HK PPL Radiotelephony key terms

The mandatory repetition by the receiving station of clearances, instructions and safety-related information, so the issuing controller can confirm the message was received and understood correctly.

An authorisation from a controller for an aircraft to proceed under specified conditions, such as a take-off, landing, route or level clearance, which must be read back before acting on it.

A radiotelephony acknowledgement meaning the last transmission was received in full, but not that any action or agreement is implied; it does not replace a required readback.

A contraction of 'will comply', used to acknowledge an instruction and confirm that the pilot intends to carry it out; it does not substitute for reading back a clearance.

The standard phraseology for 'yes', used when answering a direct question from another station. Its negative counterpart is 'negative' rather than 'no'.

The standard request for a repeat of all or part of a transmission. It is used instead of 'repeat', which has a separate meaning in artillery and gunnery contexts.

A phrase telling the other station to wait and that the caller will initiate the next contact. It is not an approval or clearance and no action may be taken on it.

A phrase used when a transmission has contained an error and the correct version follows. The word signals that the previous content should be disregarded and replaced.

The standardised set of words and sentence patterns agreed internationally for air-ground communication, designed to be unambiguous and understood by all stations regardless of native language.

The prescribed format for transmitting messages, covering station identification, message order, pronunciation of numerals and letters, and the use of ICAO spelling alphabet words.

The internationally agreed set of words (Alfa, Bravo, Charlie and so on) used to spell out letters and letter groups so that they are not misheard over a noisy radio channel.

The rule that numerals in messages are spoken digit by digit, with specific pronunciations such as 'tree' for three and 'fife' for five, to reduce confusion on poor-quality channels.

The unique identifier used to address a station on the radio, such as an aircraft registration, flight number or abbreviated form once established, and the unit being called.

The first transmission from an aircraft to a new station, which must include the station addressed, own call sign, position, level and any other information required to establish the service.

A shortened form of an aircraft or unit call sign permitted once communication is established, such as using only the last two characters of the registration, to reduce channel congestion.

A request asking another station to report the readability of a transmission, answered on a five-point scale from one (unreadable) to five (perfectly readable).

The reported quality of a received transmission, expressed as a number from one to five, where five means perfectly readable and one means unreadable, sometimes with a signal strength suffix.

An instruction to move to another radio frequency, normally read back in full with the new frequency so that both stations remain in contact on the correct channel.

The aerodrome unit responsible for traffic on manoeuvring areas other than runways, issuing taxi clearances and instructions to aircraft and vehicles on taxiways and aprons.

An authorisation to move an aircraft on the ground along a specified route, normally including the destination and any holding point, which must be read back before movement begins.

A designated position on a taxiway where an aircraft must stop and wait before entering a runway or another protected area, usually identified by a runway designator.

An instruction permitting an aircraft to enter the runway and position itself ready for take-off, without authorisation to begin the take-off roll.

The authorisation for an aircraft to begin the take-off run on a specified runway. It is only issued by the aerodrome control unit and must always be read back.

The authorisation for an aircraft to land on a specified runway, normally including any surface wind and preceding traffic information, and requiring a full readback.

A clearance whose validity depends on a stated condition, such as waiting for landing traffic to vacate, phrased so the condition is stated first and the clearance second.

An instruction or pilot decision to abandon an approach and climb away, used when landing cannot be completed safely, and which must be acknowledged promptly by radio.

Any unauthorised presence of an aircraft, vehicle or person on a protected runway area, a serious hazard that correct readback and holding point discipline are designed to prevent.

Information passed to a pilot about known or observed aircraft nearby, giving position, level, direction and type where known, to help the pilot see and avoid other traffic.

A pilot's report that the aircraft described in traffic information has been visually acquired, allowing the controller to apply reduced separation or issue a following clearance.

The reply used when a pilot has not seen the traffic described or has failed to establish radio contact as requested; it tells the controller that visual acquisition has not occurred.

A transmission giving the aircraft's location relative to a known point or navigation aid, together with level and next position, used when flying outside radar coverage.

A statement of the altitude or flight level at which an aircraft is flying or cleared to fly, expressed in the standard format and read back when assigned by a controller.

An instruction to climb to and then remain at a specified level, which must be read back with the level stated so any misunderstanding is caught immediately.

An instruction to descend to and then remain at a specified level, read back in full by the pilot, often issued during arrival sequencing or when leaving the cruise.

Authorisation to carry out a specified instrument or visual approach to a nominated runway, usually including the level to maintain until established on a published segment.

The published procedure followed when an approach cannot be completed to landing, involving a climb and routing to a defined point; the pilot must announce going around.

The time at which an aircraft expects to be over a specified point, normally given in hours and minutes, used by controllers to plan sequencing when radar is unavailable.

The spoken distress signal, repeated three times, used only when an aircraft is threatened by serious or imminent danger and requires immediate assistance from all stations.

The spoken urgency signal, repeated three times, used when a situation is concerning but does not yet require immediate assistance, such as an ill passenger or a non-critical malfunction.

The structured transmission following MAYDAY, giving station identity, nature of distress, intentions, position, level and fuel, so rescuers can act without further questions.

The transmission following PAN PAN, stating the nature of the problem, the crew's intentions and position, and what assistance, if any, is required from other stations.

The designated very high frequency channel reserved for distress and urgency traffic, monitored by stations to allow immediate communication when normal channels are congested.

Loss of two-way communication, handled by following the published procedures for the applicable conditions, including squawking the appropriate code and continuing per the flight plan.

The four-digit setting selected on the aircraft's transponder, including special codes for radio failure, unlawful interference and general emergencies, announced to the controller.

An instruction to press the identification button on the transponder so the aircraft's radar return is highlighted on the controller's display, normally acknowledged without further readback.

A transmission sent when no reply has been received, stating the message in the hope that some station is listening, used during radio failure or when contact cannot be established.