Section 1, Chapter 4 - Control Of Traffic Flashcards
What is the rule regarding the control of a controlled flight by air traffic control units?
A controlled flight shall be under the control of only one air traffic control unit at any given time.
What does an ATC clearance authorize and what is it based on?
An ATC clearance authorizes an aircraft to proceed under conditions specified by an ATC unit. Clearances are based solely on known traffic conditions, which include:
- Aircraft in the air and on the manoeuvring area over which control is being exercised.
- Vehicular traffic or other obstructions not permanently installed on the manoeuvring area in use (SERA.8015(a) and SERA.8015(a)(1)).
Clearances are required for any flight, or portion of a flight, which is provided with an air traffic control service.
How does a pilot request an ATC clearance and what should they do if the clearance is not satisfactory?
- A pilot requests an ATC clearance by submitting a flight plan (SERA.8015(b)(1)).
- The clearance can be issued directly to the aircraft or through an approved agency, such as another ATSU.
- If the clearance is not satisfactory, the pilot shall inform ATC.
- In such cases, controllers will issue an amended clearance if practicable (SERA.8015(b)(2)).
Do ATC clearances allow pilots to violate any regulations?
No, ATC clearances do not constitute authority to violate any regulations established by the DfT, CAA, or other appropriate authority. Controllers should not issue clearances that imply permission to breach regulations, especially in respect of the low flying rules.
What are the requirements for data link communications used to facilitate clearance delivery?
When data link communications are used to facilitate clearance delivery:
- Two-way voice communications between the pilot and the air traffic control unit providing the clearance should be available.
- Unless specified in the MATS Part 2, voice read-back of data link messages is not required.
What must ATC clearances include according to SERA.8015(d)?
ATC Clearances Must Include (SERA.8015(d)):
Aircraft Identification:
- As shown in the flight plan.
Clearance Limit:
- The specified limit up to which the aircraft is authorized to proceed.
Route:
- Where prescribed in MATS Part 2.
Levels of Flight:
- For the entire route or part thereof and any changes of levels if required.
Note: The joining level assigned in an airborne joining clearance to enter controlled airspace is considered acceptable with respect to the level content of a clearance.
Necessary Instructions or Information:
- Such as approach or departure maneuvers, communications, and the time of expiry of the clearance.
Note: The time of expiry of the clearance indicates when the clearance will be automatically cancelled if the flight has not commenced (GM1.SERA.8015(d)(5)).
What is a clearance limit and how is it specified?
A clearance limit is the point to which an aircraft is granted an ATC clearance. It shall be specified by naming:
- An aerodrome.
- A reporting point.
- A controlled or advisory airspace boundary.
When shall an aircraft be cleared for the entire route to the aerodrome of first intended landing?
An aircraft shall be cleared for the entire route to the aerodrome of first intended landing when:
- It has planned to remain within controlled or advisory airspace throughout the flight.
- There is reasonable assurance that prior coordination will be effected ahead of the passage of the aircraft.
What is the clearance limit for flights not remaining within controlled or advisory airspace throughout the flight?
The clearance limit for all other flights shall be the boundary of controlled or advisory airspace.
What must be specified if the clearance for the levels covers only part of the route, and why?
If the clearance for the levels covers only part of the route, it is important to specify that part to enable the pilot to comply with radio failure procedures.
What may the CAA issue concerning the clearance of inbound aircraft to certain aerodromes?
The CAA may issue special instructions concerning the clearance of inbound aircraft to certain aerodromes.
What is the order and composition of conditional clearances according to SERA.8015(ec)?
Order and Composition of Conditional Clearances (SERA.8015(ec)):
Callsign:
* The callsign of the aircraft or vehicle being given the clearance.
Condition:
* The condition, e.g., “behind…”
Identification:
* Identification of the subject of the condition, e.g., aircraft, reporting point, level, etc.
Clearance:
* The clearance itself.
Reiteration:
* A brief reiteration of the condition.
What is an example of a conditional clearance, and where can details on their use at aerodromes be found?
Example of a Conditional Clearance:
* “(Callsign), behind the landing (aircraft type), via (holding point), runway (designator) line up behind.”
Additional Details:
* The use of conditional clearances at aerodromes, especially concerning active runways, is detailed in Section 2.
What should a controller do if unable to clear an aircraft according to the requested route, and what expression should not be used for re-clearances?
If unable to clear an aircraft according to the requested route, the controller shall explain the reason when issuing the clearance. The expression “cleared flight plan route” is not to be used for re-clearances (SERA.8015(d)(3)(ii)).
What must a controller do if a direct routing takes an aircraft outside the boundaries of controlled or advisory airspace?
If a direct routing takes an aircraft outside the lateral or vertical boundaries of controlled or advisory airspace, the controller must inform the pilot. The pilot will then decide whether to accept or decline the new route.
What should controllers say if traffic conditions do not permit clearance of a pilot’s requested change in route?
If traffic conditions do not permit clearance of a pilot’s requested change in route, controllers shall use the word “unable” in RTF phraseology (SERA.8015(ea)(2)).
What should a pilot do if their aircraft is unable to comply with RNAV requirements, and what actions must ATSUs take?
If an aircraft is unable to comply with RNAV requirements, the pilot must advise the ATSU on initial contact using the phrase “Negative RNAV.”
Aerodrome ATSUs must:
- Advise the relevant ACC.
- Add the phrase “Negative RNAV” to the end of estimate and coordination messages, unless automatic message transfer facilities exist.
What are the rules for allocating cruising levels to aircraft?
Allocation of Cruising Levels:
Requested Level:
- Normally, the cruising level requested in the flight plan is to be allocated.
- If the flight planned level is not available, the nearest appropriate vacant level is to be allocated.
Priority:
- When two or more aircraft are at the same cruising level, the preceding aircraft shall normally have priority.
- An aircraft at a cruising level shall normally have priority over other aircraft requesting that level.
- Request Denial:
- When traffic conditions do not permit clearance of a pilot’s requested change in level, controllers shall use the word “unable” in RTF phraseology and offer an alternative level (SERA.8015(ea)(2)).
FL195:
- FL195 must not be allocated as a cruising level.
What are the rules for assigning cruising levels on ATS routes and in Class C airspace above FL195?
Rules for Assigning Cruising Levels:
ATS Routes:
- Cruising levels normally assigned on ATS routes are contained in the UK AIP (ENR 3.2) section.
- Other levels may be allocated according to MATS Part 2 (UK Reg (EU) No. 923/2012 SERA.5020(b)).
Class C Airspace Above FL195:
- The table of cruising levels shall apply (UK Reg (EU) No. 923/2012 SERA.5020(b) and Appendix 3):
- Westbound: FL200, FL220, FL240, FL260, FL280.
- Eastbound: FL210, FL230, FL250, FL270.
What are the cruising levels at or above FL410 up to FL660 according to the semi-circular rule?
Cruising Levels at or Above FL410 up to FL660 (Semi-Circular Rule):
* Eastbound: FL410, FL450, FL490, etc.
* Westbound: FL430, FL470, FL510, etc.
How are cruising levels assigned to IFR aircraft outside controlled airspace below FL195?
Cruising Levels Assignment Outside Controlled Airspace Below FL195:
Cruising levels shall be assigned according to the table of cruising levels (UK Reg (EU) No. 923/2012 SERA.5025(a) and Appendix 3). However, this is not required (ORS4 No. 1578):
- At or below 3,000 ft amsl.
- Above 3,000 ft amsl, when aircraft are operated:
1. In conformity with levels allocated by an appropriate air traffic service unit.
2. In accordance with instrument approach procedures notified by the CAA in relation to an aerodrome.
What happens when an amendment is made to an ATC clearance?
When an amendment is made to a clearance:
- The new clearance shall be read in full to the pilot.
- The new clearance automatically cancels any previous clearance.
- If the original clearance included a restriction (e.g., “cross ABC FL150 or below”), the restriction is automatically canceled with the new clearance unless it is reiterated with the revised clearance.
What should a controller consider when issuing a clearance that amends the vertical profile of an aircraft on a SID?
When issuing a clearance that amends the vertical profile of an aircraft on a SID, a controller must:
- Recognize that the new clearance automatically cancels the vertical profile of the SID.
- If the profile contains a restriction providing vertical separation from conflicting traffic on another SID, reiterate the restriction (e.g., “climb now FL120 cross XYZ 5,000 feet or above”) unless separation is ensured by other means.
What must controllers do when issuing instructions that amend the SID route?
When issuing instructions that amend the SID route, controllers must confirm the level profile to be followed, e.g.:
- “Fly heading 095, climb now FL80.”
- “Route direct EFG, stop climb at altitude 5,000 feet.”
Who can instruct controllers to withhold a clearance, and where are the relevant procedures listed?
The Aerodrome Operator and certain other authorized persons can instruct controllers to withhold a clearance. The personnel authorized under civil aviation legislation and the procedures to be adopted when detaining aircraft are listed in unit instructions.
What should a controller do if instructed to withhold take-off clearance?
If a controller is instructed to withhold take-off clearance, the controller should take reasonable steps to establish the authenticity and powers of the person giving the instruction.
When must a controller withhold clearance to take-off?
A controller must withhold clearance to take-off when it is known that an aircraft has been detained by a police or HM Customs officer.
What steps should a controller take if they believe a planned flight is liable to endanger life or involve a breach of legislation?
If a controller believes a planned flight is liable to endanger life or involve a breach of legislation, they should:
- Warn the pilot of the hazardous condition or apparent infringement and obtain an acknowledgment of the message.
- In the case of an infringement of legislation, warn the pilot that if they take off, the facts will be reported to the appropriate authority.
- If the pilot still requests take-off clearance after acknowledging the warning, advise the pilot, when traffic permits, that there are no traffic reasons to restrict take-off.
- Record the warning and any comment made by the pilot in the ATC Watch Log.
What is essential when pilots disregard warnings or when detained aircraft depart without clearance, and where can the recommended phraseology be found?
Clear and precise messages must be passed to the pilots concerned, and acknowledgments obtained. The recommended phraseology appears in CAP 413. Further transmissions may be necessary to ascertain the pilot’s intentions.
What should ATC do if a pilot has not obtained prior permission to proceed to a destination aerodrome that requires it?
In no circumstances is either an ATC clearance or permission to take-off to be withheld solely because the pilot has not obtained prior permission to proceed to their destination aerodrome. This matter is between the pilot and the appropriate Aerodrome Operator and is normally of no concern to ATC.
What should a controller do if an aerodrome abroad is closed, and can they withhold take-off clearance because of this?
If an aerodrome abroad is closed, the information is to be relayed by RTF to any aircraft in flight bound for that aerodrome. Action may be limited to aircraft which have departed less than 30 minutes after the message has been received. A controller has no authority to withhold take-off clearance because the intended destination is closed.
How is pertinent air traffic data normally displayed and where can instructions and procedures for data display be found?
Pertinent air traffic data is normally displayed on flight progress strips. Instructions for marking handwritten strips appear in Appendix D. Procedures for data display methods are described in MATS Part 2.
How are requests for clearances prioritized, and what happens when two or more flights of different categories request clearance?
Prioritization of Clearance Requests:
- Requests for clearances are normally dealt with in the order received and issued according to the traffic situation.
- Certain flights are given priority over others according to a categorization table.
- When two or more flights of different categories request clearance, the flight with the highest category is dealt with first.
- Flow control procedures are implemented and actioned by the Central Flow Management Unit, and a flow control priority is allocated automatically on receipt of a flight plan.
What should a pilot do upon receiving the estimated delay for an approach concerning fuel status?
Upon receiving the estimated delay for an approach, a pilot will determine whether they can continue to the aerodrome or divert to a suitable alternative aerodrome.
What does a pilot’s declaration of “MINIMUM FUEL” indicate, and what is the final reserve fuel?
A pilot’s declaration of “MINIMUM FUEL” indicates that no further fuel diversion options are available, and the aircraft is committed to land at the nominated aerodrome with not less than ‘final reserve fuel’.
Final reserve fuel:
- Typically 30 minutes of flight for turbine-powered aircraft.
- Typically 45 minutes of flight for piston-powered aircraft.
(Note: “MINIMUM FUEL” RTF phraseology is not universally used by every aircraft operator and pilot.)
Are controllers required to provide priority to aircraft that have declared “MINIMUM FUEL” or are becoming short of fuel?
No, controllers are not required to provide priority to pilots of aircraft that have declared “MINIMUM FUEL” or have indicated that they are becoming short of fuel.
How should controllers respond to a pilot’s declaration of “MINIMUM FUEL”?
Controllers shall respond to a pilot’s declaration of “MINIMUM FUEL” by:
- Confirming the estimated delay they can expect to receive expressed in minutes, or no delay, when the pilot is en-route to, is joining, or is established in an airborne hold.
- Expressing the remaining track mileage from touchdown if the aircraft is being vectored to an approach (SERA.11012(a)).
What should controllers do at locations where EATs are not issued until the delay reaches a particular value?
At locations where EATs (Estimated Approach Times) are not issued until the delay reaches a particular value, controllers must provide a general indication of the delay, based on the best information available at that time (see ENR 1.9-4).
What should controllers do after providing the estimated delay or remaining track mileage to a pilot who has declared “MINIMUM FUEL”?
Controllers shall keep pilots informed of any increase in delay or increase in track mileage after the pilot’s initial declaration of “MINIMUM FUEL,” following which the controller can expect the pilot to declare an emergency. Once in possession of either the estimated delay or remaining track mileage, the pilot will determine whether they can continue to the aerodrome with or without declaring a fuel emergency.
What RTF phraseology should pilots use to declare an emergency and what priority do controllers provide to such aircraft?
Pilots should use the RTF phraseology “MAYDAY, MAYDAY, MAYDAY” or “MAYDAY, MAYDAY, MAYDAY FUEL” to declare an emergency. Controllers shall provide these aircraft with flight priority category A (SERA.11012(b)).
What should controllers do if pilots allude to a medical emergency on board but do not formally declare an emergency or indicate serious illness?
Controllers should ask the pilots to confirm if they are declaring an emergency. If there is no formal declaration of an emergency, controllers are not required to give priority to the flight.
