Section 3, Chapter 2 - Approach Surveillance Flashcards
What determines the area of responsibility for Approach Surveillance Services provided by an Approach Surveillance Control unit?
The area of responsibility is determined by factors including the coverage of ATS surveillance systems and requires approval by the CAA.
What services are provided by Approach Surveillance Control units and what factors influence these services according to CAP 493?
Types of Services Provided:
* Within Controlled Airspace: Radar Control Service.
* Outside Controlled Airspace: Procedural Service, Deconfliction Service, Traffic Service, or Basic Service.
Extent of ATS Surveillance Services:
* Depends on the ATS surveillance system and operational procedures approved by the CAA, as described in MATS Part 2.
Possible Services:
* Surveillance Radar Approaches.
* Vectoring/sequencing to a pilot-interpreted final approach aid.
* Flightpath monitoring of approaches using a pilot-interpreted final approach aid.
* ATS surveillance services to departing aircraft.
* ATS surveillance services to transit aircraft through the area of Approach Radar Control responsibility.
System Suitability:
* Certain ATS surveillance systems are not suitable for providing separation during radar approaches.
What are the co-ordination requirements for Approach Surveillance controllers according to CAP 493?
Direct Co-ordination:
* Approach Surveillance controllers may need to co-ordinate flights directly with Aerodrome Control and Area Control units.
Procedures:
* Detailed co-ordination procedures are described in MATS Part 2.
Under what conditions can an approach surveillance controller take control of an inbound aircraft according to CAP 493?
An approach surveillance controller can take control of an inbound aircraft if:
- The aircraft has been transferred to the approach surveillance controller by the approach controller.
- The aircraft is the subject of a ‘radar release’ from Area Control.
What are the procedures for providing weather information to inbound aircraft by the approach surveillance controller according to CAP 493?
Initial Weather Information:
* Transmit latest weather observations to aircraft on radar approaches as early as practicable, unless already provided by Approach/Aerodrome Control or acknowledged by pilot via ATIS.
Revised/Additional Information:
* Any revised or additional weather information must be passed to the pilot while the aircraft remains under the approach surveillance controller’s jurisdiction.
What are the procedures for providing altimeter settings to aircraft according to CAP 493?
QNH:
* Provide the QNH before the aircraft commences final approach.
* Aerodrome and threshold elevations available on request.
QFE:
* Provide the QFE at the pilot’s request or if local procedures require.
What are the obstacle clearance criteria for radar approaches as per CAP 493?
Criteria Details:
* Obstacle clearance criteria for radar approaches are detailed on aerodrome approach charts for each runway.
Pilot Responsibility:
* Pilots using altitude must perform their own conversion to obtain an obstacle clearance altitude.
What are the requirements for providing position information to pilots during radar approaches according to CAP 493?
Circuit Legs:
* Pass position information to the pilot at least once on each leg of the circuit.
Straight-in Approach:
* Pass position information at least once before the aircraft commences final descent.
Note: Range marks on extended runway centrelines indicate distance from touchdown.
Range rings typically indicate distance from the radar aerial head.
What information must be provided to aircraft by the controller prior to or upon commencement of vectoring to final approach according to CAP 493?
General Vectoring Information:
* Inform the pilot that the aircraft will be vectored to intercept the final approach.
* Specify the type of final approach.
* Specify the runway in use.
SRA (Surveillance Radar Approach) Information:
* Angle of the nominal descent path or recommended descent gradient.
* Termination range.
* Applicable obstacle clearance altitude/height.
* Procedure to follow in the event of radio communications failure if not published, using standard phraseology from CAP 413.
What are the terrain clearance procedures for vectoring arriving aircraft according to CAP 493?
General Terrain Clearance:
* Apply terrain clearance in accordance with Section 1, Chapter 6.
ATC Surveillance Minimum Altitude Charts (ATCSMACs):
* Published in the UK AIP, indicating minimum altitudes for vectoring arriving aircraft.
* Controllers must not use altitudes below those on SMAC except for specific, approved final approach procedures.
Exceptional Cases:
* Higher minimum altitudes may be specified to avoid TAWS nuisance warnings.
* Further details for these exceptions are included in MATS Part 2.
What are the procedures for vectoring aircraft to the final approach according to CAP 493?
Establishing on Final Approach Track:
* Vector aircraft to be established on the final approach track at a distance no closer than:
1. 2 NM before the Final Approach Fix (FAF) for ILS, MLS, VOR, NDB, or SRA.
2. The Intermediate Fix (IF) waypoint for an RNP approach.
Vectoring Through Final Approach Track:
* Advise the pilot if the aircraft needs to be vectored through the final approach track before joining from the opposite side.
Positioning for Level Flight:
* Ensure a period of level flight of at least 1 NM for independent parallel approaches:
1. At the published procedure height/altitude before descent at the FAF.
2. At a lower level if detailed in MATS Part 2 for precision approaches and permitted by the aerodrome’s ATCSMAC.
Exceptions:
* Continuous Descent Approach (CDA) procedures or emergencies.
What are the procedures for Continuous Descent Approach (CDA) according to CAP 493?
Operational Procedures and Use:
* Details included in MATS Part 2.
Level Allocation:
* Allocate levels according to CDA procedure.
* Ensure levels allow glide path or final approach descent path interception without level flight segment once CDA has commenced.
Descent Instructions:
* Issue descent instructions accordingly.
Distance Information:
* Provide distance from touchdown when issuing descent clearance.
* Provide distance information at other specified times as described in MATS Part 2.
What are the procedures for precision approaches (ILS or MLS) according to CAP 493?
Vectoring onto Localiser:
* Vector aircraft onto the ILS/MLS localiser or an appropriate closing heading offset up to 45° (30° for parallel approaches).
* Continue giving heading instructions until the aircraft is established on the localiser.
* Do not instruct pilots to establish on the localiser outside the localiser DOC.
* Provide additional heading instructions if necessary until within DOC.
Descent Clearance Techniques:
* Technique 1: Clear for ILS/MLS approach if descent to procedure altitude/height at the final approach fix or lower level as per ATCSMAC.
* Technique 2: Issue conditional clearance to descend on the ILS/MLS glidepath once established on the localiser.
* Technique 3: Instruct to report established on the localiser and maintain assigned level until further instructions:
1. Clear for the approach.
2. Clear to descend on the glidepath.
3. Give alternative level instructions.
Additional Notes:
* Use “maintain” to ensure separation from traffic below.
* Monitor Mode C/Mode S altitude reporting until established on the localiser.
* Do not instruct descent on ILS/MLS if the glidepath intersect is outside DOC.
Phraseology:
* Refer to CAP 413 for phraseology.
* Use “Microwave” for MLS in RTF and telephone coordination to avoid confusion with ILS.
What are the procedures for non-precision approaches according to CAP 493?
Types of Non-Precision Approaches:
* Approaches without ground-based electronic descent guidance (e.g., localiser only, VOR, NDB, SRAs).
* Rely on the pilot crossing the FAF at the published procedure altitude/height.
Vectoring to Final Approach:
* Vector onto final approach track or a heading to close the track at ≤ 45° (≤ 30° for parallel approaches).
* Ensure the aircraft is established on the final approach track with a descent profile to cross the FAF at the correct altitude/height.
Range Checks:
* Non-DME Procedures: Pass a range check before clearing for the approach; additional distance information as needed.
* DME Procedures: Pass a range check and clear for approach once established on the final approach track.
What are the procedures for RNP approaches according to CAP 493?
RNP Approach Guidance:
* Utilizes GNSS with ABAS (e.g., RAIM) or SBAS for lateral/vertical guidance.
Routing to IAF:
* Permit aircraft to route to the Initial Approach Fix (IAF) with a descent profile crossing the IAF not below the published procedure height/altitude.
Vectoring:
* Vector onto final approach track or a closing heading ≤ 45° (≤ 30° for parallel approaches) to establish by the Intermediate Fix (IF).
* Provide descent clearances to cross IF at the published procedure height/altitude or cross the FAF at the published height/altitude if permitted by ATCSMAC.
Positioning:
* Do not position aircraft closer to touchdown than the IF.
* Positioning inside the IF may prevent the approach from being flown due to onboard RNP equipment.
Following the Approach:
* Once cleared, the pilot follows the lateral and vertical profile of the RNP approach.
Phraseology:
* Detailed in CAP 413.
What are the conditions and requirements for clearing an aircraft for a visual approach according to CAP 493?
Conditions for Clearance:
* Detailed in Chapter 1.
Descent Restriction:
* Clearance must include a descent restriction to ensure the aircraft remains within controlled airspace.
What are the procedures for integrating VFR and Special VFR flights into the landing sequence according to CAP 493?
Sequencing Information:
* Provide sufficient information to VFR or Special VFR pilots to integrate safely into the landing sequence.
VFR Flights:
* If vectors or specific routing instructions are given, instruct the pilot to advise if it prevents remaining in VMC.
Special VFR Flights:
* Ensure vectors allow the pilot to remain clear of cloud, keep the surface in sight, and avoid obstacles by visual reference to the surface.
What are the procedures for clearance to land according to CAP 493?
Notification to Approach/Aerodrome Control:
* Notify when an aircraft making a radar approach is approximately 8 NM from touchdown.
* If no landing clearance is received, make a subsequent check at 4 NM.
* Pass clearance to land or alternative instructions to the aircraft before it reaches 2 NM from touchdown.
Landing Clearance Indicator System:
* Use the system (if installed) for giving clearance to land or missed approach instructions.
Surface Wind Information:
* Indicated surface wind, passed with the landing clearance, may be transmitted to the aircraft at the approach surveillance controller’s discretion.
What are the key procedures for Surveillance Radar Approaches (SRAs) according to CAP 493?
Approval Requirement:
* SRAs can only be conducted where the ATS surveillance system and procedure are CAA-approved for a specific aerodrome.
Situation Display:
* Must clearly indicate the final approach track and ranges from touchdown.
* Discontinue approach and instruct missed approach if these indicators fail and the aircraft cannot continue visually.
Gear Check Reminder:
* Remind aircraft to check their gear when on final approach.
Termination Ranges:
* Ranges at which SRAs terminate vary by approval.
* Refer to CAP 413 for appropriate phraseology.
What are the conditions for an SRA terminating at 2 NM from touchdown according to CAP 493?
Advisory Heights and Ranges:
* Pass advisory heights for maintaining the nominal glidepath and ranges from touchdown at each nautical mile.
Minimum Descent Height Check:
* Instruct the pilot to check their minimum descent height one mile before advisory heights are discontinued.
Discontinuation of Advisory Heights:
* Discontinue advisory heights at the one above the highest Obstacle Clearance Height (OCH).
What are the conditions for an SRA terminating at less than 2 NM from touchdown according to CAP 493?
Advisory Heights and Ranges:
* Pass advisory heights and ranges from touchdown at each half mile.
Transmission Intervals:
* Transmissions must not be interrupted for more than 5 seconds from 4 NM until approach termination.
Minimum Descent Height Check:
* Instruct the pilot to check their minimum descent height at 2 NM.
Discontinuation of Advisory Heights:
* Discontinue advisory heights at the one above the highest OCH or at 1 NM, whichever is sooner.
Controller Duties:
* Controller’s duties are strictly related to the SRA and no other responsibilities.
What are the details regarding glidepath and advisory height for SRAs according to CAP 493?
Glidepath Angles and Advisory Heights:
* Detailed in MATS Part 2, appropriate to the type of equipment.
Advisory Levels Calculation:
* Published in UK AIP, initially calculated based on QNH or QFE datum and rounded up to the nearest 10 ft.
* Adjusted for the other datum, resulting in non-round values for any particular approach.
Rounding Advisory Levels:
* Unless requested otherwise by the pilot, advisory levels passed by ATC should be rounded up to the nearest 10 ft to minimize potential misinterpretation.
Datum Indication:
* Advisory levels prefixed with “height” (QFE) or “altitude” (QNH).
* Pilots using QNH should be passed the aerodrome/threshold elevation before commencing final descent.
Rounding Values:
* Rounded values for SRAs are detailed in MATS Part 2.
What are the procedures for issuing missed approach instructions according to CAP 493?
Circumstances Requiring Missed Approach Instructions:
* On instructions from Approach/Aerodrome Control.
* No landing clearance received before 2 NM from touchdown (or other agreed range).
* Aircraft is dangerously positioned on final approach.
Circumstances Advising Missed Approach:
* Unlikely to complete a successful approach.
* Not visible on the situation display during the last 2 NM of approach.
* Position or identification of the aircraft is in doubt during final approach.
Missed Approach Instructions:
* Include level to climb and heading instructions if necessary.
* Instruct to contact Approach Control or remain with the approach surveillance controller.
Windshear Alert Response:
* Prepare for the aircraft to exceed the missed approach altitude.
* Provide traffic information, instructions, and advice to ensure safety.
* Expect significantly higher rates of climb due to maximum thrust.
* Aircraft may exceed cleared level, especially with low level-off altitudes.
* Windshear alerts take precedence over TCAS alerts.
What are the procedures for discontinuing a radar approach according to CAP 493?
Immediate Notification:
* Inform the aircraft immediately if a radar approach cannot be continued due to clutter, system failure, or communication issues.
Before Final Approach:
* Clear the aircraft to an appropriate facility for an alternative approach.
* Provide procedural separation.
After Commencing Final Approach:
* Continue the approach visually or using an alternative aid.
* If not possible, clear the aircraft for an alternative approach as above.
What are the procedures for controlling departing aircraft by approach surveillance controllers according to CAP 493?
Unit-Specific Procedures:
* Vary from unit to unit and detailed in MATS Part 2.
Conflicting Departures:
* Departing traffic conflicting with inbound aircraft receiving an ATS surveillance service must be transferred to the approach surveillance controller.
* The approach surveillance controller is responsible for providing separation unless authorised procedures ensuring automatic separation are in operation.
