- ATO/ATC blade fuses are standard size and the most common type of fuse for automotive and marine applications, but can be used in other electrical applications that require circuit protection. Commonly mounted in a fuse block, fuse holder or panel. Available in 1, 3, 5, 7.5, 10, 15, 20, 25, 40 amps.
- IATA's operations work groups develop operational solutions for all areas affecting aircrafts and airlines, either on ground or in flight.
Abbreviation Definition. The duration between the last take-off time requested by the aircraft operator and the take-off slot allocated by the Central Flow Management Unit following a regulation communicated by the FMP, in relation to an airport (airport delay) or sector (en-route delay) location. NB: ATC may request Big Jet to confirm when Runway 18 is vacated A Conditional Taxi Clearance Conditional clearances may expedite traffic flow, but there are risks. Read-back must be in full and in the same sequence as given. A taxi clearance, shown below, allows taxi after another action has first taken place ie. The condition of the clearance.
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This page lists some common phraseologies used in the communication between pilots and ATC.
- Items in italic need to be replaced by the relevant information.
- Lists are dialogues between the pilot and the controllers; we assume that station is the controller's callsign and that callsign is the pilot's callsign.
- Most items critical for the safety of flight (such as new headings/altitudes...) must be read back (repeated) by the pilot; this allows the controller to check whether the pilot understood them correctly. In case readback is required, this will be mentioned. Do not just say 'roger' in those cases – that's a common error. If an item is read back wrongly, the controller should just state it again.
- Some clearances (authorizations) may be combined in a single sentence for brevity.
For a detailed tutorial in ATCing, please take a look at the ATC Tutorial.
- 8Ground/tower controller coordination
General
Phraseology | Meaning | Remarks |
---|---|---|
Affirmative (abbreviation: affirm) | Yes | |
Negative | No | |
| A controller asks the pilot to change radio frequency and contact another controller; the pilot acknowledges the instruction and then changes frequency. | If the new controller does not respond, change to the previous frequency and inform ATC. |
Roger | I received your information | This sentence is often abused; it should not be used in case a readback (repetition of the message you heard, for safety reasons) is required. |
Wilco | Will comply | This sentence should not be used in case a readback (repetition of the message you heard, for safety reasons) is required. |
Say again | Please repeat your last message | |
Standby | Please wait | Often said by a controller because (s)he's busy at the moment |
Correction | Disregard what has been said immediately before (as it's erroneous) and replace it with the words that follow. | Example: Callsign, taxi to holding point runway 22 via N – correction, via A means: Callsign, taxi to holding point runway 22 via A. |
Unable, reason | The pilot is not able to execute the instruction given by a controller for safety reasons. |
Clearance
Phraseology | Meaning | Remarks |
---|---|---|
| Used by a pilot to check if the controller can hear him well. | |
| Used by a pilot flying under instrument flight rules to ask which SID he is going to use for departure. | This is not an authorization to take off. |
| The pilot asks for permission to pushback (be pushed away from the stand by a tug). At the end of the maneuver, the aircraft should be headed direction. | |
| The pilot asks for permission to start up the engines. |
Atc Slot Definition Dictionary
Taxi
Phraseology | Meaning | Remarks |
---|---|---|
| The pilot asks for authorization to taxi; the controller authorizes him to taxi to an holding point, reached which the pilot should stop and ask/wait for further instructions. | Refer to an updated aeronautical chart to know taxiway names. |
| The pilot asks for authorization to taxi and for controller guidance, as (s)he's not familiar with the airport; the controller tells the pilot when to perform each turn. | Progressive taxi should only be used in case you get lost and can't solve the situation on your own. |
| The controller instructs the pilot to give way to another plane. | |
| The pilot needs to cross a runway and asks the ground controller for permission; the ground controller obtains a clearance from Tower (not reported here) and authorizes the pilot to cross. | |
| The ground controller asks the pilot to stop at position (a taxiway entrance, runway crossing...). As soon as the pilot reaches the designated point, (s)he must inform the controller that the aircraft is 'holding short'. | |
| The ground controller asks the pilot to stop immediately/maintain the current position. |
Remark: the controller might ask you to follow an aircraft or to perform a maneuver after another aircraft has cleared the way (conditional clearance). In that case, (s)he will say 'After the aircraft type...'.
Takeoff and departure
Phraseology | Meaning | Remarks |
---|---|---|
| The tower controller instructs the aircraft to enter the runway, position itself in the center and await further clearance. |
|
| The controller authorizes the aircraft to take off. |
|
| The controller cancels the existing takeoff clearance (e.g. because there is an obstacle on the runway). | This form is used when the aircraft has not started the takeoff roll yet. |
| The controller cancels the existing takeoff clearance (e.g. because there is an obstacle on the runway). | This form is used when the aircraft has already started the takeoff roll. |
Climb, cruise, descent
Phraseology | Meaning | Remarks |
---|---|---|
| The pilot has just been transferred to another controller and contacts him/her announcing the current altitude, the altitude (s)he was cleared to and any other ATC clearances previously assigned (SID/STAR, etc.). The controller identifies the aircraft on the radar screen, announces so and, if needed, assigns a new squawk code/issues further clearances. | New clearances/squawk codes should be assigned only if needed and must be read back. |
| Climb (or descend) to new altitude and hold it until further instructions are given. | Flight levels below FL100 should be referred to as two digit numbers (to avoid confusion with headings). |
| The aircraft is instructed to turn left/right to another heading. | The pilot must execute the turn according to ATC instructions, even if it's not the most intuitive/direct way. |
| Proceed along a straight line towards fix/navaid. |
Approach and landing
Phraseology | Meaning | Remarks |
---|---|---|
| After reaching the first fix of the ILS approach, follow the altitudes and flight path specified by the approach procedure. |
|
| The pilot must tell ATC when (s)he has caught the localizer and glideslope. | |
| The pilot should continue the approach. | Generally used when the landing runway is still obstructed and the controller needs to delay the landing clearance. This is not an authorization to land. |
| Make number circles to the left/right, then continue on the original heading. | Used by ATC to space an aircraft from the one in front. |
| Enter (exit) the holding pattern (circular/oval path, usually drawn at the beginning of the approach). If entering, continue to fly it until further clearance. | Used by ATC to space an aircraft from the one in front. |
| Land on the specified runway. | This is the one and only clearance that authorizes an aircraft to land. |
| Abort the landing and fly the published missed approach. | Used when a controller deems that the landing would be unsafe. |
| The pilot aborts the landing and flies the published missed approach. | Used when the pilot deems that the landing would be unsafe. |
Atc Slot Definition Meaning
Emergency situations
Phraseology | Meaning | Remarks |
---|---|---|
| The pilot declares an emergency (immediate attention is required). |
|
| The pilot tells the controller (s)he's in distress, but that immediate attention is not required. | |
Pilot:Station, TCAS RA. | The pilot tells the controller (s)he has received a TCAS resolution advisory. | In case a TCAS RA is issued, follow the TCAS instructions and ignore any conflicting ATC instructions. |
Pilot: Unable, TCAS RA. | Used in case the instructions given by ATC can not be followed because they are conflicting to the ones given by the TCAS. | |
Pilot:Station, clear of conflict, returning to assigned clearance. | Used after the TCAS has stated the aircraft is clear of conflict. |
Ground/tower controller coordination
Aircraft crossing runways
This phraseology is used when a pilot needs to cross an active runway and the ground/tower controllers coordinate to issue crossing clearances.
Atc Slot Definition Synonyms
Pilot | Ground controller | Tower controller | Remarks |
---|---|---|---|
Callsign, holding short runway, request permission to cross. | The pilot tells the ground controller (s)he's at the entrance of the active runway runway and asks the ground controller for permission to cross it. | ||
Station Ground to Station Tower. | The ground controller calls the tower controller on an intercom. | ||
Station Tower. | The tower controller replies. | ||
Callsign on holding, request permission to cross runway runway, Station Ground. | The ground controller asks the tower controller whether the aircraft can cross the active runway or not. | ||
Cleared to cross runway, Station Tower. | The tower controller clears the aircraft to cross the runway. | ||
Station Ground. | The ground controller ends the call. | ||
Station Tower. | The tower controller ends the call. | ||
callsign, cleared to cross runway. | The ground controller instructs the aircraft to cross (on frequency). | ||
Cleared to cross runway, callsign. | The pilot reads back the instructions. |
Change of active runways
This phraseology is used by the tower controller to inform Ground that the active runways have changed.
Atc Slot Definition Synonym
Ground controller | Tower controller | Remarks |
---|---|---|
Station Tower to Station Ground. | The tower controller calls the ground controller on the intercom. | |
Station Ground. | The ground controller answers the call. | |
Arrival runway is runway, departure runway is runway, Station Tower. | The tower controller informs the ground controller of the new runway configuration in use. | |
Arrival runway is runway, departure runway is runway, copied. | The ground controller reads back the information. | |
Station Tower. | The tower controller ends the call. | |
Station Ground. | The ground controller ends the call. |
External links
- All Clear? Toolkit, Eurocontrol
Takeoff and departure
Phraseology | Meaning | Remarks |
---|---|---|
| The tower controller instructs the aircraft to enter the runway, position itself in the center and await further clearance. |
|
| The controller authorizes the aircraft to take off. |
|
| The controller cancels the existing takeoff clearance (e.g. because there is an obstacle on the runway). | This form is used when the aircraft has not started the takeoff roll yet. |
| The controller cancels the existing takeoff clearance (e.g. because there is an obstacle on the runway). | This form is used when the aircraft has already started the takeoff roll. |
Climb, cruise, descent
Phraseology | Meaning | Remarks |
---|---|---|
| The pilot has just been transferred to another controller and contacts him/her announcing the current altitude, the altitude (s)he was cleared to and any other ATC clearances previously assigned (SID/STAR, etc.). The controller identifies the aircraft on the radar screen, announces so and, if needed, assigns a new squawk code/issues further clearances. | New clearances/squawk codes should be assigned only if needed and must be read back. |
| Climb (or descend) to new altitude and hold it until further instructions are given. | Flight levels below FL100 should be referred to as two digit numbers (to avoid confusion with headings). |
| The aircraft is instructed to turn left/right to another heading. | The pilot must execute the turn according to ATC instructions, even if it's not the most intuitive/direct way. |
| Proceed along a straight line towards fix/navaid. |
Approach and landing
Phraseology | Meaning | Remarks |
---|---|---|
| After reaching the first fix of the ILS approach, follow the altitudes and flight path specified by the approach procedure. |
|
| The pilot must tell ATC when (s)he has caught the localizer and glideslope. | |
| The pilot should continue the approach. | Generally used when the landing runway is still obstructed and the controller needs to delay the landing clearance. This is not an authorization to land. |
| Make number circles to the left/right, then continue on the original heading. | Used by ATC to space an aircraft from the one in front. |
| Enter (exit) the holding pattern (circular/oval path, usually drawn at the beginning of the approach). If entering, continue to fly it until further clearance. | Used by ATC to space an aircraft from the one in front. |
| Land on the specified runway. | This is the one and only clearance that authorizes an aircraft to land. |
| Abort the landing and fly the published missed approach. | Used when a controller deems that the landing would be unsafe. |
| The pilot aborts the landing and flies the published missed approach. | Used when the pilot deems that the landing would be unsafe. |
Atc Slot Definition Meaning
Emergency situations
Phraseology | Meaning | Remarks |
---|---|---|
| The pilot declares an emergency (immediate attention is required). |
|
| The pilot tells the controller (s)he's in distress, but that immediate attention is not required. | |
Pilot:Station, TCAS RA. | The pilot tells the controller (s)he has received a TCAS resolution advisory. | In case a TCAS RA is issued, follow the TCAS instructions and ignore any conflicting ATC instructions. |
Pilot: Unable, TCAS RA. | Used in case the instructions given by ATC can not be followed because they are conflicting to the ones given by the TCAS. | |
Pilot:Station, clear of conflict, returning to assigned clearance. | Used after the TCAS has stated the aircraft is clear of conflict. |
Ground/tower controller coordination
Aircraft crossing runways
This phraseology is used when a pilot needs to cross an active runway and the ground/tower controllers coordinate to issue crossing clearances.
Atc Slot Definition Synonyms
Pilot | Ground controller | Tower controller | Remarks |
---|---|---|---|
Callsign, holding short runway, request permission to cross. | The pilot tells the ground controller (s)he's at the entrance of the active runway runway and asks the ground controller for permission to cross it. | ||
Station Ground to Station Tower. | The ground controller calls the tower controller on an intercom. | ||
Station Tower. | The tower controller replies. | ||
Callsign on holding, request permission to cross runway runway, Station Ground. | The ground controller asks the tower controller whether the aircraft can cross the active runway or not. | ||
Cleared to cross runway, Station Tower. | The tower controller clears the aircraft to cross the runway. | ||
Station Ground. | The ground controller ends the call. | ||
Station Tower. | The tower controller ends the call. | ||
callsign, cleared to cross runway. | The ground controller instructs the aircraft to cross (on frequency). | ||
Cleared to cross runway, callsign. | The pilot reads back the instructions. |
Change of active runways
This phraseology is used by the tower controller to inform Ground that the active runways have changed.
Atc Slot Definition Synonym
Ground controller | Tower controller | Remarks |
---|---|---|
Station Tower to Station Ground. | The tower controller calls the ground controller on the intercom. | |
Station Ground. | The ground controller answers the call. | |
Arrival runway is runway, departure runway is runway, Station Tower. | The tower controller informs the ground controller of the new runway configuration in use. | |
Arrival runway is runway, departure runway is runway, copied. | The ground controller reads back the information. | |
Station Tower. | The tower controller ends the call. | |
Station Ground. | The ground controller ends the call. |
External links
- All Clear? Toolkit, Eurocontrol