NCAA Air Traffic Controller Licence flashcards

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

Class A airspace

Airspace in which only IFR flights are permitted; all flights are separated from each other by ATC. Typically above FL 195 or as designated by the state.

Class D airspace

Controlled airspace around an aerodrome where IFR and VFR flights require ATC clearance. IFR is separated from IFR; VFR receives traffic information only, not separation.

Radar separation minimum

Terminal radar: 3 NM lateral or 1,000 ft vertical below FL 290. At or above FL 290: 5 NM or 2,000 ft (1,000 ft in RVSM airspace).

Wake turbulence categories

Light ≤ 7,000 kg MTOW, Medium 7,000–136,000 kg, Heavy ≥ 136,000 kg, Super for the A380. Separation behind a Heavy is typically 5 NM for medium/light followers.

Squawk 7700

Transponder code indicating a general emergency. ATC must give priority, provide separation, and inform the pilot of the nearest suitable aerodrome and weather.

Squawk 7600

Transponder code indicating radio communication failure. ATC applies standard lost-communication procedures and separates the flight from other traffic.

Squawk 7500

Transponder code indicating unlawful interference (hijack). ATC notifies the appropriate authority and does not transmit information that could compromise the aircraft.

Standard holding pattern

Right-hand turns with 1-minute inbound legs below FL 140 and 1.5-minute legs at or above FL 140. Entry is direct, parallel, or teardrop.

Teardrop entry

Holding entry used when the aircraft approaches within 30° of the outbound leg; the aircraft turns 30° off the outbound heading, flies for the leg time, then turns to intercept the inbound.

Parallel entry

Holding entry used when the aircraft approaches from the non-holding side; the aircraft flies parallel to the outbound leg, then turns to intercept the inbound course.

Direct entry

Holding entry used when the aircraft approaches within 70° of the inbound course; the aircraft proceeds directly to the holding fix and turns into the pattern.

Clearance readback requirement

Pilots must read back route, level, heading, speed, frequency and runway clearances. 'Roger' or 'standby' is not an acceptable readback.

MAYDAY call

Distress signal transmitted three times, indicating grave and imminent danger requiring immediate assistance. ATC gives absolute priority and provides separation and assistance.

PAN PAN call

Urgency signal transmitted three times, indicating a condition concerning safety but not requiring immediate distress action. ATC gives priority but normal separation may continue.

Mode C tolerance

Altitude reported by Mode C must be within ±300 ft of the assigned level to be considered verified. Beyond tolerance, ATC must query the pilot.

250 kt speed limit

Below FL 100, the maximum indicated airspeed for all aircraft is 250 kt unless a higher speed is specifically authorised by the appropriate authority.

Approach speed restrictions

Typical ATC speed control on approach: 210 kt downwind, 180 kt base, 160 kt final. 'Resume normal speed' cancels the restriction.

IFR flight plan filing

ICAO flight plan must be filed at least 30 minutes before estimated departure for IFR flights. Changes require coordination with ATC or the parent ATS unit.

Flight plan change message

A 'CHG' message amends a filed flight plan; 'CNL' cancels it; 'DLA' reports delay; 'DEP' reports departure. Each must be transmitted to the appropriate ATS unit.

Longitudinal separation (procedural)

Non-radar separation: 10 minutes between aircraft on the same track, or 15 minutes where no navigation aid is available. Vertical separation is 2,000 ft above FL 290.

RVSM airspace

Reduced Vertical Separation Minima airspace between FL 290 and FL 410 where 1,000 ft vertical separation applies. Aircraft must be RVSM-approved and have operative altimetry.

Transition altitude

Altitude at or below which the aircraft's altimeter is set to local QNH. Above the transition level, standard pressure (1013.25 hPa) is used and levels are expressed as flight levels.

Transition level

Lowest flight level available for use above the transition altitude. It is determined by the appropriate ATS unit and may vary with atmospheric pressure.

QNH vs QFE

QNH is the altimeter setting that causes the altimeter to indicate altitude above mean sea level. QFE causes it to indicate height above the aerodrome reference point.

ATIS content

Automatic Terminal Information Service broadcast includes aerodrome identification, time, runway in use, surface wind, visibility, cloud, temperature, dew point, QNH and any significant trends.

ATIS phonetic designator

Each ATIS broadcast is identified by a letter of the phonetic alphabet (Alpha, Bravo, Charlie...) that changes with each new observation, so pilots can confirm they have current information.

SSR code assignment

Secondary surveillance radar codes are assigned by ATC from the allocated code list. Codes 7500, 7600 and 7700 are reserved for emergencies and must not be assigned.

Radar identification

Aircraft is identified by observing a position symbol on the radar display, by transponder code correlation, or by a turn onto a specified heading. Identification must be confirmed before separation.

Position report content

Position reports include aircraft identification, position, time, flight level, next position and estimated time over it, and the succeeding significant point.

Clearance limit

The point to which an aircraft is granted an ATC clearance. Beyond this point, a further clearance is required before proceeding.

Minimum fuel vs emergency fuel

Minimum fuel indicates the aircraft can accept little or no delay. Emergency fuel (MAYDAY FUEL) indicates the aircraft cannot accept further delay and requires priority handling.

Traffic information phraseology

Traffic information includes relative bearing, distance, direction of flight and type of aircraft, e.g. 'traffic 10 o'clock, 5 miles, opposite direction, Boeing 737'.