft; moving it forward moves the CG forward.

Density altitude formula

Density altitude = pressure altitude + 120 x (OAT - ISA temperature at that altitude). High density altitude reduces performance and increases take-off and landing distances.

V1 decision speed

V1 is the speed at which the pilot must decide to continue the take-off or stop. It is determined by runway length, mass, thrust and braking performance.

Final reserve fuel

Fuel required to hold for 30 minutes at 1 500 ft above the alternate aerodrome at holding speed, included in the operational fuel plan and not usable for normal flight.

Time of useful consciousness

The time from loss of oxygen to inability to act coherently. It is about 30-60 seconds at FL 350 and 15-20 seconds at FL 400.

Somatogravic illusion

A false sensation of climbing during forward acceleration, caused by otolith stimulation. It can lead to an inappropriate nose-down correction during take-off or go-around.

Dark adaptation

The eye's adjustment to low light, taking about 30 minutes. Rods become more sensitive and central vision is poor, so off-centre scanning is needed at night.

Inverted-U arousal

Performance is best at moderate arousal. Too little arousal causes underload and missed cues; too much causes narrowed attention, stress and errors.

QNH

The altimeter setting that makes the altimeter indicate elevation above mean sea level at the aerodrome. It is used below the transition altitude.

Freezing rain

Rain containing supercooled water that freezes on impact. It causes rapid clear ice on aircraft and is a severe icing hazard, often associated with warm fronts.

Radiation fog

Fog formed under clear skies, light winds and high humidity after sunset, when the ground cools and the air reaches saturation. It usually dissipates after sunrise.

Microburst

A concentrated downdraft that spreads out at the surface, producing sudden headwind then tailwind changes. It causes severe low-level wind shear and is dangerous on approach.

Great circle

The shortest path between two points on a sphere, lying on a plane through the Earth's centre. Its track changes continuously, unlike a rhumb line.

VOR radial

A magnetic bearing from a VOR station. The aircraft's CDI shows the selected radial; TO/FROM indicates whether the aircraft is approaching or leaving the station.

RAIM

Receiver Autonomous Integrity Monitoring. It uses redundant GPS signals to detect and isolate faulty satellite signals, and it must be available for certain RNAV approaches.

Transition altitude

The altitude at which climbing aircraft change from local QNH to standard pressure 1013.25 hPa. The transition level is the corresponding level for descending aircraft.

MAYDAY

The international distress call used when an aircraft is in grave and imminent danger and requires immediate assistance. It is transmitted on 121.5 MHz or the active ATC frequency.

CAT II minima

A precision approach category with a decision height of 100 ft and runway visual range of about 300 m, requiring approved aircraft, crew and ground facilities.

Sterile flight deck

A rule prohibiting non-essential conversation and activity during taxi, take-off, approach and landing, and below 10 000 ft, to protect attention.

Critical angle of attack

The angle of attack at which the wing reaches maximum lift coefficient. Beyond it airflow separates, lift decreases and the wing stalls regardless of speed.

Adverse yaw

Yaw opposite to the intended turn caused by increased induced drag on the down-going aileron wing. Coordinated rudder prevents it and keeps the turn balanced.

Ground effect

Reduction in induced drag and increase in lift when an aircraft flies within about one wingspan of the ground, caused by interference with wingtip vortices.

CRAFT clearance

A memory aid for IFR clearance items: Clearance limit, Route, Altitude, Frequency and Transponder. Pilots read back the clearance to confirm understanding.

121.5 MHz

The international aeronautical emergency frequency. It is used for distress and urgency communications and for emergency locator transmitter signals.