SERA.8015 Air traffic control clearances

(a)Air traffic control clearances shall be based solely on the following requirements for providing air traffic control service:

(1)Clearances shall be issued solely for expediting and separating air traffic and be based on known traffic conditions which affect safety in aircraft operation. Such traffic conditions include not only aircraft in the air and on the manoeuvring area over which control is being exercised, but also any vehicular traffic or other obstructions not permanently installed on the manoeuvring area in use.

(2)ATC units shall issue such ATC clearances as necessary to prevent collisions and to expedite and maintain an orderly flow of air traffic.

(3)ATC clearances shall be issued early enough to ensure that they are transmitted to the aircraft in sufficient time for it to comply with them.

(b)Operation subject to clearance:

(1)An air traffic control clearance shall be obtained prior to operating a controlled flight, or a portion of a flight as a controlled flight. Such clearance shall be requested through the submission of a flight plan to an air traffic control unit.

(2)When a flight plan specifies that the initial portion of a flight will be uncontrolled, and that the subsequent portion of the flight will be subject to air traffic control service, the flight crew shall obtain the clearance from the appropriate air traffic control unit prior to entering the area where controlled flight will be commenced.

(3)When a flight plan specifies that the initial portion of a flight will be subject to air traffic control service, and that the subsequent portion will be uncontrolled, the aircraft shall normally be cleared to the point at which the controlled flight terminates.

(4)The pilot-in-command of an aircraft shall inform the air traffic control unit if an air traffic control clearance is not satisfactory. In such cases, the air traffic control unit will issue an amended clearance, if practicable.

(5)Whenever an aircraft has requested a clearance involving priority, a report explaining the necessity for such priority shall be submitted, if requested by the appropriate air traffic control unit.

(6)Potential reclearance in flight. If, prior to departure, it is anticipated that, depending on fuel/energy endurance and subject to reclearance in flight, a decision may be taken to proceed to a revised destination aerodrome, the appropriate air traffic control units shall be so notified by the insertion in the flight plan of information concerning the revised route (where known) and the revised destination.

(7)An aircraft operated on a controlled aerodrome shall not taxi on the manoeuvring area without clearance from the aerodrome control tower and shall comply with any instructions given by that unit.

(8)When vectoring or assigning a direct routing not included in the flight plan, which takes an IFR flight off published ATS route or instrument procedure, an air traffic controller providing ATS surveillance service shall issue clearances such that the prescribed obstacle clearance exists at all times until the aircraft reaches the point where the pilot re-joins the flight plan route or joins a published ATS route or instrument procedure.

(c)Clearances for transonic flight

(1)The air traffic control clearance relating to the transonic acceleration phase of a supersonic flight shall extend at least to the end of that phase.

(2)The air traffic control clearance relating to the deceleration and descent of an aircraft from supersonic cruise to subsonic flight shall seek to provide for uninterrupted descent at least during the transonic phase.

(d)Contents of clearances An air traffic control clearance shall indicate:

(1)aircraft identification as shown in the flight plan;

(2)clearance limit;

(3)route of flight:

(i)the route of flight shall be detailed in each clearance when deemed necessary;

(ii)the phrase “cleared flight planned route” shall not be used when granting a re-clearance;

(4)level or levels of flight for the entire route or part thereof and changes of levels if required;

(5)any necessary instructions or information on other matters, such as ATFM departure slot if applicable, approach or departure manoeuvres, communications and the time of expiry of the clearance.

(e)Read back of clearances, instructions and safety-related information

(1)The flight crew shall read back to the air traffic controller safety-related parts of ATC clearances and instructions which are transmitted by voice. The following items shall always be read back:

(i)ATC route clearances;

(ii)clearances and instructions to enter, land on, take off from, hold short of, cross, taxi and backtrack on any runway; and

(iii)runway-in-use, altimeter settings, SSR codes, newly assigned communication channels, level instructions, heading and speed instructions; and

(iv)transition levels, whether issued by the controller or contained in ATIS broadcasts.

(2)Other clearances or instructions, including conditional clearances and taxi instructions, shall be read back or acknowledged in a manner to clearly indicate that they have been understood and will be complied with.

(3)The controller shall listen to the read-back to ascertain that the clearance or instruction has been correctly acknowledged by the flight crew and shall take immediate action to correct any discrepancies revealed by the read-back.

(4)Voice read-back of CPDLC messages shall not be required, unless otherwise specified by the ANSP.

(5)Vehicle drivers operating or intending to operate on the manoeuvring area shall read back to the air traffic controller safety-related parts of instructions which are transmitted by voice, e.g. instructions to enter, hold short of, cross and operate on any operational runway or taxiway.

(6)The controller shall listen to the read-back to ascertain that the instruction has been correctly acknowledged by the vehicle driver and shall take immediate action to correct any discrepancies revealed by the read-back.

(ea)Changes in clearance regarding route or level

(1)When issuing a clearance covering a requested change in route or level, the exact nature of the change shall be included in the clearance.

(2)When traffic conditions will not permit clearance of a requested change, the word ‘UNABLE’ shall be used. When warranted by circumstances, an alternative route or level shall be offered.

(eb)Clearance related to altimetry

(1)For flights in areas where a transition altitude is established, the vertical position of the aircraft shall, except as provided for in (5) below, be expressed in terms of altitudes at or below the transition altitude and in terms of flight levels at or above the transition level. While passing through the transition layer, the vertical position shall be expressed in terms of flight levels when climbing and in terms of altitudes when descending.

(2)The flight crew shall be provided with the transition level in due time prior to reaching it during descent.

(3)Except when it is known that the aircraft has already received the information in a directed transmission, an QNH altimeter setting shall be included in:

(i)the descent clearance, when first cleared to an altitude below the transition level;

(ii)the approach clearance or the clearance to enter the traffic circuit;

(iii)the taxi clearance for departing aircraft.

(4)A QFE altimeter setting shall be provided to aircraft on request or on a regular basis in accordance with local arrangements.

(5)When an aircraft has been given clearance to land or where an aircraft has been informed that the runway is available for landing at AFIS aerodromes and that aircraft is completing its approach using atmospheric pressure at aerodrome elevation (QFE), the vertical position of that aircraft shall be expressed in terms of height above aerodrome elevation during that portion of its flight for which QFE may be used, except that it shall be expressed in terms of height above runway threshold elevation:

(i)for instrument runways if the threshold is 2 m (7 ft) or more below the aerodrome elevation; and

(ii)for precision approach runways.

(ec)Conditional clearances Conditional phrases, such as ‘behind landing aircraft’ or ‘after departing aircraft’, shall not be used for movements affecting the active runway(s), except when the aircraft or vehicles concerned are seen by the appropriate controller and pilot. The aircraft or vehicle causing the condition in the clearance issued shall be the first aircraft/vehicle to pass in front of the other aircraft concerned. In all cases, a conditional clearance shall be given in the following order and consist of:

(1)the call sign;

(2)the condition;

(3)the clearance; and

(4)a brief reiteration of the condition.

(f)Coordination of clearances

(1)An air traffic control clearance shall be coordinated between air traffic control units to cover the entire route of an aircraft or a specified portion thereof as described in provisions (2) to (6).

(2)An aircraft shall be cleared for the entire route to the aerodrome of first intended landing:

(i)when it has been possible, prior to departure, to coordinate the clearance between all the units under whose control the aircraft will come; or

(ii)when there is reasonable assurance that prior coordination will be effected between those units under whose control the aircraft will subsequently come.

(3)When coordination as in (2) has not been achieved or is not anticipated, the aircraft shall be cleared only to that point where coordination is reasonably assured; prior to reaching such point, or at such point, the aircraft shall receive further clearance, holding instructions being issued as appropriate.

(4)When prescribed by the ATS unit, aircraft shall contact a downstream air traffic control unit, for the purpose of receiving a downstream clearance prior to the transfer of control point.

(i)Aircraft shall maintain the necessary two-way communication with the current air traffic control unit whilst obtaining a downstream clearance.

(ii)A clearance issued as a downstream clearance shall be clearly identifiable as such to the pilot.

(iii)Unless coordinated, downstream clearances shall not affect the aircraft’s original flight profile in any airspace, other than that of the air traffic control unit responsible for the delivery of the downstream clearance.

(5)When an aircraft intends to depart from an aerodrome within a control area to enter another control area within a period of thirty minutes, or such other specific period of time as has been agreed between the area control centres concerned, coordination with the subsequent area control centre shall be effected prior to issuance of the departure clearance.

(6)When an aircraft intends to leave a control area for flight outside controlled airspace, and will subsequently re-enter the same or another control area, a clearance from the point of departure to the aerodrome of first intended landing may be issued. Such clearance or revisions thereto shall apply only to those portions of the flight conducted within controlled airspace.