Section 1, Chapter 16 - Low Visibility Operations

Question 2

What are the special considerations for CATII/III ILS operations during low visibility conditions?

Answer 2

• Guarding the Localiser Sensitive Area (LSA):
• The LSA is a rectangular area contained within parallel lines 137 meters either side of the runway centerline.
• It extends from the localiser aerial to the beginning of the runway in use.
• For departing aircraft, the LSA exists only between the departing aircraft and the localiser aerial.

Question 3

What are the expectations for pilots during CAT IIIB operations on Runway 25?

Answer 3

• Pilots can expect ILS signals to be fully protected from interference during the final stages of the approach.
• This protection is maintained from the time Low Visibility Procedures (LVP) are notified as in operation until they are notified as cancelled.

Question 4

What are the ATC actions for safeguarding during CAT IIIB operations on Runway 25?

Answer 4

Conditions for Requesting Safeguarding:

Telephone BIAL Control Centre when any of the following conditions occur (record the time in the Watch Log):
* Visibility 2000m or less
* Cloud ceiling 300ft or less
* Any fog on or in the vicinity of the airfield

Actions Before Declaring Safeguarding Complete:

• Confirm the status of 25 ILS with DEO. If DEO is unavailable, use the METCOM display status indicator (report anything other than “U3” to DEO/WM).
• Check IRVR is serviceable. If not, initiate manual RVR observations and inform BIAL & WM.
• Telephone RFFS with the phrase: “Initiating Weather Standby for low visibility/cloud, Free Ranging is suspended.”
• Suspend Free Ranging. Instruct all vehicles known to be free ranging to vacate the manoeuvring area or request clearance. Broadcast “Free ranging is suspended.”
• Confirm the status of Work in Progress (WIP) affecting the manoeuvring area. After consulting SCOD, the ADM may allow WIP to continue with the phrase: “Safeguarding checks have been carried out, except for the work in progress.”

Note:
BIAL will not report “Safeguarding checks complete” unless all items 1-5 have been carried out.
Safeguarding cannot be implemented while there is WIP affecting the manoeuvring area.

Question 5

What are the steps to implement safeguarding once the ADM has declared “Safeguarding Complete”?

Answer 5

• Update METCOM status to “SAFEGUARDING”.
• Place a green “Safeguarding” information strip in CSD.
• Advise SCOD: “Safeguarding complete”.
• Annotate ATC Watch Log: “Safeguarding complete”.

Question 6

What are the steps to cancel safeguarding, ensuring LVPs are not declared before cancellation?

Answer 6

• Advise SCOD: “Safeguarding is cancelled”.
• Update METCOM to “Normal”.
• Remove the information strip from CSD.
• Stand down Weather Standby with RFFS.
• Telephone BIAL Control Centre and state: “Safeguarding cancelled”.
• Annotate ATC Watch Log.

Question 7

What are the ATC actions for commencing Low Visibility Procedures (LVPs)?

Answer 7

Conditions for Enforcing LVPs:

• RVR (TD reading, MP if TD u/s) / Met visibility decreases to 800m or less
• Cloud ceiling is less than 200ft
• LVPs cannot be declared until Safeguarding is implemented.

Steps to Commence LVPs:
* Ensure “Safeguarding” has been completed.
* On AGL, start all four standby generators and confirm 4 green “on-load” indications with no alarms (advise ADM of any failures).
* Select Cat 2/3 on AGL Panel. Ensure no traffic is between A2 and A1 (or cleared to A1) without a runway clearance and the lead-on selected.
* Update METCOM status to “LVPs” (METCOM will declare LVPs in force on ATIS).

Once Steps 1-4 Are Complete and Traffic Situation Allows:
* Create an “LVPs in force” strip and share with all ATC Operational positions.
* Declare “LVPs in force” to all aircraft and vehicles active on the airfield (individual confirmation required).

Notification and Logging:

• Annotate the Watch Log.
• Declare “LVPs in force” by telephone to the following agencies:
• RFFS
• BIAL (request they inform ADM)
• DEO (when on duty)
• EGAA WM
• PC OS
• Also advise Military and PSNI.

Question 8

What are the key components of Low Visibility Procedures (LVPs) at aerodromes supporting Category II or III operations?

Answer 8

LVP Declaration:
* Prohibition: LVPs should not be declared if safeguards for Category II or III operations are not fully in place.
* Permissibility: LVPs may be declared if all safeguards are in force, regardless of the ILS category.

Equipment and Ground Services:
* Notification: Any degradation must be announced via NOTAM, ATIS, and confirmed with the pilot.
* Pilot Responsibility: The pilot must decide on the course of action and adjust minima accordingly.

Pilot Notification:
* ATC Communication: ATC should inform pilots on first contact that LVPs are in force.

Question 9

What are the actions required by ADC during ‘Low Visibility Procedures (LVPs) in Force’ for ground movement of aircraft?

Answer 9

General Caution:

• Controllers must be cautious when clearing a second aircraft to taxi if the Cat II/III holding point is not visible from the VCR (2000m distance to 25 threshold).

Traffic Information:

• Controllers must inform aircraft approaching the holding point about traffic already holding.

Stop-Bar Management:

• When a stop-bar is deselected for a departure, subsequent departures should be advised using phraseology such as:
• “Ezy123, Caution, the Alpha 2 stop-bar will be deselected for the departure ahead only. Hold at Alpha 2.”

Runway Access Clearance:

• Aircraft and vehicles must initially be cleared only to Cat II/III holding points.

IRVR Below 400m Restrictions:

• Departures should taxi only to an illuminated holding point.
• Only one aircraft can hold at a stop-bar at a time.
• Approaches should sequence arrivals with 15NM spacing.
• Movement rate (in and out) is limited to 12 per hour.

Military Pan Departures:

• Aircraft leaving the military pans south of the Tower must hold at E or F1 until an unrestricted clearance onto Charlie taxiway is possible.

Question 10

What is the requirement for holding point markings during Low Visibility Procedures (LVPs)?

Answer 10

Holding Point Compliance:
* Aircraft and vehicles must hold behind an illuminated stopbar while an aircraft is landing or taking off to comply with safeguarding requirements.

Question 11

What are the key procedures for handling arriving aircraft during Low Visibility Procedures (LVPs)?

Answer 11

Landing Clearance Timing:

• Landing clearance or go-around instructions must be given no later than 2NM from touchdown.

Infringement Restrictions:

• No aircraft or vehicle is allowed to infringe the LSA ahead of the arriving aircraft from 2NM from touchdown until the landing run is completed.

LSA Infringement Protocol:

• Landing clearance must not be issued if the LSA is known to be infringed.

Departure Clearance Coordination:

• Departing aircraft must have passed the 25 localiser aerial before an arriving aircraft reaches 2NM from touchdown.

Exception for Manual RVR Method:

• Arrivals may continue with the RVR vehicle in position at the ROP during conditions that do not preclude CAT 1 operations, with “CAT1 ONLY Operations” being promulgated.

Question 12

What are the key procedures for handling departing aircraft during Low Visibility Procedures (LVPs)?

Answer 12

Line-Up Restrictions:

• No departure shall be lined up if an arriving aircraft is less than 12NM from touchdown.

Situational Awareness Checks:

• Confirmation when the departing aircraft has passed the A2 hold.
• Confirmation when the departing aircraft has lined up.
• Confirmation when the departing aircraft has commenced its take-off run.

Take-Off Roll Timing:

• Outbound aircraft must commence its take-off roll by the time an inbound aircraft reaches 6NM from touchdown. If not, the take-off clearance will be cancelled, and the inbound aircraft will be sent around.

LSA Infringement:

• No vehicle or aircraft is allowed to infringe the LSA ahead of the departing aircraft from the time take-off clearance is issued until it is airborne.
• Take-off clearance must not be issued if the LSA ahead of the departing aircraft is known to be infringed.

Exception for Manual RVR Method:

• Departures may continue with the RVR vehicle in position at the ROP during conditions that do not preclude CAT 1 operations, with “CAT1 ONLY Operations” being promulgated.

Question 13

What are the procedures for backtracking on Runway 25 during Low Visibility Procedures (LVPs) when Taxiway Charlie and/or Taxiway Delta is out of service?

Answer 13

General Restriction:

• Backtracking on Runway 25 during LVPs is generally not permitted.

Permitted Conditions:

• 180° turns are allowed on Runway 25 if:
• The turn is visible to the controller.
• The aircraft can be seen established on the Runway 25 backtrack.

Visibility Concerns:

• If the 180° turn is not visible to the controller or there is any doubt, the aircraft must use the 07 turning circle.

Aircraft Preference:

• Code D aircraft and larger (A300/A330/B767 or larger) will prefer to use the 07 turning circle.

Question 14

What are the conditions for clearing an aircraft to enter Runway 17 from Taxiway Delta 2 when Taxiway Charlie is out of service during Low Visibility Procedures (LVPs)?

Answer 14

Visibility Requirement:

• Clearance to enter Runway 17 from D2 can only be issued if the aircraft will be continuously visible to the controller from D2 until established on Runway 17.

Follow-Me Vehicle:

• If continuous visibility cannot be achieved, clearance to enter Runway 17 cannot be issued without a follow-me vehicle.

Question 15

What are the conditions for an aircraft backtracking on Runway 25 to vacate onto Runway 35 when Taxiway Delta is out of service during Low Visibility Procedures (LVPs)?

Answer 15

Visibility Requirement:

• Aircraft may vacate left onto Runway 35 at the intersection if continuously visible to the controller during the left turn until established on Runway 35.

Alternative Taxiways:

• If continuous visibility cannot be achieved, the aircraft must vacate via Bravo or Alpha taxiway.

Question 16

What are the conditions for using Bravo holding point during Low Visibility Procedures (LVPs)?

Answer 16

No Taxiing Behind:

• Aircraft are not permitted to taxi behind an aircraft holding at Bravo.
• Aircraft are not permitted to taxi behind vehicles holding at Bravo.

Pushback Restrictions:

• Aircraft are not allowed to push back past an aircraft or vehicle holding at Bravo.

Question 17

What are the procedures for landing on Runway 17 during Low Visibility Procedures (LVPs)?

Answer 17

Landing Election:

• Pilots may elect to land on Runway 17, subject to visibility, RVR, and cloud base/ceiling values.

Backtracking Procedure:

• The landing aircraft will backtrack Runway 17 and vacate onto Taxiway Charlie.

Visibility Requirement:

• If the taxiing aircraft is not continuously visible to the ADC ATCO, the pilot must report established on the green centre line lights on Taxiway Charlie, inbound to the Apron, before the ADC ATCO issues the next landing or take-off clearance.

Uninterrupted Clearance:

• The landing aircraft must be given uninterrupted clearance to backtrack and vacate onto Taxiway Charlie to ensure the LSA remains protected.

Question 18

Which vehicles are permitted to operate within the manoeuvring area during Low Visibility Procedures (LVPs)?

Answer 18

Permitted Vehicles:

• Airport Duty Manager
• CHECKER
• Follow Me Vehicle
• External emergency vehicles (under BIAL escort)
• RFFS vehicles (including runway crossings) - RFFS should advise ATC prior to crossing if possible.
• Bird scaring vehicles (Continuous patrols withdrawn when visibility/RVR is less than 800m; periodic checks of active runway/taxiways continue)
• BIAC
• BIAL or NATS maintenance vehicles supporting LVPs

Exemptions:

• Any other vehicle must have approval from the Airport Duty Manager before entering the manoeuvring area.

Question 19

What actions are required by APC during Low Visibility Procedures (LVPs) in force?

Answer 19

Localiser Establishment:

• Aircraft must establish on the localiser at an early stage and be vectored to intercept the localiser no less than 10NM from touchdown.

Final Approach Spacing:

• Co-ordinated between ADC and RAD, with a minimum spacing of 8NM.

Freezing Fog Consideration:

• During freezing fog conditions, aircraft performing an engine run-up before departure should be considered, with recommended final approach spacing increased to 15NM.

Question 20

What are the procedures for handling practice Category II/III approaches during Low Visibility Procedures (LVPs)?

Answer 20

Discretion of ATC:

• The application of full Low Visibility Procedures for practice approaches is at the discretion of ATC based on the traffic situation both in the air and on the ground.

Pilot Notification:

• Pilots must be informed if the full procedures are not in force, such as when the checklist is not complete.

Question 21

What are the procedures for cancelling Low Visibility Procedures (LVPs), especially in unplanned situations?

Answer 21

Immediate Actions for Unplanned Cancellation:

Advise All Aircraft:
* Inform all aircraft on frequency, starting with the inbound aircraft closest to touchdown.
* Notify Approach Control:
* Advise the approach control.
* Revert to Planned Cancellation:
* Complete the checklist from the start as if it were a planned cancellation.

Clear Communication:
* Ensure all aircraft on ADC or APC frequency are clearly informed that LVPs have been cancelled.
* Confirm that EGAA is now a CAT I only operation, regardless of the stage of flight or clearance already given.
* Use a broadcast if it is unsafe to transmit directly.

Question 22

What are the steps for a planned cancellation of Low Visibility Procedures (LVPs)?

Answer 22

Initial Checks:

• Ensure no aircraft has a take-off or landing instruction.

Cancellation Procedure:

• Consult APC: Declare LVPs cancelled to all operational positions.
• Remove Strip: Remove LVPs strip from CSD.
• Update METCOM Status: Change status to either Normal or Safeguarding as appropriate.
• Inform Aircraft: Declare LVPs cancelled to all aircraft (Individual confirmation required).
• Adjust AGL Panel: Change to CAT I and adjust aircraft clearance as appropriate (e.g., Taxi to A1).
• Update ATIS Broadcast: Add “LVPs no longer in force” and transmit for at least 30 minutes.
• Annotate Watch Log: Record the cancellation in the Watch Log.

Agency Notifications:

• Advise the following that LVPs are cancelled:
• RFFS
• BIAL (request they inform ADM)
• DEO (when on duty)
• EGAA WM
• PC OS
• Additional Notifications: Mil and PSNI should also be advised.

Question 23

What are the key points regarding Low Visibility Procedures (LVPs) equipment, specifically lighting?

Answer 23

• RWY 25 ILS: Always at CAT IIIB standard unless notified otherwise by Engineering.
• Low Visibility Airfield Lighting: Operates as per AGL Panel pre-sets; all lights should be on when generators are operating.
• IRVR Lighting Input: Operates directly from the lighting control panel. Runway edge light intensity should be related to the Touchdown IRVR reading.
• Lighting Control Limitations: The “All Runway Lights” feature does not communicate with the IRVR system. Use “Pre-Set Service Selections” or “07-25 Manual Adjustment of Services” to increase lighting intensity for an IRVR reading.
• Unserviceable Touchdown Transmissometer: Use the mid-point IRVR reading.
• IRVR System Requirements: Usable readings only when edge lights are set to a brilliancy of 10% or more.
• Low-Lying Fog Alert: Controllers should be aware of conditions that may lead to low-lying fog, which is not indicated by the IRVR when brilliancy settings are below 10%.

Question 24

What are the procedures for operating standby generators during Low Visibility Procedures (LVPs)?

Answer 24

Fault Indication:

• An alarm sounds and an indication appears on the AGL panel if a fault occurs while the generators are on. Electricians must be informed.

Pulsing Lights:

• Runway edge or centerline lights may pulse when generators are selected. Rectify by changing the lighting brilliancy and reselecting the required setting. Record and report all instances of pulsing in the ADC log to the electricians.

Generator Failure:

• If a generator fails, a changeover to mains power occurs within one second. An alarm will sound, and indicators will change to reflect the switch to mains power and the generator fault. Ensure the engine stop is initiated.

Electrician Requests:

• Electricians may request generator selection for reasons indicated by a purple light in Generator Local. Generators may be switched off for servicing after running continuously for three hours.

Purpose of Standby Generators:

• Used for low visibility services and as a standby if mains power fails. Note that ‘B’ Centres lack telephone extensions.

Question 25

What actions should be taken in the event of a failure of the alternate power supply during Low Visibility Procedures (LVPs)?

Answer 25

Notify Flight Crew:
* ATC should inform flight crew on initial RTF contact.

Promulgate Information:
* Broadcast the information via ATIS when possible.

NOTAM Action:
* BIA should take appropriate NOTAM action.

Outcome:
* Flight crews will follow the appropriate instructions in their operations manual.

Question 26

What are the key points regarding the operation and management of the Instrumented Runway Visual Range (IRVR) at Belfast International Airport?

Answer 26

General Operation:

• IRVR is installed and operated according to MATS 1 Section 3 Chapter 3.
• Three sites for RWY 25/07 (touchdown, mid-point, stop-end); RWY 17 has a touchdown site only.
• IRVR direction is linked to the selected runway on the AGL panel, and readings are logged automatically.

IRVR Display Unit:

• Status can be checked via METCOM.
• Display shows “LAMPS” until direction and intensity are selected at 10% or above.
• At 10% intensity or above, displays ABV 1500 for all IRVR readings in normal conditions.
• Readings to be passed by the controller are shown in white; non-essential readings are in green.

Suspect IRVR Readings:

• Report faulty readings to the DEO immediately.
• Example: IRVR below 1000m when visibility is good.

AGL/IRVR Interface:

• If the AGL panel indicates a runway edge lighting alarm, all IRVR readings for that runway are invalid.
• Inform the DEO and seek advice on disabling affected sensors.

Unserviceabilities:

• ‘FAULT’ message replaces unserviceable IRVR readings; inform DEO immediately.
• ‘MTCE’ appears during engineering maintenance.
• DEO will issue a Class 1 NOTAM if unserviceability exceeds one hour.
• ATC can inform pilots via ATIS and R/T broadcast.

Engineering Support:

• For suspect readings or alarms, call the On-Call Engineer if unmanned. They will provide instructions or resolve the issue.
• Record all details in the ATC watch log.

Unavailability of IRVR Readings:

• Manual RVR readings by human observer are allowed for Category 1 operations only, not for Categories 2 or 3.

Question 27

What is the ‘Lower than Standard Category 1’ (LTSC1) approach and what does it require?

Answer 27

Definition:

• LTSC1 allows aircrew to fly an approach in conditions below those normally required for a CAT 1 ILS approach.
• Minima are calculated by the aircrew based on ATC information.
• The decision height remains the same as for a Category 1 ILS.

Requirements:

• LTSC1 requires the same protection and procedures as a CAT II/III approach.

Question 28

How are LTSC1 operations notified and what information is provided to flight crews?

Answer 28

Notification:

• The UK AIP informs aircrews that EGAA provides LTSC1 operations.

ATIS and Information to Flight Crews:

• In the event of an airfield outage, BIAL may declare the airfield operational but request ATC to provide specific outage information to aircrews.
• This information must be broadcast on ATIS.
• Flight crews will review the situation based on EU Ops, company, and aircraft manufacturer requirements, and adjust their minima accordingly.

Question 29

What are the requirements for an aircraft to carry out a Lower than Standard Category 1 (LTSC1) approach?

Answer 29

LVPs Must Be in Force:

• Low Visibility Procedures (LVPs) must be active.

Application of LVPs:

• ATC must apply all LVPs, including CAT II/III holds.

ILS Radiating CAT III:

• The ILS must be radiating CAT III. If not, LTSC1 approaches are not permitted and a NOTAM must be issued.

RWY 25 FFM Serviceability:

• The RWY 25 FFM must be serviceable. If unserviceable, LTSC1 approaches are not permitted and a NOTAM must be issued.

Question 30

What are the procedures for Manual Runway Visual Range (RVR) when the IRVR system is unavailable?

Answer 30

Manual RVR Usage:

• Used for Category 1 Operations when IRVR is not available.
• Not permitted for Category 2 or 3 Operations.

Manual RVR Availability:

• Provided by the RFFS (Rescue and Fire Fighting Services).

Manual RVR Points:

• 25 Touchdown
• 07 Touchdown
• 17 Touchdown
• 35 Touchdown

Procedure:

• RFFS advises ATC of the number of visible edge lights.
• ATC correlates this information with charts (Figures 29-32) to produce a manual RVR reading.
• ATC must read back the number of lights reported by RFFS.
• Requests for Manual RVRs must be made in good time to allow vehicle positioning.
• Recordings are logged on Form CA1044 and forwarded to Admin for storage upon termination of manual RVRs.

Question 31

How are RVR values disseminated and managed in the METCOM system?

Answer 31

Displaying RVR Values:

• Normally displayed on METCOM using the command format: RVR [runway] [RVR value] (e.g., RVR17 550).
• Values are displayed only when the respective runway is selected.

Communication:

• RVR values can be passed between ADC ATCO/OSS and RAD via telephone.

Clearing RVR Values:

• When the RVR value is no longer required on METCOM, it is cleared using the command: RVRX.