Brunei DCA CPL(A) VFR Communications key terms

A pilot's repetition back to ATC of a clearance or instruction to confirm it was received and understood correctly. It is mandatory for runway, level and heading instructions and must include the aircraft callsign.

The unique identifier used in radio communication, normally the aircraft registration or a flight number, often shortened by ATC after initial contact. Correct use prevents confusion between aircraft on the same frequency.

The first radio call to a new ATC unit, which states the unit being called, the aircraft callsign, position, altitude and intentions. It establishes two-way communication before any clearance is issued.

The internationally agreed words and sentence patterns used in radio telephony, such as ROGER, WILCO and STANDBY. Using standard phrases reduces misunderstanding, especially when reception is poor or the speaker has an accent.

A radio term meaning the previous transmission was received and understood. It does not mean agreement, approval or that any action will be taken, and it is never a substitute for a required readback.

A radio term meaning the message was received, understood and will be complied with. It combines understanding with a commitment to act, so it is used for instructions rather than plain information.

A phrase telling the other station to wait and that a reply or further information will follow shortly. It is not an approval or clearance, so the pilot must not act on the original request until a proper answer arrives.

A request for the previous transmission to be repeated in full. It is used when reception was incomplete or unclear, and the reply should be given slowly and clearly, with the callsign repeated.

The word spoken before a corrected version of a transmission that contained an error. The recipient must disregard the earlier version and apply only the corrected message, which is then read back.

An instruction to leave the current radio frequency and contact another unit or channel. The pilot should read back the new frequency and callsign, then switch over and make initial contact on the new frequency.

The emergency radio frequency 121.5 MHz, monitored by many units for distress and urgency calls. It is used only for genuine emergencies or when contact cannot be established on the assigned frequency.

A radio receiver circuit that mutes background noise when no usable signal is present. Incorrect squelch settings can silence weak but important transmissions, so it should be set so that weak signals remain audible.

A number from one to five reported by radio to describe how well a transmission is being received, from unreadable to perfectly readable. It helps both stations judge whether repetition or a frequency change is needed.

Airborne equipment that replies to ground radar interrogations with a code and, in some modes, pressure altitude. ATC uses these replies for identification, separation and traffic information, so the assigned code must be set accurately.

The instruction to select a specific four-digit transponder code, for example SQUAWK 4271. The pilot sets the code, confirms it on the display and reads it back to ATC to verify correct entry.

The transponder mode that transmits pressure altitude to ground radar, allowing ATC to see the aircraft's level. Pilots must ensure the correct altimeter setting is set so that transmitted altitude is accurate.

An instruction to press the identification button on the transponder, which causes a distinctive flash on the controller's radar display. It is used only on request to confirm radar identification of the aircraft.

The process by which ATC establishes that a particular radar return or transponder reply belongs to a specific aircraft. It may be achieved by squawk, ident or position report, and is confirmed to the pilot.

A radio message giving the aircraft's location, level, next reporting point and estimated time over it. It is required in some airspace and on request, and forms the basis of traffic and search and rescue information.

A defined geographical location at which an aircraft reports its position to ATC or on a flight information frequency. Reports at these points allow controllers to track progress and pass relevant traffic or weather information.

A service providing information useful for safe flight, such as weather, traffic and aerodrome conditions, without issuing clearances or separating aircraft. Pilots remain responsible for their own separation and collision avoidance.

A transmission alerting a pilot to other known aircraft in the vicinity, usually with position, level and direction of movement. It helps the pilot see and avoid, but does not relieve the pilot of lookout responsibility.

Automatic Terminal Information Service, a continuous recorded broadcast of current aerodrome conditions including weather, runway in use and other essential information. Pilots note the identifying letter and report it on first contact.

The pressure value set on the altimeter subscale to give correct altitude indications, such as QNH or QFE. ATC may pass the current setting, and pilots must read it back and set it correctly.

A request to ATC for the current surface wind at the aerodrome, often made on final approach or before takeoff. The reply gives direction and speed, and the pilot reads back the figures.

An authorisation to move an aircraft on the manoeuvring area along a specified route, often including holding points and crossing instructions. The pilot must read back the route and any holding or crossing restrictions.

The radio channel used for communication with ground control, covering taxi, towing and aerodrome surface movement. Aircraft normally change from ground to tower frequency when ready for departure at the holding point.

The channel used by aerodrome control for takeoff, landing and circuits, including traffic in the vicinity of the aerodrome. Pilots contact tower when ready for departure or when arriving at the circuit.

A designated position where an aircraft must stop before entering a runway or taxiway, unless cleared. It is normally marked by signs and markings, and the pilot must not pass it without an explicit clearance.

An instruction allowing an aircraft to enter the runway and position for takeoff, without permission to begin the takeoff roll. It must be read back in full, including any associated conditions.

An explicit authorisation to begin the takeoff roll on a specified runway. It is never assumed, must be read back, and becomes invalid if the aircraft has not started the roll within a reasonable time.

The standard traffic pattern flown around an aerodrome for landing, with defined crosswind, downwind, base and final legs. Circuit calls inform other pilots and ATC of position and intentions.

A radio report made when the aircraft turns onto the downwind leg, stating callsign, position and intention, such as touch and go or full stop. It allows ATC and other traffic to sequence arrivals.

The last leg of the circuit or instrument approach, aligned with the runway and descending for landing. Pilots report on final and must receive landing clearance before touchdown where one is required.

An authorisation to land on a specified runway, issued by aerodrome control. It must be read back, and if not received by touchdown the aircraft should normally go around unless local procedures allow otherwise.

A manoeuvre abandoning an approach to landing, normally announced to ATC with the callsign and intention. The pilot climbs and follows the published or instructed pattern, and ATC then issues further instructions.

The spoken distress signal used when an aircraft is threatened by serious or imminent danger and needs immediate assistance. It is repeated three times, followed by callsign, nature of problem, position, level and intentions.

The spoken urgency signal used when a situation is serious but does not yet require immediate assistance, such as an engine problem or illness on board. It is repeated three times and followed by details and intentions.

The VHF frequency 121.5 MHz designated for emergency transmissions, also monitored for distress by many stations. It allows an aircraft in trouble to reach any listening unit, including military and coastal stations.

A situation where the pilot cannot transmit or receive on the assigned frequency. Standard actions include trying other frequencies, squawking 7600 and following the published lost communication procedures.

The transponder code selected to indicate a radio communication failure to ATC. It alerts controllers to the problem so they can apply special procedures and provide separation while the aircraft continues.

Ground signals given by a tower using a lamp, used to communicate with an aircraft that cannot use radio. Steady green means cleared to land or taxi, while flashing red means return to the starting point.

The category of controlled or uncontrolled airspace, lettered A to G, that determines whether a clearance is required and what services are provided. VFR pilots must know the class along their planned route.

An authorisation from ATC for an aircraft to proceed under specified conditions, such as a level, route or approach. It must be read back and complied with, and any inability to comply must be advised immediately.

A document describing a planned flight under visual flight rules, filed with the relevant authority. It supports alerting services and search and rescue, and must be closed on arrival to avoid unnecessary action.