Difference between revisions of "Study Guide:Low Visibility Procedures"

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−
== Bedeutung ==
+
== Definition ==
  
−
LVP sind Verfahren, welche bei schlechter Sicht das Handling auf ATC-Seite eingrenzen. Der Wirkungsbereich dieser Verfahren erstreckt sich auf An- und Abflüge. Damit diese Verfahren aktiv werden können, müssen Flughafen und Flugzeug für die jeweilige CAT-Betriebsstufe freigegeben sein. Dabei ist der jeweilige tiefste Wert derjenige, welcher verwendet werden darf.  
+
Low visibility procedures exist to support Low Visibility Operations at Aerodromes when either surface visibility is sufficiently low to prejudice safe ground movement without additional procedural controls or the prevailing cloud base is sufficiently low to preclude pilots obtaining the required visual reference to continue to landing at the equivalent of an ILS Cat 1 DH/DA. [[https://www.skybrary.aero/index.php/Low_Visibility_Procedures_(LVP)]]
  
−
'''BEGRIFFE: RVR/CAT'''
+
=== Terminology: RVR/CAT ===
  
 
RVR = Runway Visual Range (Landebahnsicht)
 
RVR = Runway Visual Range (Landebahnsicht)
−
Die RVR wird pro Runway in den Abschnitten "Touchdown Zone", "Mid Point" und "Stop End" gemessen
+
 
 +
RVR is being measured at three points along the runway: "Touchdown Zone", "Mid Point" and "Stop End".
  
 
{| class="wikitable"
 
{| class="wikitable"
 
|-
 
|-
−
| ILS-Typ|| Minimale RVR || mindeste Entscheidungshöhe (über Grund)
+
| ILS-Category|| Minimum RVR || Decision Height (DH)
 
|-
 
|-
−
|Kategorie 1 / Cat I || 550 Meter oder Visibility 800 Meter || 200ft
+
|Cat I || 550 meters or visibility 800 meters || 200ft
 
|-
 
|-
−
|Kategorie 2 / Cat II || 300 Meter || 100ft
+
|Cat II || 300 meters || 100ft
 
|-
 
|-
−
|Kategorie 3a / Cat IIIa || 200 Meter || weniger als 100ft
+
|Cat IIIa || 200 meters || 100 - 0ft
 
|-
 
|-
−
|Kategorie 3b / Cat IIIb || mind. 75 Meter || weniger als 50ft
+
|Cat IIIb || 75 - 50 meters || 50 - 0ft
 
|-
 
|-
−
|Kategorie 3c / Cat IIIc || keine || keine Höhe
+
|Cat IIIc || keine RVR Begrenzung|| nil
 
|-
 
|-
 
|}
 
|}
  
−
== Verfahren ==
+
=== Terminology: Vertical Visibility ===
 +
 
 +
Vertical visibility is given in ft AGL. For LVP only BKN, OVC or VV are relevant. The latter being general vertical visibility with sufficient reduction of visibility not based on a specific cloud type. The values given in the metar are rounded down to the lowest 100ft value. OVC002 therefore means OVC between >200 and ≤300.
 +
 
 +
 
 +
 
 +
As of November 2020, in real life only RVR is considered in the decision making process whether LVP is being activated or not. This does not apply to VATSIM operations due to various factors, including but not limited to the depiction of visibility in various simulator-weather-addons.
 +
[[https://www.austrocontrol.at/jart/prj3/ac/data/dokumente/LO_Circ_2020_A_15_en_2020-10-30_1110129.pdf]]
 +
 
 +
== Decision Making Process (LOWW) ==
 +
 
 +
In order to determine whether ot not LVP has to be used, two factors have to be considered: Ceiling (lowest OVC or BKN cloud layer or vertical visibility) and RVR.
 +
 
 +
For exact criteria refer to [[#LVP Criteria For Airports|LVP Criteria For Airports]]
 +
 
 +
== Procedures ==
 +
 
 +
=== ATIS ===
 +
 
 +
Pilots need to be informed about the activity of LVP. To do this, add „&lvp“ at the end of the Uniatis-String. This will result in the following text to be recieved by the pilots:
 +
 
 +
LOW VISIBILITY PROCEDURES IN '''OPERATION'''
 +
 
 +
=== Landing Clearance ===
 +
 
 +
During LVP Landing Clearances should be given:
 +
*'''Arriving A/C 2 NM Final'''
 +
*'''In exceptional circumstances at 1 NM Final'''
 +
Note: "Should" be given - this is not a requirement per se, but rather considered as guidance for the ATCO. There is '''no''' need to inform a Pilot to expect a "late landing clearance" as this phraseology '''does not exist'''.
 +
 
 +
=== Sequencing On Final ===
 +
 
 +
Lower visibilities require enlarged separation minima on final depending on the actual conditions:
 +
 
 +
*'''CAT II radar separation on final: 4nm'''
 +
*'''CAT III radar separation on final: 6nm'''
 +
 
 +
=== Considerations For Takeoff ===
 +
 
 +
*During '''LVP Stage 2 or 3''', departing TFC should be cleared for takeoff before the next inbound for the same runway is closer that '''6nm from threshold'''.
 +
 
 +
== Phraseology ==
 +
 
 +
'''As soon as the METAR indicates an RVR value e.g: R16/P1500N you are required to transmit this value'''
 +
 
 +
In real life the controller will be provided with 3 RVR values: Touchdown Zone, Mid-Point, Stop-end.
 +
 
 +
 
 +
'''Takeoff Clearance'''
 +
 
 +
AUA94, RVR 550, 650, and 800 meters, wind 250 degrees 6 knots, RWY 29 cleared for takeoff.
 +
 
 +
 
 +
'''RVR Above maximum measurable value (1500m)'''
 +
 
 +
R16/'''P'''1500N
 +
 
 +
RVR above 1500 meters, RWY 16 Cleared for takeoff
 +
 +
The words "above" are induced by the preceeding "P" which indicates an RVR value '''ABOVE''' 1500m. (It is not possible to measure an RVR greater than 1500m)
 +
 
 +
 
 +
'''VATSIM vs. Real Life'''
 +
 
 +
As the VATSIM METAR only provides one RVR Value (Touchdown Zone RVR) you may choose to add the remaining two values at your discretion.
 +
"AUA26, 250 deg 6 kts, RVR 550, 500 and 650 Meters RWY 16 Cleared to land. </pre>
 +
 
 +
It should be noted that only dictating value is indicated in the METAR string - It defines the Touchdown Zone RVR, and thus should be used as a reference when applying the above mentioned procedure.
 +
 
 +
The same applies to Takeoff Clearances:
 +
"AUA25, 250 deg 6 kts, RVR 550, 500 and 650 Meters, RWY 29 cleared for takeoff"
 +
Or:
 +
"AUA25, 250 deg 6 kts, RVR above 1500 meters, RWY 29 cleared for takeoff"
 +
 
 +
No distinction is being made upon clearing an aircraft for an ILS approach in regard to the LVP-stage.
 +
 
 +
== LVP Criteria For Airports ==
 +
 
 +
=== LOWW ===
 +
 
 +
Available CAT III runways: 16 & 29.
 +
 
 +
==== NO LVP or CAT I ====
 +
RVR 600m or more '''AND''' ceiling 200 feet or above.
  
−
LVP in der ATIS bekanntmachen (Uniatis-String  „&LVP“)
+
==== LVP CAT II (LVP Stage 2) ====
 +
RVR less than 600m '''OR''' ceiling less than 200 feet.
  
−
CAT II: LOW VISIBILITY PROCEDURES CAT II IN OPERATION
+
==== LVP CAT III (LVP Stage 3) ====
−
CAT III: LOW VISIBILITY PROCEDURES CAT III IN OPERATION
+
LVP CAT II conditions prevail '''AND''' RVR less than 350m.
  
−
Conditional clearances mit Rücksicht auf die Verhältnisse hinterfragen
+
=== LOWL ===
−
(„do you have approaching traffic in sight?“ bei 2nm Entfernung wäre sinnlos, Taxianweisungen „follow behind … „ machen weiterhin Sinn)
+
Available CAT III runway: 26.
  
−
Landefreigabe: mind. 2,5 NM normal 3 NM in Ausnahmefällen (erfordert Info an Piloten) 1nm vor der Pistenschwelle,
+
==== NO LVP or CAT I ====
−
spätestens Intercept auf das ILS bei 8nm bis 18 NM
+
RVR 600m or more '''AND''' ceiling 200 feet or above.
  
−
Mindestabstand für APP: statt 3 NM entsprechend höher wählen (Bedenke längere Zeiten für RWY cleared etc.)
+
==== LVP CAT II (LVP Stage 2) ====
−
Piloten sind verpflichtet, „runway vacated“ zu reporten
+
RVR less than 600m '''OR''' ceiling less than 200 feet.
  
−
Im Allgemeinen wird bei solchen Sichtverhältnissen die Anflugrate drastisch reduziert.
+
==== LVP CAT III (LVP Stage 3) ====
 +
LVP CAT II conditions prevail '''AND''' RVR less than 350m.
  
−
== Phraseologie ==
+
=== LOWK ===
  
−
Anflugfreigabe durch „normale“ ILS-Freigabe aber mit Übergabe der RVR Werte:
+
Available CAT II runway 28R
  
−
Beispiel:
+
CAT III requires authorization from authority (MA-climb 4,7%)
−
''AUA 105, turn right reading 260, cleared ILS 29, RVR 500 metres''
 
  
−
Analog bei der Freigabe zur Landung.
+
==== NO LVP or CAT I ====
 +
RVR 800m or more '''AND''' ceiling 300 feet or above.
  
−
Beispiel:
+
==== LVP CAT II (LVP Stage 2) ====
−
''AUA 105, RVR 500 metres, wind 310 degrees, 9 knots, RWY 29, cleared to land'
+
N/A
−
bei initial contact Hinweis auf „LVP in operation“
 
  
−
Dem abfliegenden Luftfarhzeug muss mit der Meldung "Hold at CAT II holding point" in einem größeren Abstand von der RWY angewiesen werden.
+
==== LVP CAT III (LVP Stage 3) ====
 +
RVR less than 800m '''OR''' ceiling less than 300 feet.
  
−
== Airport-Specials ==
+
=== LOWI ===
 +
Available CAT II or CAT III runways: none.
  
−
'''LOWW'''
+
No explicit procedures for arriving traffic are published. Use best judgement and consider minima-values published on approach plates.
−
Verfügbare CAT-3 Runways 16(=Standardkonfiguration)/29
 
  
−
LVP gilt bei:
+
Also check further information in the [[LOWI_Primer]].
−
LVP WILL BECOME EFFECTIVE WHEN: RVR FOR TOCHDOWNZONE (TDZ) LESS THAN 600 M AND/OR CEILING/VERTICAL VISIBILITY LESS THAN 200FT WILL BE ACTIVATED BY RTF OR ATIS ,,LOW VISIBILITY PROCEDURES IN OPERATION”
 
−
Meldung “runway vacated” in LOWW nur auf ATC-request
 
  
−
'''LOWL'''
+
=== LOWG ===
−
Verfügbare CAT-3 Runway 26.
+
Available CAT III runways: 35C.
−
LOW VISIBILITY PROCEDURES IN FORCE FOR LOWL: ATC-LOW VISIBILITY PROCEDURES (LVP) WILL BECOME EFFECTIVE IN RELATION TO WEATHER CONDITIONS AS SPECIFIED BELOW. AVOIDANCE OF DISTURBANCES TO THE ILS SIGNALS ARE NORMALLY ACHIEVED BY PROVIDING APPROPRIATE SPACING BETWEEN AIRCRAFT ON FINAL APPROACH. LVP WILL BECOME EFFECTIVE WHEN: RVR FOR TOCHDOWNZONE (TDZ) LESS THAN 600 M AND/OR CEILING/VERTICAL VISIBILITY LESS THAN 200FT WILL BE ACTIVATED BY RTF OR ATIS ,,LOW VISIBILITY PROCEDURES IN OPERATION”
 
  
−
'''LOWK'''
+
==== NO LVP or CAT I ====
−
Verfügbare CAT-2 Runway 28R
+
RVR 600m or more '''AND''' ceiling 200 feet or above.
  
−
CAT-3 requires ATC-authorization (MA-climb 4,7%)
+
==== LVP CAT II (LVP Stage 2) ====
−
LOW VISIBILITY PROCEDURES IN FORCE FOR LOWK: ATC-LOW VISIBILITY PROCEDURES (LVP) WILL BECOME EFFECTIVE IN RELATION TO WEATHER CONDITIONS AS SPECIFIED BELOW. AVOIDANCE OF DISTURBANCES TO THE ILS SIGNALS ARE NORMALLY ACHIEVED BY PROVIDING APPROPRIATE SPACING BETWEEN AIRCRAFT ON FINAL APPROACH. LVP WILL BECOME EFFECTIVE WHEN: RVR FOR TOCHDOWNZONE (TDZ) LESS THAN 600 M AND/OR CEILING/VERTICAL VISIBILITY LESS THAN 200FT WILL BE ACTIVATED BY RTF OR ATIS ,,LOW VISIBILITY PROCEDURES IN OPERATION”
+
RVR less than 600m '''OR''' ceiling less than 200 feet.
  
−
'''LOWI'''
+
==== LVP CAT III (LVP Stage 3) ====
−
Verfügbare CAT-2 oder CAT-3 Runway: keine. Es gibt auch keine definierten LVP, aber folgende Minima:
+
LVP CAT II conditions prevail '''AND''' RVR less than 350m.
−
* VFR minima: dem Luftraum (Cat. B) entsprechend
 
−
* IFR arrival minima: 3km (aircraft cat. A-B) bzw. 5km (Aircraft cat. C-D) flight visibility
 
−
* IFR departure minima: 1.500m,
 
−
*: - except RNAV 0.3 RNP departure: RVR 300m.
 
−
*: - except low fog or mist: RVR 600m AND visibility >5km above this layer AND no further clouds 3.100ft AAL
 
  
−
Mehr Infos zu Innsbruck Minima im [[LOWI_Primer]].
+
=== LOWS ===
 +
Available CAT II runway: 16.
  
−
'''LOWG'''
+
CAT III requires authorization (see special chart)
−
Verfügbare CAT-3 Runway 35C
 
  
−
LOW VISIBILITY PROCEDURES IN FORCE FOR LOWG: ATC-LOW VISIBILITY PROCEDURES (LVP) WILL BECOME EFFECTIVE IN RELATION TO WEATHER CONDITIONS AS SPECIFIED BELOW. AVOIDANCE OF DISTURBANCES TO THE ILS SIGNALS ARE NORMALLY ACHIEVED BY PROVIDING APPROPRIATE SPACING BETWEEN AIRCRAFT ON FINAL APPROACH. LVP WILL BECOME EFFECTIVE WHEN: RVR FOR TOCHDOWNZONE (TDZ) LESS THAN 600 M AND/OR CEILING/VERTICAL VISIBILITY LESS THAN 200FT WILL BE ACTIVATED BY RTF OR ATIS ,,LOW VISIBILITY PROCEDURES IN OPERATION”
+
==== NO LVP or CAT I ====
 +
Visibility and RVR 1500m or more '''AND''' ceiling 600 feet or above.
  
−
'''LOWS'''
+
==== LVP CAT III (LVP Stage 2) ====
−
Verfügbare CAT-2 Runway 16
+
N/A
  
−
CAT-3 requires ATC-authorization (see special chart)
+
==== LVP CAT III (LVP Stage 3) ====
 +
Visibility or RVR less than 1500m '''OR''' ceiling less than 600 feet.
  
 
[[Category:Documents]][[Category:Study Guides]][[Category:Procedures]][[Category:Training]][[Category:Controller]]
 
[[Category:Documents]][[Category:Study Guides]][[Category:Procedures]][[Category:Training]][[Category:Controller]]

Latest revision as of 11:20, 20 February 2021

Definition

Low visibility procedures exist to support Low Visibility Operations at Aerodromes when either surface visibility is sufficiently low to prejudice safe ground movement without additional procedural controls or the prevailing cloud base is sufficiently low to preclude pilots obtaining the required visual reference to continue to landing at the equivalent of an ILS Cat 1 DH/DA. [[1]]

Terminology: RVR/CAT

RVR = Runway Visual Range (Landebahnsicht)

RVR is being measured at three points along the runway: "Touchdown Zone", "Mid Point" and "Stop End".

ILS-Category Minimum RVR Decision Height (DH)
Cat I 550 meters or visibility 800 meters 200ft
Cat II 300 meters 100ft
Cat IIIa 200 meters 100 - 0ft
Cat IIIb 75 - 50 meters 50 - 0ft
Cat IIIc keine RVR Begrenzung nil

Terminology: Vertical Visibility

Vertical visibility is given in ft AGL. For LVP only BKN, OVC or VV are relevant. The latter being general vertical visibility with sufficient reduction of visibility not based on a specific cloud type. The values given in the metar are rounded down to the lowest 100ft value. OVC002 therefore means OVC between >200 and ≤300.


As of November 2020, in real life only RVR is considered in the decision making process whether LVP is being activated or not. This does not apply to VATSIM operations due to various factors, including but not limited to the depiction of visibility in various simulator-weather-addons. [[2]]

Decision Making Process (LOWW)

In order to determine whether ot not LVP has to be used, two factors have to be considered: Ceiling (lowest OVC or BKN cloud layer or vertical visibility) and RVR.

For exact criteria refer to LVP Criteria For Airports

Procedures

ATIS

Pilots need to be informed about the activity of LVP. To do this, add „&lvp“ at the end of the Uniatis-String. This will result in the following text to be recieved by the pilots: 

LOW VISIBILITY PROCEDURES IN OPERATION

Landing Clearance

During LVP Landing Clearances should be given:

  • Arriving A/C 2 NM Final
  • In exceptional circumstances at 1 NM Final

Note: "Should" be given - this is not a requirement per se, but rather considered as guidance for the ATCO. There is no need to inform a Pilot to expect a "late landing clearance" as this phraseology does not exist.

Sequencing On Final

Lower visibilities require enlarged separation minima on final depending on the actual conditions:

  • CAT II radar separation on final: 4nm
  • CAT III radar separation on final: 6nm

Considerations For Takeoff

  • During LVP Stage 2 or 3, departing TFC should be cleared for takeoff before the next inbound for the same runway is closer that 6nm from threshold.

Phraseology

As soon as the METAR indicates an RVR value e.g: R16/P1500N you are required to transmit this value

In real life the controller will be provided with 3 RVR values: Touchdown Zone, Mid-Point, Stop-end.


Takeoff Clearance 

AUA94, RVR 550, 650, and 800 meters, wind 250 degrees 6 knots, RWY 29 cleared for takeoff.


RVR Above maximum measurable value (1500m)

R16/P1500N 

RVR above 1500 meters, RWY 16 Cleared for takeoff

The words "above" are induced by the preceeding "P" which indicates an RVR value ABOVE 1500m. (It is not possible to measure an RVR greater than 1500m)


VATSIM vs. Real Life

As the VATSIM METAR only provides one RVR Value (Touchdown Zone RVR) you may choose to add the remaining two values at your discretion.

"AUA26, 250 deg 6 kts, RVR 550, 500 and 650 Meters RWY 16 Cleared to land.

It should be noted that only dictating value is indicated in the METAR string - It defines the Touchdown Zone RVR, and thus should be used as a reference when applying the above mentioned procedure.

The same applies to Takeoff Clearances: 

"AUA25, 250 deg 6 kts, RVR 550, 500 and 650 Meters, RWY 29 cleared for takeoff"

Or: 

"AUA25, 250 deg 6 kts, RVR above 1500 meters, RWY 29 cleared for takeoff"

No distinction is being made upon clearing an aircraft for an ILS approach in regard to the LVP-stage.

LVP Criteria For Airports

LOWW

Available CAT III runways: 16 & 29.

NO LVP or CAT I

RVR 600m or more AND ceiling 200 feet or above.

LVP CAT II (LVP Stage 2)

RVR less than 600m OR ceiling less than 200 feet.

LVP CAT III (LVP Stage 3)

LVP CAT II conditions prevail AND RVR less than 350m.

LOWL

Available CAT III runway: 26.

NO LVP or CAT I

RVR 600m or more AND ceiling 200 feet or above.

LVP CAT II (LVP Stage 2)

RVR less than 600m OR ceiling less than 200 feet.

LVP CAT III (LVP Stage 3)

LVP CAT II conditions prevail AND RVR less than 350m.

LOWK

Available CAT II runway 28R

CAT III requires authorization from authority (MA-climb 4,7%)

NO LVP or CAT I

RVR 800m or more AND ceiling 300 feet or above.

LVP CAT II (LVP Stage 2)

N/A

LVP CAT III (LVP Stage 3)

RVR less than 800m OR ceiling less than 300 feet.

LOWI

Available CAT II or CAT III runways: none.

No explicit procedures for arriving traffic are published. Use best judgement and consider minima-values published on approach plates.

Also check further information in the LOWI_Primer.

LOWG

Available CAT III runways: 35C.

NO LVP or CAT I

RVR 600m or more AND ceiling 200 feet or above.

LVP CAT II (LVP Stage 2)

RVR less than 600m OR ceiling less than 200 feet.

LVP CAT III (LVP Stage 3)

LVP CAT II conditions prevail AND RVR less than 350m.

LOWS

Available CAT II runway: 16.

CAT III requires authorization (see special chart)

NO LVP or CAT I

Visibility and RVR 1500m or more AND ceiling 600 feet or above.

LVP CAT III (LVP Stage 2)

N/A

LVP CAT III (LVP Stage 3)

Visibility or RVR less than 1500m OR ceiling less than 600 feet.

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