VACC Austria DokuWiki - User contributions [en]

Study Guide: Approach

2014-01-12T10:01:49Z

Frederic Gierlinger: Added back and forward link as in the other study guides

'' Prev: [[Study Guide:Tower]] - Overview: [[Study Guide]] - Next: [[Study Guide:Radar]]''

= General =

TMA controller includes approach and departure control services associated with a particular airport have the following main tasks:

#maintain an orderly flow of traffic
#provide separation service between aircraft
#provide assistance to pilots 

----

= General radar procedures =

==== Identifikation mit Hilfe eines Transponders ====

Ein Transponder ist ein Bauteil von den gängigen Verkehrs- und Sportflugzeugen, es dient zur Übermittlung von Daten an die Flugverkehrskontrollstelle um die Flugsicherung zu vereinfachen. Mit Hilfe des Transponders ist es möglich, einem Kontakt auf dem Primärradar ein Callsign und einen Flugplan zu zuordnen. Aus diesem Grund erhält jeder Instrumentenflug und spezielle VFR Verfahren von der Flugverkehrskontrollstelle einen Transpondercode zugewiesen.

===== Mode A =====

Flugzeuge mit Transpondermode A senden nur den zugewiesenen Transpondercode.

===== Mode C =====

Flugzeuge mit Transpondermode C sind in der Lage neben dem Transpondercode auch die aktuelle Flughöhe, gemessen vom barometrischen Höhenmesser. Die übermittelte Höhe ist unabhängig vom eingestellten QNH, die Übermittlung erfolgt in 100-Fuß-Schritten.

===== Mode S =====

Transpondermode S übermittelt neben dem Squawk und der Flughöhe zusätzlich das Callsign des Flugzeugs.

----

=== Position informations ===

Positionsinformationen dienen zur Orientierung des Piloten und können nach Möglichkeit an Hand von Navaids oder markanten Punkten, ähnlich den Pflichtmeldepunkten an den Piloten übermittelt werden. Die Positionsinformation unter Angabe markanter Punkte soll nur reaktiv angeboten werden, nicht jeder Pilot unter IFR ist mit den Örtlichkeiten vertraut, es empfiehlt sich daher grundsätzlich veröffentlichte Navaids oder einfache Kursangaben und Entfernung für die Übermittlung solcher Informationen zu nutzen. 

----

=== Vectoring of Aircrafts ===

Flugzeuge kann man mit Hilfe von Kursanweisungen in die gewünschte Flugrichtung führen. Es ist dabei zu beachten, dass eine Kursanweisungen zu einem gewünschten Punkt in Abhängigkeit von Wind, Geschwindigkeit und Bank-Angle nicht immer 100%ig zum gewünschten Ergebnis führen kann, darum ist es wichtig, ein gewisses Gefühl für die Piloten und Flugzeuge zu entwickeln. Übrigens, bei einem Bank Angle von 30° und identischer Geschwindigkeit, ist der Kurvenradius eines Airbus A380 genau so groß, wie der einer Cessna Citation, obwohl diese viel kleiner ist. Grundsätzlich empfiehlt sich, Kursanweisungen möglichst großzügig und rechtzeitig zu erteilen und ein Flugzeug lieber bei 12 dme until touchdown auf dem LOC aufzufädeln, als auf 8 dme.

----

=== Usage of directs ===

Piloten unter RNAV und Non-RNAV sind neben dem befolgen von Kursanweisungen auch in der Lage, ihr Flugzeug direkt zu einem gewünschten Wegpunkt zu navigieren und anschließend auf der ursprünglich geplanten Route weiterzufliegen. Die Anweisung zum fliegen eines directs ist für den Piloten nicht verbindlich, er darf dies jederzeit ohne Angabe von Gründen ablehnen. In Absprache mit benachbarten Flugverkehrskontrollstellen ist es auch möglich, directs über große Entfernungen und durch mehrere Flugsicherungssektoren anzubieten. Bei der Freigabe für den Direktflug zu einem Wegpunkt ist zu prüfen, ob der Pilot davon überhaupt einen Nutzen hat, ein Shortcut welcher den Flugweg des Flugzeugs lediglich um 2 Meilen verkürzt ist kein direct und keine Hilfe für den Piloten. Bei der Vergabe von Shortcuts besteht die Gefahr, dass man sich selbst sehr schnell den Luftraum zusperrt, besonders auf Flughäfen wie Innsbruck ist es riskant allen Flugzeugen den Direktflug zum IAF (RTT bzw. KTI NDB) zu erteilen. Ein Direct zu einen Punkt auf einer Transition ist übrigens die gleichzeitige Freigabe für die gesamte darauffolgende Wegstrecke der Transition, allerdings nicht des vertikalen Profils, gleiches gilt für einen Direct zu einem Punkt der STAR, so ist der Pilot freigegeben für die gesamte STAR bis zum IAF, nicht mehr nur bis zum clearance limit. 

----

= Separation =

=== Vertical separation ===

Vertical separation is obtained by requiring aircraft using prescribed altimeter setting procedures to operate at different levels to avoid lost of separation. The vertical separation minimum shall be 1000 feet below FL 410 in RVSM airspace or 2000 feet above FL290 in non-RVSM airspaces. To fly within RVSM an aircraft must be equipped with:

#2 independent altimeters
#an autopilot witch must be able to hold an specific altitude
#min. Mode C transponder

----

=== Lateral separation ===

Lateral separation is also known as radar separation and shall be applied so that the distance between those portions of the intended routes for with the aircraft are to be laterally separated is never less than an established distance to account for navigational inaccuracies. Have a look into the wake turbulence separation to find the required distances for the lateral separation.

----

=== Wake turbulence separation ===

Wake turbulence is turbulence that forms behind an aircraft as it passes through the air. This turbulence includes various components, the most important of which are wingtip vortices and jetwash. Jetwash refers simply to the rapidly moving gases expelled from a jet engine; it is extremely turbulent, but of short duration. Wingtip vortices, on the other hand, are much more stable and can remain in the air for up to three minutes after the passage of an aircraft.

===== Takeoff =====

An aircraft of a lower wake vortex category must not be allowed to take off less than two minutes behind an aircraft of a higher wake vortex category. If the following aircraft does not start its take off roll from the same point as the preceding aircraft, this is increased to three minutes.

===== Landing =====

{| style="width: 415px; height: 256px;" class="wikitable"
|-
! Preceding aircraft
! Following aircraft
! Minimum radar separation
|-
| rowspan="4" | Super
| Super
| 4 [[Nautical mile|NM]]
|-
| Heavy
| 6 NM
|-
| Large
| 7 NM
|-
| Small
| 8 NM
|-
| rowspan="3" | Heavy
| Heavy
| 4 NM
|-
| Large
| 5 NM
|-
| Small
| 5 NM
|-
| Large
| Small
|
4 NM

|}

*Staying on or above leader's glide path Incident data shows that the greatest potential for a wake vortex incident occurs when a light aircraft is turning from base to final behind a heavy aircraft flying a straight-in approach. Light aircraft pilots must use extreme caution and intercept their final approach path above or well behind the heavier aircraft's path. When a visual approach following a preceding aircraft is issued and accepted, the pilot is required to establish a safe landing interval behind the aircraft he was instructed to follow. The pilot is responsible for wake turbulence separation. Pilots must not decrease the separation that existed when the visual approach was issued unless they can remain on or above the flight path of the preceding aircraft. 

----

=== Separation with individual speeds ===

A controller may issue speed instructions within an aircraft operating limits. There are two possible ways to do this, either by using Indicated Airspeed (FL280 or below) or by specifying a Mach number (FL280 or above). Take notice of the minimum speed of the aircraft! Normally you are working with "minimum clean" (means the lowest speed an aircraft can maintain without using flaps or slats above FL100. The best way to gain separation between two aircraft is to advise an specific speed to the relevant aircraft.

For example:
<pre>LOWW_APP: AUA14F, speed 220 knots indicated.
AUA14F: Speed 220 Knots, AUA14F.
</pre>
If the pilot reports "unable" ask the pilot witch speed would be suitable for his current situation. Its important to know that aircraft like a Boeing 747 with a lot of payload on an long distance leg are unable to stay below 250 knots during departure.

*'''The phrase "<strike>Reduce to minimum approach speed</strike>" shall not be used!'''

----

= Phraseology =

A ...Pilot G...ATC 

==== Approach ====

Standard clearances for arriving aircraft shall contain the following items, if applicable: 

1. Aircraft identification 2. Designator of assigned STAR 3. Runway-in-use, except when part of the STAR description 4. Initial level, except when this element is included in the START description and 5. Any other necessary instructions or information not contained in the START description, e.g. change of communication 

==== Type of approach procedure ====

G: CLEARED / PROCEED VIA (designator) ARRIVAL G: CLEARED TO (clearance limit) VIA (designator) ARRIVAL G: CLEARED (type of approach) APPROACH RUNWAY (number) G: CLEARED LOCALIZER APPROACH [RUNWAY (number)] [GLIDE PATH INOPERATIVE] G: CLEARED APPROACH RUNWAY (number) A: REQUEST (type of approach) APPROACH [RUNWAY (number)] G: (type of approach) NOT AVAILABLE DUE (reason) [alternative instructions] A: REQUEST (RNAV plain language designator) G: CLEARED (RNAV plain language designator) G: ARE YOU FAMILIAR WITH (name) APPROACH PROCEDURE [RUNWAY (number)]?

==== Straight-in approach ====

A: REQUEST STRAIGHT-IN / DIRECT [type of approach] APPROACH [RUNWAY (number)] G: CLEARED STRAIGHT-IN / DIRECT [type of approach] APPROACH [RUNWAY (number)] 

==== Approach instructions with radar ====

G: VECTORING FOR (tpye of pilot interpreted aid) APPROACH RUNWAY (number) G: VETORING FOR VISUAL APPROACH RUNWAY (number), REPORT FIELD / RUNWAY IN SIGHT G: VECTORING FOR (positioning in the circuit) G: VECTORING FOR SURVEILLANCE RADAR APPROACH RUNWAY (number) G: VECTORING FOR PRECISION APPROACH RUNWAY (number) G: (type) APPROACH NOT AVAILABLE DUE (reason) (alternative instructions) G: POSITION (number) MILES FROM (position) / TOUCH DOWN. TURN LEFT / RIGHT HEADING (three digits) G: YOU WILL INTERCEPT (radio aid or track) (distance) FROM (significant point) / TOUCH DOWN A: REQUEST (distance) FINAL G: CLEARED FOR (type) APPROCH RUNWAY (number) G: REPORT ESABLISHED [ON ILS / LOCALIZER / GLIDE PATH] G: REPORT ESTABLISHED ON FINAL APPROACH TRACK G: CLOSING FROM LEFT / RIGHT [REPORT ESTABLISHED] G: TURN LEFT / RIGHT HEADING (three digits) [TO INTERCEPT [RIGHT TO LEFT / LEFT TO RIGHT / REPORT ESTABLISHED] G: EXPECT VECTORS ACROSS (localizer or radio aid) (reason) G: THIS TURN WILL TAKE YOU THROUGH (localizer or radio aid) [reason] G: TAKING YOU THROUGH (localizer or radio aid) [reason] G: MAINTAIN (altitude) UNTIL GLIDE PATH INTERCEPTION G: REPORT ESTABLISHED ON GLIDE PATH G: INTERCEPT (localizer or radio aid) [REPORT ESTABLISHED] G: INTERCEPT (radio aid) [LEFT TO RIGHT / RIGHT TO LEFT] G: CLEARED FOR ILS APPROACH RUNWAY (number) LEFT / RIGHT G: YOU HAVE CROSSED THE LOCALIZER. TURN LEFT / RIGHT IMMEDIATELY AND RETURN TO THE LOCALIZER G: ILS RUNWAY (number) LEFT / RIGHT LOCALIZER FREQUENCY IS (number) G: TURN LEFT / RIGHT (number) DEGREES / HEADING (three digits) IMMEDIATELY TO AVOID TRAFFIC [DEVIATING FROM ADJACENT APPROACH], CLIMB TO (level) G: CLIMB TO (level) IMMEDIATELY TO AVOID TRAFFIC [DEVIATING FROM ADJACENT APPORACH] (further instructions) 

 

==== Go around ====

G: GO AROUND IMMEDIATELY (missed approach instruction) (reason) G: IF GOING AROUND (appropriate instructions) G: ARE YOU GOING AROUND? A: GOING AROUND 

==== Level changes, reports and rates ====

G: CLIMB / DESCEND - TO (level) - TO AND MAINTAIN BLOCK (level) TO (level) - TO REACH (level) AT / BY (time or significant point) - REPORT LEAVING / REACHING / PASSING (level) - AT (number) FEET PER MINUTE [OR GREATER / LESS] G: REQUEST LEVEL / FLIGHT LEVEL / ALTITUDE CHANGE FROM (name of level) [AT (time or significant point)] G: STOP CLIMB / DESCENT AT (level) G: CONTINUE CLIMB / DESCENT TO (level) G: EXPEDITE CLIMB / DESCEND [UNTIL PASSING (level)] G: RESUME NORMAL RATE OF CLIMB / DESCENT G: REPORT LEAVING / REACHING / PASSING (level) G: WHEN READY CLIMB / DESCENT TO (level) G: EXPEDITE CLIMB / DESCENT AT (time of significant point) G: EXPEDITE CLIMB / DESCENT UNTIL PASSING (level) A: REQUEST DESCENT AT (time) A: REQUEST ALTITUDE (number FEET) / FLIGHT LEVEL (number) VIA (route) [DUE TO (reason)] A: REQUEST LEVEL CHANGE / CLIMB / DESCENT AT (time / position) G: EXPECT LEVEL CHANGE / CLIMB / DESCENT - FROM (name of unit) - AT (time or position) - AFTER PASSING (position) - IN (number) MINUTES G: IMMEDIATELY G: AFTER PASSING (significant point) G: AT (time or significant point) G: WHEN READY (instructions) 

==== Vectoring ====

G. LEAVE (significant point) HEADING (three digits) [INBOUND [AT (time)] G: CONTINUE HEADING (three digits) G: CONTINUE PRESENT HEADING G: FLY HEADING (three digits) G: TURN LEFT / RIGHT HEADING (three digits) [reason] G: TURN LEFT / RIGHT (number) DEGREES [reason] G: STOP TURN HEADING (three digits) G: FLY HEADING (three digits), WHEN ABLE PROCEED DIRECT (name) (significant point) G: HEADING IS GOOD G: WHEN ABLE PROCEED DIRECT (position) G: SUGGEST (suggestion) G: IF UNABLE [(alternative instructions)] ADVISE A: UNABLE TO COMPLY (reason) G: VECTORING FOR SPACING / SEPERATION / DELAY G: VECTORING DUE TO TRAFFIC G: RESUME OWN NAVIGATION (position of a/c) (specific instructions) G: RESUME OWN NAVIGATION [DIRECT] (significant point) [MAGNETIC TRACK (three digits) DISTANCE (number) MILES] G: MAKE A THREE SIXTY TURN LEFT / RIGHT [reason] G: ORBIT LEFT / RIGHT [reason] G: MAKE ALL TURNS RATE ONE / RATE HALF (number) DEGREES PER SECOND START AND STOP ALL TURNS ON THE COMMAND “NOW” G: ALL TURNS RATE ONE / RATE HALF (number) DEGREES PER SECOND, EXECUTE ISNTRUCTIONS IMMEDIATELY UPON RECEIPT G: TURN LEFT / RIGHT NOW G: STOP TURN NOW 

==== Speed instructions: ====

G: REPORT SPEED G: REPORT INDICATED AIRSPEED / TRUE AIRSPEED / MACH NUMBER A: SPEED (number) KNOTS / MACH (number) G: MAINTAIN (number) KNOTS / MACH (number) [OR GREATER / LESS] [UNTIL (significant point)] G: DO NOT EXCEED (number) KNOTS / MACH (number) G: MAINTAIN PRESENT SPEED G: INCREASE / REDUCE SPEED (number) KNOTS / MACH (number) [OR GREATER / LESS] G: INCREASE / REDUCE SPEED BY (number) KNOTS / MACH (number) [OR GREATER / LESS] A: UNABLE TO COMPLY, INDICATED AIRSPEED WILL BE (number) KNOTS / MACH (number) G: RESUME NORMAL SPEED G: REDUCE TO MINIMUM APPROACH SPEED G: REDUCE TO MINIMUM CLEAN SPEED G: REDUCE TO MINUMUM SPEED A: MINUMUM SPEED / MINIMUM CLEAN SPEED / MINIMUM APPROACH SPEED IS (number) KNOTS G: NO [ATC] SPEED RESTRICTIONS 

==== Flight rules ====

A: CANCELLING IFR G: IFR CANCELLED AT (time)

A: REQUEST IFR CLEARANCE G: CLEARED TO (clearance limit), VIA (route) (level) (other instructions), IFR [FLIGHT] STARTS AT (position or time) / WHEN REACHING (level) / PASSING (level) / NOW [(instructions)]

G: CLEARED NIGHT VFR G: CLEARED SPECIAL VFR 

= FAQs =

'''How do I work with STARs and Transitions?''' STAR means ''Standard Terminal Arrival Route'' is like a route to the airport.This road has a name that has three parts. The first part is the navigational point where the route starts, the second is the version number, and the third is usually but again not always coupled to a certain runway(s). Transitions are connecting between the end of STAR to the final but not at any airport. Using STARs and Transition simplifies the arrival considerably for both pilots and controllers. By clearing "transition and profile" the pilot has also the clearance for descending as published. So you can expect the track, descend and speed of an aircraft as published. 

'''How to use a Holding?''' The primary use of a holding is delaying aircraft that have arrived over their destination but cannot land yet because of traffic congestion, poor weather, or unavailability of the runway. Several aircraft may fly the same holding pattern at the same time, separated vertically by 1,000 feet or more. A holding is situated around a holding fix. In a standard holding pattern the aircraft flies inbound to the holding fix on a certain course (Inbound leg). After passing the fix it turns right (standard turn: 2° per second) and flies one minute (1,5 min above FL 140) into the other direction (outbound leg). After one minute the pilot turns right again (standard turn) and establishes again on the inbound leg. If you count all this together you end up with four minutes required to finish one holding pattern. However some holding patterns use left turns, others don't use one minute to measure the outbound leg, but fly to a certain distance. Also every holding has a minimum altitude.

 

'''What does MRVA mean?''' '''M'''inimum '''R'''adar '''V'''ectoring '''A'''ltitude: lowest altitude above MSL that can be used for IFR vectoring 

 

'''When is the best moment for my handoff?''' Out of conflict and as early as possible. 

 

'''Which classes of airspace are provided in Austria?'''

*C (Charlie) controlled airspace, IFR and VFR possible, aircontroll is mandatory. IFR will be separated to other IFR and VFR traffic, VFR traffic receive traffic information about other VFR traffic. C starts AT FL195 and inside Special Rules Area (e.g. SRA Wien) 
*D (Delta) controlled airspace, IFR and VFR possible, aircontroll is mandatory. IFR is separated to other IFR and receives traffic information about other VFR; VFR traffic reveives information about other traffic. D in Austria covers space between FL125 and FL195 (CTA) and inside contolled zones and certain SRA.
*E (Echo) controlled airspace only for IFR; VFR receives information as far as possible. In Austria up to FL125 in inside of certain TCAs ('''T'''erminal '''C'''ontrol '''A'''reas).
*G (Golf) uncontrolled airspace. Traffic information as far as possible. 

'''What are Y and Z-flights?''' Basically these are flights with a change between IFR/VFR 

*Y starts with IFR, changing to VFR (IFR cancellation)

*Z starts with VFR, changing to IFR (IFR pickup)

 

= References =

Information about airspaces and airways can be found here: [http://www.vateud.net/index.php?option=com_content&view=article&id=127&Itemid=205]

Details about air pressure and altitudes you will find here: [http://www.vateud.net/index.php?option=com_content&view=article&id=126&Itemid=201]

Links for the reference (working) sheets you find at the airport details. 

 

 

= Local Procedures =

== LOWW ==

Frequencies: (called Wien Radar)

128.200 Wien Approach 119.800 Wien Director 124.550 Wien Nord Approach 129.050 Wien South Approach

'''Limits'''

- vertikal: GND - FL245

'''preferred RWY configurations'''

- ARR 34/DEP 29 
- ARR 11+16/DEP 16 
- ARR 16/DEP 16+29 

 reference sheet you find [http://downloads.vacc-austria.org/Documents/QRS_LOWW_v1.3.pdf downloads.vacc-austria.org/Documents/QRS_LOWW_v1.3.pdf]

== LOWI ==

Frequencies: 119.27

Transition Altitude: 11000ft

'''Limits'''

- vertikal: GND - FL165

'''Arrivals'''

*LOC/DME West via KTI FL130 over KTI

*LOC//DME East via RTT 9500ft over RTT

*RNP – RNAV Approach Runway 26: instrumental approach with lower minimas, final also a visual approach. Only on pilot request; different miss-appproach-procedure

*All arrivals are going via AB, finals after AB are always visual

The reference sheet you find: [http://downloads.vacc-austria.org/Documents/QRS_LOWI_v1.2.pdf downloads.vacc-austria.org/Documents/QRS_LOWI_v1.2.pdf]

== LOWG ==

Frequencies: 119.3

Transition Altitude: 4000ft

'''Limits'''

- vertikal: GND - FL165

'''Arrivals''' There are no STARs in LOWG. Most of the arrival routes ends at GRZ-VOR. After GRAZ normally vectors are used.

*ILS 35C starts at 3300ft. Best way is to intercept at LENIZ at 3500ft.

*VOR-DME 35C: Approach über GRZ-VOR nach DME 7.0 GRZ (heading 147°), danach vector auf final track

*VOR-DME 17C: Approach über GRZ-VOR, starts at D15. GRZ 7000ft, descend profile see chart.

'''hand/over'''

*LHCC_CTR via GOTAR FL150

*LJLA_CTR via RADLY FL160

*LOVV_CTR FL160

== LOWK ==

Frequencies: 126.825

Transition Altitude: 7000ft

'''Limits'''

- vertikal: GND - FL165

'''Arrivals'''

*ILS 28

*NDB-DME 28

*NDB-DME 10

*Circling 10: Anflug über ILS28, desc. 3000ft, circeling starts at KI

'''hand/over'''

*LJLA_CTR via REKTI FL160

*LOVV_CTR FL160

== LOWS ==

Frequencies: 123.720 Transition Altitude: 4000ft

Limits

- vertikal: GND - FL125

Arrivals

ILS 16 NDB 16  visual 34 hand/over

EDDM_S_APP via NAPSA and TRAUN EDDM_CTR via TRAUN rest to LOVV_CTR, all FL120 

reference sheet you find at [http://downloads.vacc-austria.org/Documents/QRS_LOWS_v1.1.pdf downloads.vacc-austria.org/Documents/QRS_LOWS_v1.1.pdf]

 

== LOWL ==

Frequencies: 129.620 Transition Altitude: 4000ft

Limits

- vertikal: GND - FL165

Arrivals

ILS/VOR 08 (ILS 08 not in standard FSX)  ILS/NDB 26 (former RWYs known as 09 and 27)

hand/over

EDDM_CTR via PABSA and TRAUN LKAA_CTR via ADLET rest to LOVV_CTR, all FL160

 reference sheet you find at [http://downloads.vacc-austria.org/Documents/QRS_LOWL_v1.0.pdf downloads.vacc-austria.org/Documents/QRS_LOWL_v1.0.pdf]

==References==

* http://en.wikipedia.org/wiki/Wake_turbulence 

* The VACC-SAG.org study guide for APP is more detailed and well to read: see [[http://board.vacc-sag.org/14/23543/ this thread]] in the VACC-SAG board (you need a login, and it's free).

* The Austrocontrol [[http://eaip.austrocontrol.at/lo/130110/PART_2/LO_ENR_1_4_en.pdf airspace definition]]

[[Category:Documents]] [[Category:Study_Guides]] [[Category:Training]] [[Category:Controller]]

Study Guide:Ground

2014-01-12T09:51:42Z

Frederic Gierlinger: typo

'' Prev: [[Study Guide:Delivery]] - Overview: [[Study Guide]] - Next: [[Study Guide:Tower]]''

= General =

Ground is responsible for all movements of aircraft on ground, except the movements on the runway. Ground takes over responsibility for Delivery if he is not online. 

Your responsibility is strict: if you allow a plane to do something, the pilot can do without looking either way - you have to be sure the way is clear. This is, because big aircraft neither have a 360° view nor rear mirrors like a car has.
----

=== Phraseology ===

==== Start-up clearance ====

Start-up clearance can be given if no other aircraft is taxiing behind the starting-up aircraft and if the take-off is expected in 20 minutes or less. 

Austrian 125, start-up approved, (Temperature Minus 3)

==== Push-back clearance ====

Push-back clearance can be given if no other aircraft is passing behind and the parking position requires push-back. 

Austrian 125, push-back approved

Push-back is an ''approval'' - pilots are free to do it whenever they are ready. This means: It could take a while. This means: In busy conditions, you won't want that, as there is an aircraft which can push out any time and you cannot allow any other aircraft taxi behind. Several options are available to solve this problem:

Austrian 125, immediate push-back approved.

(the pilot has to say "unable" if he still programs the FMC)

Austrian 125, startup approved, call for push with running engines

(the pilot is ready for push and won't stand around on the taxiway trying to light his engines)

==== '''Combination of both phrases''' ====

During low traffic you can use these two phrases together 

Austrian 125, start(-up) and push(-back) approved

==== Taxi Instructions ====

Bear in mind: Taxi instructions are '''clearances''', that means: The pilot must and will do it regardless of other things - mainly aircraft around. Don't clear anyone for taxiing around without knowing that the way is free. Aircraft won't stop at junctions and look left or right (in most cases, they can't as they won't see enough).

The sequence is: The pilot pushes back and starts the aircrafts engines. As soon as he is ready for taxi he will call you:

AUA125:AUA125, ready for taxi.

Depending on traffic you can give him the taxi instruction to his departure runway:

GND:AUA125, taxi to holding point Rwy 16 via taxiways Exit 4, L and F, QNH 1019.
AUA125:Taxiing to holding point runway 29 via L and F, AUA125.

So how do you maintain traffic flow at a busy airport, but still maintaining safety? There is some options:

First is to clear the aircraft just as far as the way is free: "taxi to exit 32". "Taxi on E until intersection B4", and the like. But this is time-consuming, you loose overview, you forget aircraft on the way (they wait around for nothing), and it is slow too.

Second, and more elegant is the '''hold short''' argument:

GND:AUA125, hold short of taxiway L.
AUA125:Holding short of L, AUA125.

This means: The aircraft is cleared all the way to the holding point, but has to "hold short" (=to stop) in mid way '''for a condition which you specify'''. After that (that's the elegant part), he continues as cleared without further instructions.

* This could be only to "hold short" --> until you tell him "continue".
* It could be "give way to crossing B737 from your left to your right" --> the pilot will stop, wait for a passing 737 and continue.
* It could be "follow company B737 taxiing on L" --> the pilot will look out for a B737 of his own color and follow him.
* It could be anything else, provided that the pilot is able to do it, like 1 minute or whatever.

The "Hold short" argument puts some '''burden on the pilot''': He must judge if he can meet the condition. If you tell a B747 to follow a C172, he might likely say "unable", as he is simply unable to see the little fly under his nose. As a controller, it is no good idea to tell pilots something they can't do (i.e. look behind) - pilots might oversee it and - bang.

Bear in mind that it is '''controllers' job to decide on wingspan room'''. Aircraft will taxi, and if you don't look out, [http://www.youtube.com/watch?v=ayCWSm1f9qk this] happens. If in doubt (as on VATSIM, you only have a scope and no window), warn the pilot and ask if he is able to pass without hitting anything.

At VATSIM, you sometimes meet pilots who apparently don't have charts and/or loose orientation - especially when it is dark and the scenery is bad. If a pilot starts sight-seeing, you can tell him to '''stop ("hold position")''' and to '''"expect progressive taxi"''', and that means: you taxi him step by step, and he is instructed to stop at every step. This is a good means to guide a lost aircraft around.

When an aircraft is approaching its assigned holding-point (and clear of possible traffic-conflict) a hand-off to next higher position (i.e. TWR) shall be initiated as soon as the aircraft is conflict-free in your area of responsibility. This means, if no other aircraft can be in the way on his way to the runway. Example for LOWW: Suppose, rwy29 is for departure. GND will line up all aircraft on taxiway M facing East, and TWR will pick them from there. Hand them over to TWR as soon as they approach the queue.

GND:AUA125, contact now Salzburg Tower on frequency 118.10, bye bye!
AUA125:contacting Tower on frequency 118,10 bye!

Air-taxiing is the Movement of a helicopter / VTOL above the surface of an aerodrome, normally in ground effect and at a ground speed of normally less than 20 KT (37 km/h). Please Note: The actual height may vary, and some helicopters may require air-taxiing above 25 FT (8 m) AGL to reduce ground effect turbulence or provide clearance for cargo sling loads.
<pre>OEATD: request air taxi to Runway 29.
GND: OEATD, contact TWR for further instructions.
OEATD: Servus Wien Tower, request air taxi to Runway 29 via Exit 13 and M.
TWR: OEATD, air taxi to Runway 29 via Exit 13 and M. wind 280 deg 5 knots
OEATD: air taxi to Runway 29 via M.
</pre>
----

=== Ground Traffic Management ===

Bear in mind, that '''it is GND's job that he can taxi freely'''. If an aircraft has clearance, it can roll without looking anywhere else than straight ahead. You must see if the way is clear. But on a busy evening, you will have 5-10 aircraft taxiing at the same time. How you do this that they don't bump into each other, is called '''Ground Traffic Management'''.

To organise the traffic on ground different techniques are available, some of them relying on the pilots seeing each other. Generally you should avoid clearing two aircraft onto crossing pathways, unless you are sure they will never meet each other. To achieve this you should instruct aircraft to hold short of taxiways in the way stated above.

There are a few tools which you can use:

====Taxiway configurations====
Only one aircraft can taxi on a taxiway, so you have to order the traffic flow. On larger airports, you set the rules where outbound and where inbound aircraft roll. For LOWW, there is a nice document by [http://www.flightdirector.net/data/VACC_Austria_ATMM.pdf Patrick Hrusa] (thanks!). For LOWI, there is a nice [[LOWI_Primer]] by Claus and Hermann.

====Step-by-step clearance====
A very secure, but time-consuming way to control. Clear the aircraft only as far as it is definitely clear:

GND: AUA251, taxi to intersection M via E.
GND: AUA251, taxi to Exit 9 via M.
GND: AUA251, taxi to gate D21 via Exit 9.

You need a lot of time and patience for this, and with more traffic, you will end up in an overload soon.

====Conditional clearance====
This provides much more flow, but you have to think in advance. See, which aircraft approach to where and give one of them a conditional clearance to stop some point and give way. Make sure that the condition is clear: a specific intersection, a precise plane from a precise direction, like this:

GND: AUA251, taxi to gate D21 via E, M and Exit 9, hold short M for company A320 turning on M from your right.

"Conditional clearance" means: AUA251 is free to taxi until its final clearance limit (D21), but stops inbetween until the condition is met, in this case: another Austrian A320 taxiing (presumably on D) and turning in before him. Then, he is free to continue without instruction. "Hold short" means: You are cleared to your destination, but you should stop inbetween.

====Intermediate instructions====
Sometimes, things go differently as expected: Aircraft stop to sort out checklists, or they speed up. You might need to re-clear or stop the plane, like:

GND: AUA251, hold position, say again: hold position
GND: AUA251, continue.
GND: AUA251, hold short intersection W for a B190 crossing from your right to your left.
GND: AUA251, gate change, taxi to gate F1 via M, Exit 12 and taxilane 34, hold short Exit 12 and give way to B737 crossing from left to right.

====Progressive Taxi====
Some pilots don't know how to taxi, and some don't know where to taxi, and they can drive you mad. To them, you can issue progressive taxi instructions:

GND: Leipzig Air 600, hold position, expect progressive taxi.
GND: Leipzig Air 600, turn next left hold next intersection.
GND: Leipzig Air 600, turn right, on third intersection left and hold.

Consider the following situation:

{| class="prettytable"
|-
| You are the Ground Controller at Vienna Airport. Runways active are 34 for landing and 29 for departure. DLH6KM has vacated rwy 34 and requests taxi to its parking position. LZB421 is ready for taxi at stand 7Q.
|}

GND:DLH6KM taxi to stand C40 via taxiway D and L.
DLH6KM:Taxiing to stand C40 via D and L, DLH6KM.
LZB421:Wien ground LZB421 stand 7Q, ready for taxi.
GND:LZB421, taxi taxiway W, hold short of taxiway L.
LZB421:taxiing via W holding short of L.

{| class="prettytable"
|-
| The aircraft are now both approaching the intersection L/W.
|}

GND:LZB421, give way to the DLH B737 crossing left to right on L, thereafter continue
taxi to holding point runway 29 via taxiways Exit 2, M and A1.
LZB421:Giving way to the 737 from left to right, then continuing taxi to holding point
runway 29 via Exit 2, M and A1.

Of course you have to make sure that this instruction is unambiguous, so there shouldn't be two DLH B737s in the area. Also in low visibility operations this procedure might not work very well, in this case you might have to give the aircraft the instruction to continue taxi when the other aircraft has passed. In some cases it is also useful to let one aircraft follow the other:
<pre>GND:LZB421, follow the Austrian DASH 8 crossing you right to left on M to holding point runway 29.
LZB421:following the DASH 8 crossing us right to left on M to holding point runway 29.
</pre>
----

=== Intersection departure ===

Some flights do not need the whole length of their given departure runway so they might request takeoff from an intersection somewhere down the runway. This procedure is called a intersection takeoff. You should only grant this in coordination with Tower and if traffic situation permits. Also at some airports intersections are used to be more flexible in the departure sequence (see section [[Study Guide:Tower#Departure_Seperation_-_Based_on_Type_of_Aircraft_and_departure_route|Departure Seperation]]).

----

=== Special Situations (High Traffic, Slots, ...) ===

==== Slots ====

In case the above mentioned slot regulations are in force ground has the responsibility to set up a departure sequence in a way that the aircraft do not miss their slot.

==== Opposite runway operations ====

At some austrian airports it is very common to use opposite runway configurations (departure and arrival runway are opposite to each other). In these situations it can happen very fast that you have two aircraft facing each other nose to nose. Special attention should be paid to avoid this situation.

==== Mind the wingtip: Size matters to GND controllers ====

As GND controller, you have to watch out for the size of an aircraft. You have two indications for the aircraft size in Euroscope: The Letter "L/M/H/S" in the flight strip, and the precise aircraft type in the departure list or tag - an abbreviation which you might need to google, but you will learn over time.

* '''Light aircraft''' (L) need to go to stands, not to docks (you won't want to dock a Cessna, will you?). But "light" is not "light" - on some GAC aprons the aircraft has to be really light, especially when it comes to grass surface. Watch out to the aircraft type.
(A Cessna 172 taxiing in front of an A330:) Tower, confirm I should taxi before the Speedbird A330?
(Tower, smiling:) Confirmed, she's not hungry.

* '''Medium aircraft''' have a different trouble: Some of them (like the Beech 99, the Dash or the Avro RJ are medium, but they need stands. Others, not much bigger, like the Fokker 70 or 100, can dock at the gate, whereas others (like the A319), only a little bigger, usually dock. In doubt: ask the pilot. The medium category goes up to the most-frequent cruisers A320 and B737.

* '''Heavy aircraft''' are (almost) everything above: A330, B757, B767 and B747, the MD11 and the new B787. They almost exclusively dock, but there is another risk: Not all docks are suitable for heavies - ground charts tell you more. Look here to [[Vienna]] to see where you can park which birds.

* '''Superheavy aircraft''' is in fact only one: The A380. There are no suitable docks for A380's in Austria - they park on large stands. Take care with those albatrosses when issuing taxi instructions: Many taxiways (like L in Vienna) are simply not made for this wingspan. [[http://www.youtube.com/watch?v=zVIOCVg1G4E This]] could happen.

'' Prev: [[Study Guide:Delivery]] - Overview: [[Study Guide]] - Next: [[Study Guide:Tower]]''

[[Category:Documents]] [[Category:Study_Guides]] [[Category:Training]] [[Category:Controller]]

Study Guide:Tower

2014-01-12T09:51:16Z

Frederic Gierlinger: AUA26T can not reply with another call sign than "AUA26T"

'''This study guide is still work in progress. Stay tuned for further chapters.'''

'' Prev: [[Study Guide:Ground]] - Overview: [[Study Guide]] - Next: [[Study Guide: Approach]]''

== Introduction ==

This Study Guide is designed to give you all the information you need to become a Tower Controller within VACC Austria. We assume that you have already read the [[Study Guide:OBS]], [[Study Guide:Delivery]] and [[Study Guide:Ground]] and that you have some experience controlling on VATSIM.
Since you will handle aircraft in the air for the first time, we want to discuss some basic principles of flying before actually talking about procedures. Also we'll have to talk about some organisational issues. The fourth chapter of this article will then familiarize you with the procedures you need for controlling tower positions.

Euroscope Visibilty Range for Tower should not exceed 50nm (regarding to Vatsim CoC C12)

== Aircraft and basic Flying Principles ==

=== Producing Lift ===

For an aircraft to fly the lift force produced by (mostly) the wings has to outweigh the gravitational force that affects the aircraft.

Basically a wing produces lift by deflecting the air it moves through into one direction. According to Newton's third law of motion the lift is produced into the opposite direction. This lift grows with the speed the aircraft has in relation to the air and with the angle the wing draws with the direction of movement. This angle is called Angle of Attack (AoA).

The principle only works as long as a steady airflow around the wing exists. As soon as the airflow seperates from the wings surface the lift starts to decerease. The AoA at which this occurs is called critical Angle of Attack. It depends on the profile of the wing and it's dimensions but for subsonic aircrafts it typically lies between 8 and 21 degrees.

Think of an level flying aircraft that reduces it speed. In order to compensate the reducing lift the pilot has to raise the nose. However at some point the Angle of Attack will cross the critical angle of Attack and the pilot will find himself in a stall. So the speed of an aircraft is limited on the lower side by the so called stall speed but the aircraft is also limit by aerodynamics in higher range of speed (buffeting). Because the stall speed depends on the profile most aircraft are equipped with devices that alter the profile during flight such as flaps or slats (Approach). In General when an aircraft fly it will produce thrust but at same time it produce drag. So if you fly just horizontal (cruise) you have at the same time Lift=weight and thrust=drag. Drag produce automatic noise and that is the big problem. to prevent this we have different procedures in the approach and a lot of research in aviation to reduce the sound of the aircraft but the main part are the engines.

On approach pilots have to fly in a certain speed range in order to conduct a safe landing. The lower boundary is called landing reference speed and is often a fixed multiple of the stall speed. As a result of this the approach speed also depends on weight an aircraft configuration (Flap/Slat setting). For safety the Approach Vapp is higher than Vref and the difference depends mostly on the weather conditions.

Generally you can say that bigger aircraft also have a bigger approach speed however at some point this rule does not work anymore because the Vref depends largely on the aircrafts weight in relation to it's maximum takeoff weight (MTOW). The speed ranges from 50 knots in a C150 up to 170 knots with a fully loaded 747. However for example it is possible that a light 747 is slower than a fully loaded 737.

=== Aircraft Categories ===

The most important ways of categorizing aircraft in aviation are by weight or by approach speed.

==== Weight Categories ====

Aircraft are categorized into three weight categories:

{| class="prettytable"
|-
| '''Category'''
| '''MTOW'''
|-
| Light Aircraft (L)
| < 7 000 kg
|-
| Medium Aircraft (M)
| 7 000 – 136 000 kg
|-
| Heavy Aircraft (H)
| >136 000 kg
|}

You can find a list of aircrafts in this link [http://www.skybrary.aero/index.php?title=Category:Aircraft&until=D228] Weight depicted is MTOW.

==== Approach Speed ====

Aircraft are categorized by their reference approach speed (Vref) at maximum landing weight:

{| class="prettytable"
|-
| '''Category'''
| '''Vref'''
|-
| A
| <= 90 knots
|-
| B
| 91 - 120 knots
|-
| C
| 121 - 140 knots
|-
| D
| 141 - 165 knots
|-
| E
| >= 165 knots
|}

==Before you start controlling==

Tower is responsible for all movements on the runways as well as for all movements within the control zone. He decides which runways are in use and maintains the ATIS. Tower is also responsible for ground and delivery if they are not online.

=== Airspace Structure around Major Airports ===
Major airports in Austria are surrounded by a so called control zone which is a class D airspace. This means that all aircraft need a clearance to enter this piece of airspace. So either they are cleared to an approach or you need to clear them specifically into the control zone. Details will be discussed in the VFR part later on.

===Choosing the active runways===
The guiding principle in choosing the active runways is that aircraft prefer to depart into direction the wind is coming from.
An airport has one runway named 16/34. The wind is reported as 320 degrees at 14 knots. In
this case runway 34 is chosen as the active runway.
However due to noise abatement and terrain considerations most airports have some kind of preferential runway system. Tailwind components of up to five knots are normally accepted in these cases.
Bear in mind that it is the pilots decision whether he can accept a certain runway because only he knows the performance of his aircraft.

For details on the preferred runway configurations for a specific airport ask your mentor.

=== ATIS ===

ATIS stands for Automatic Terminal Information Service and is a usually automatically generated broadcast that contains essential informations for pilots. It is continuously broadcasted on a dedicated frequency. On initial contact with the controller, pilots should already have listened to the ATIS and state the identifying letter.

A ATIS broadcast has to consist of:

*Name of the Airport
*Identification Letter
*Time of Observation
*Active Runways
*Transition Level
*Wind direction and velocity
*Visibilities
*Special weather conditions (such as rain)
*Cloud ceiling
*Temperature and Dewpoint
*QNH
*Trends

It is updated every 30 minutes or as soon as significant changes occur. In practice the ATIS function of Euroscope should be used. You can find the necessary files [http://www.vacc-austria.org/index.php?page=content/static&id=SOFTWARE_ATC here]. Please consult enclosed readme for information how to use this package.

 

=== Transition Altitude/Transition Level ===

Knowing the altitude you are flying is one of the most important informations you need in order to safely operate an airplane. Aircraft Altimeters use the air pressure around them to determine their actual altitude. In order to get correct readings you have to use the actual local pressure in your area. As a memory hook you can use this: The altimeter needle moves in the same direction you turn the rotary knob to adjust the pressure. If you turn it counterclockwise, the needle also turns counterclockwise and therefor indicates a lower altitude.

On the other hand it would not be very practical to use the local pressure while flying at higher altitudes, since terrain is not an issue here and you would have to set a new pressure setting in your altimeter every few minutes.

To avoid this pilots use the local pressure when departing from an airport until they pass the so called Transition Altitude (TA), where they set the so called standard pressure (QNH 1013 hpa or Altimeter 29.92 inHg). They continue to use this setting until they descend through the Transition Level (TRL) at their destination airport (or an airport on their route), where they set the local pressure again.

In airport charts only TA is given, whereas TRL has to be determined by ATC. Use the following table to calculated your TRL:

QNH < 0977: TA + 3000 ft.
QNH 0978 - 1012: TA + 2000 ft.
QNH 1013 - 1050: TA + 1000 ft.
QNH 1051 >  : TA = TL

The room between TA and TRL is called Transition layer. It ensures that the minimum spacing of 1000 ft between aircraft flying in lower part (with local pressure) and the upper part (using Standard pressure).

== Working as a Tower Controller ==

===Setting the right priorities===
The moment you are responsible for more than one aircraft you will have to set priorities in your handling. As a general guideline:

#aircraft in the air have top priority - you take care of them first. Reason: They can't stop.
#aircraft moving on the ground have next priority. They could bump into each other.
#aircraft standing on ground have the least priority.

This also means that you will have to tell pilots to stand by while you attend to other matters. Make sure you keep a list of aircraft you told to stand by so you don't forget to call them back. This also means, that you might have to set priority in services which aircraft in the air need first, like setting up ATIS.

=== Runway Separation ===

The runways are one of the most dangerous spots on an airport because aircraft are travelling at high speed with little room to maneuver and most of the time no ability to stop at a reasonable distance. Because of this the general rule is that '''only one aircaft may be cleared to use a runway at the same time.''' What this means practically and exceptions from this rule are explained in the following chapters.

=== Departing Traffic ===

So now we are at the point where the pilot reaches the Holding Point of his departure runway and reports ready for departure. What are the things you should check before issuing the takeoff clearance?

*Have a look at the flightplan. Take note of the type of aircraft and the Departure Route.
*Check the traffic approaching the runway.

To give him the takeoff clearance the following phrase should be used:

e.g.: TWR: AUA2CM, wind 320 degerees, 7 knots, Runway 29, cleared for takeoff.
AUA2CM: Cleared for takeoff Runway 29, AUA2CM

The pilot lines up on the runway, advances the throttle and takes off. When he is well established in climb check he is squawking Mode C and the right Code. Afterwards he is handed off to the next Controller, in this case a radar position:
<pre>LOWW_TWR: AUA2CM, contact Wien Radar frequency 128.20, bye bye!
AUA2CM: Contacting Wien Radar frequency 128.20, AUA2CM. </pre>
The next aircraft reports ready for departure. Again check the points above, but this time we cannot give the takeoff clearance straight away because the preceeding aircraft is still occupying the runway. Now you get to know the first exception to the Runway Seperation rule above. To speed things up you can instruct the next aircraft to line up behind the first one while this one is still in the takeoff roll occupying the runway:

TWR: AZA639, behind departing Austrian Airbus A319, line-up rwy 29 and wait behind.
AZA639: behind departing Airbus lining up runway 29 and waiting behind, AZA639.
''Note: you '''must''' add another "behind" at the end to make sure the aircraft really waits before lining up!

This type of clearance is called a conditional clearance. The earliest possible point where you can issue the next takeoff clearance is, when the preceeding aircraft has overflown the opposite runway end or has clearly turned onto either side of it. However in some cases this could be very close which leads us to the next chapter but before lets have a look on helicopters.

Helicopters are sometimes able to start from there current position like a Helipad or a normal stand, if he want to depart from a Runway you can use the normal Phrases for VFR Traffic.

e.g.: OEATD: Wien Tower, OEATD at General Aviation Parking ready for departure.
TWR: OEATD, Wien Tower, after departure leave control zone via Freudenau and Donauturm, 2500 feet or below, Wind 290° 6 Knots, present position cleared for take-off.
OEATD: After departure leaving the control zone via Freudenau and Donauturm not above 2500 feet, present position cleared for take-off.

=== Departure Seperation ===

==== Based on Type of Aircraft and departure route ====

One of the main tasks of air traffic control is to keep aircraft at a safe distance to each other. So imagine the following situation:

{| class="prettytable"
|-
|
*Two aircraft are departing right after each other.
*The first aircraft is a relatively slow Cessna 208 (~around 70 knots in climb), the second one a fast Boeing 767 (140-180 knots on the initial climb).
*Both follow the same departure route.

|}

Obviously it would not take long until the B767 catches up with the Cessna, a potentially very dangerous situation! You can see, that it is very important to check the flightplan of the aircraft you are about to clear for takeoff. The minimum radar seperation in the area around an airport is 3 nm or 1000 feet. These are the limits radar stations have to obey. Tower Controllers should aim to achieve the following seperation for departing aircraft following departure routes which share a common part:
<div align="left">
{| class="prettytable"
|-
| Fast followed by slow
| 3 nm
|-
| Matching Types
| 5 nm
|-
| Slow followed by fast
| 10 nm
|}
</div>
In extreme examples like the one above it is often more advisable to coordinate with APP to find another solution. Often this involves clearing the aircraft to a non standard altitude or departure route:

TWR: DLH2441, after departure maintain runway heading, climb initially to 3000 ft
DLH2441: After departure maintaining runway heading, climbing to 3000 ft, DLH2441
TWR: DLH2441, wind 320 degrees at 9 knots, runway 29, cleared for takeoff
DLH2441: Cleared for takeoff runway 29, DLH2441

The other main task of ATC is to expedite the flow of traffic. Situation:

{| class="prettytable"
|-
|
*You have numerous aircraft departing from the same runway, following different departure routes. Some of them involve immediate right turns other SIDs immediate left turns.
*There are two holdingpoints available.

|}

It would benificial to use the gaps that arise between the aircraft using similar Departure Routes, so in close coordination with ground you should try to distribute aircraft over the holding points in a way to be able to fill those gaps.

==== Based on Wake Turbulence Category ====

There are two ways aircraft influence the air around them when passing through it:

{| class="prettytable"
|-
|
*Jetwash produced by the engines
*Turbulence created at the wings and especially at the wingtips

|}

This turbulence can cause severe problems or even loss of control for following aircraft. The wake turbulence categories are based on the Maximum Takeoff weight (MTOW) of the aircraft:
<div align="left">
{| class="prettytable"
|-
| Light Aircraft (L)
| < 7 000 kg
|-
| Medium Aircraft (M)
| 7 000 – 136 000 kg
|-
| Heavy Aircraft (H)
| >136 000 kg
|}
</div>
For departing aircraft, 2 minutes separation (3 minutes if the succeeding aircraft departs from an intersection) is applied when an aircraft in wake turbulence category LIGHT or MEDIUM departs behind an aircraft in wake turbulence category HEAVY, or when a LIGHT category aircraft departs behind a MEDIUM category aircraft. You may issue a take-off clearance to an aircraft that has waived wake turbulence separation, except, if it's a light or medium aircraft departing as follows:

{| class="prettytable"
|-
|
*Behind a heavy a/c and takeoff is started from an interception or along the runway in the direction of take-off.
*Behind a heavy a/c that is taking off or making a low or missed approach in the opposite direction on the same runway.
*Behind a heavy a/c that is making a low or missed approach in the same direction of the runway.

|}

To point out this hazard to a pilot the following phrase should be used:

TWR:ESK32C, behind departing heavy B777 line up runway 16 behind and wait,
caution wake turbulence.
ESK32C: behind departing B777 lining up rwy 29 and waiting, ESK32C.

=== Arriving Traffic ===

Arriving Aircraft call you when they are established on an approach to a runway. Most of the time this is an ILS Approach but also other kinds are possible.

MAH224:Linz Tower, MAH224 established ILS Approach rwy 27.

Again you are not allowed to clear more than one aircraft onto the same runway at the same time. 

{| class="prettytable"
|-
| In order to issue a landing clearance
#preceeding departing traffic must have overflown the opposite runway threshold or clearly turned onto either side of the runway.
#preceeding landing traffic must have left the runway safety strip with all parts.
#traffic crossing the runway must have left the runway safety strip with all parts.

|}

If these conditions are met use the following phrase to clear the aircraft:

TWR:MAH224, Linz Tower, wind 300 degerees at 16 knots, runway 27, cleared to land.
MAH224:cleared to land runway 27, MAH224.

During periods of high traffic it is likely that you have more than one aircraft approaching the same runway at the same time. Approach has to ensure the minimum radar seperation of 3 nm and additionally increased seperation due to wake turbulence.

AUA26T:Linz Tower, AUA26T established ILS 27.
TWR:AUA26T, Linz Tower, continue approach, wind 300 degrees at 16 knots.
AUA26T:continuing approach, AUA26T.

{| class="prettytable"
|-
| Meanwhile MAH224 has left the runway.
|}

TWR:AUA26T wind 310 degrees at 14 knots, runway 27 cleared to land.
AUA26T:Runway 27, cleared to land, AUA26T.

Often it is useful to give pilots additional information, such as traffic information or wind:

{| class="prettytable"
|-
| CSA276 is following NLY7751 (A320):
|}

CSA276: Wien Tower, CSA276 established ILS 34.
TWR:CSA276, Wien Tower, preceeding traffic is a NLY Airbus A320 3,5 nm ahead of you, continue
approach runway 34, wind 010 degrees at 4 knots.
CSA276:We have the airbus in sight continue approach, CSA276.

{| class="prettytable"
|-
| AUA81 is approaching runway 16, OE-AGA is on left base runway 16 and there is a rescue helicopter operating in the area around Freudenau.
|}

AUA81:Wien Tower, AUA81 established ILS 16
TWR:AUA81, Wien Tower, VFR traffic is on left base rwy 16, continue approach, wind 140
degrees at 7 knots.
AUA81:continuing approach, AUA81.
TWR:AUA81, There is an helicopter operating west of the extended centerline, presently at
your one o'clock position, 5 nm, 1400 ft.
AUA81: Thank you, looking out, AUA81.
AUA81: traffic in sight, AUA81.

Helicopters don't need a Runway for the approach, sometimes they are able to land at their parking position, lets have a look on the Phrases.

eg. the rescue helicopter from the example above needs to land on your airport:
OEATD: Wien Tower, request landing at the General Aviation Terminal.
TWR: OEATD, wind 010 degreees 4 knots direct General Aviation Terminal, cleared to land.

To give you an idea how dense traffic can get in real life consider that during peak times and good weather the seperation is reduced to 2,5 nm. This equals to one landing every 75 seconds. However on VATSIM the minimum seperation is 3 nm which already requires good cooperation from all the pilots involved.
You can check this site to see a normal peak time. the capacity from EGLL (London) has reached the 90 percent. Make a replay from one day and you can see further problems in the aviation ....[http://casperflights.com/]

=== Merging Departing and Arriving Traffic ===

And now to the most fun part of being a Tower Controller. Sometimes you get into the situation that you use the same runway for departures and arrivals. Either your airport has only one runway or weather demand this configuration.

 Still the above rule of only one aircraft at the same time applies, however we also use conditional clearances which look very similar to those above in the departing traffic section.

LOWW_TWR: AUA123, Traffic short final RWY 29, C750, report in sight
AUA123: Traffic in sight, AUA123
LOWW_TWR: AUA123, behind landing C750 line up RWY 29 behind and wait
AUA123: Behind landing C750 lining up RWY 29 behdind and waiting, AUA123

To avoid misunderstandings, this time we make sure that the Pilot has the the landing aircraft in sight. You don't have to worry about wake turbulence seperation between landing and departing aircraft since they never cross through each others wake.

To depart an aircraft in front of an approaching aircraft at the time of the departure clearance given the arriving aircraft should not be closer than 4 nm to touchdown. To squeeze a departing aircraft between two arrivals you normally need a minimum of 6 nm between them. It is important for you to check carefully if you have the necessary gap, so have a close look at the distance between the arrivals and their speed. If the second one comes in faster than normal consider this in your calculation. Also you should make sure, that the pilot will be ready for departure when you need him to depart. To check this use the following phrase:

Callsign, are you ready for immediate departure?

Again it is a good idea to give the pilot an idea of the traffic situation around him.

Example:

{| class="prettytable"
|-
| You are the Tower Controller at Vienna airport. Runway 29 is active for departures and arrivals. One aircraft is on a 5 nm final, one at 12 nm out. Additionally you have two departures waiting at the holding point of ruwnay 29.
|}

TWR:CAL275, are you ready for immediate departure?
CAL275:Affirmitive, ready for immediate departure, CAL275
TWR:Traffic is now at a 4 nm final, wind 300 degrees at 7 knots, runway 29 cleared for
immediate takeoff.
CAL275:cleared for immediate takeoff runway 29, CAL275

{| class="prettytable"
|-
| After the CAL B747 has taken off.
|}

TWR:AUA289, wind 300 degrees at 7 knots, runway 29, cleared to land.
AUA289:Runway 29, cleared to land, AUA289.
TWR:AUA2LT, traffic is an AUA Airbus A320 on a 2 nm final rwy 29, do you have traffic in sight?
AUA2LT:Traffic in sight, AUA2LT.
TWR:AUA2LT, behind landing traffic line up runway 29 behind and wait.
AUA2LT:Behind the landing Airbus, lining up runway 29 behind and waiting, AUA2LT.

{| class="prettytable"
|-
| AUA289 has vacated the runway.
|}

TWR:AUA2LT, wind 300 degrees at 8 knots, runway 29 cleared for takeoff, landing traffic is
now on a 3,5 nm final.
AUA2LT:cleread for takeoff runway 29, AUA2LT.

=== VFR Traffic ===

==== Differences to handling of IFR Traffic ====

The essential collision safety principle guiding the VFR pilot is "see and avoid." Pilots flying under VFR assume responsibility for their separation from all other aircraft and are generally not assigned routes or altitudes by air traffic control. Governing agencies establish specific requirements for VFR flight, consisting of minimum visibility, distance from clouds, and altitude to ensure that aircraft operating under VFR can be seen from a far enough distance to ensure safety.

To guide VFR TRaffic through your airspace you make use of VFR Routes, Sectors and reporting Points. '''Used phrases''':

TWR:OE-AGA, enter control zone via VFR route Klosterneuburg – Freudenau, 2500ft or below,
QNH 1020, Squawk 4604, report XXXX (i.e. Freudenau), expect runway 29.
TWR:OE-AGA hold (orbit) overhead XXXX (i.e. Freudenau) in XXXX (i.e. 2500ft)

VFR flights should be guided into downwind, base and final leg for landing. 

TWR:OE-AGA, enter downwind for runway 29, report on downwind
TWR:OE-AGA, enter base for runway 29, report on base

VFR Flights get their Clearance from Tower. After startup, they will contact Ground for taxi, thereafter the Tower will issue the clearance. A possible VFR clearance could be: 

TWR:OE-AGA, verlassen Sie die Kontrollzone über Sichtflugstrecke Klosterneuburg, 1500 Fuß
oder darunter, QNH 1014, Squawk 4607, Rechtskurve nach dem Abheben so bald als möglich.
TWR:OE-AGA, leave controlzone via VFR-route Klosterneuburg, 1500 feet or below,
QNH 1014, Squawk 4607, right turn after departure as soon as possible.

TWR:OE-AGA, steigen sie auf 3500 Fuß, melden Sie Donauturm.
TWR:OE-AGA, climb 3500 feet, report Donauturm.

In the air ATC provides traffic information.

TWR:OE-AGA, Traffic at your 12 o'clock position, 2100 feet, a PA28 on VFR inbound
route Klosterneuburg-Freudenau.

When the aircraft leaves the controlzone.

TWR:OE-AGA, set Sqauwk 7000, leaving frequency is approved.

Wien Tower/Turm can also be contacted in German.

==== Merging in VFR Traffic ====

To manage VFR Traffic efficiently you have to use traffic information and visual seperation.

TWR: OE-ANX, traffic at your 3 o´clock position, moving right to left, B767, distance 2.5
miles, report mentioned traffic in sight
OE-ANX: Traffic in sight, OE-ANX

Because of other traffic it might be necessary for the aircraft to remain in the downwind leg until the traffic has passed:

TWR:OE-AGA, fly extended right downwind, standby for base.
OE-AGA: Extending right downwind, OE-AGA

To instruct the aircraft to continue it's approach use the following procedure:

TWR: OE-ANX, traffic at your 3 o´clock position, moving right to left, B767, distance 2.5
miles, report mentioned traffic in sight
OE-ANX: Traffic in sight, OE-ANX
TWR:OE-AGA, behind B767 traffic, enter final RWY 29, caution wake turbulence
OE-AGA: Behind B767, enter final RWY 29 behind, caution wake turbulence, OE-ANX

When using an extended downwind you should always consider that the aircrafts speed might be considerably lower than the speed of other aircrafts involved. So if an aircraft has to fly a long way out it might take some time for it to come all the way back, generating a big gap in the arrival sequence. Instead you should aim to keep the plane within the vicinity of the airfield:

TWR: OE-AGA, Make a right three-sixty.
OE-AGA: Making three-sixty to the right.
TWR: OE-AGA, Orbit left
OE-AGA: Orbiting left, OE-AGA

The second instructions means, that the pilot should make orbits until further advice.

==== Information Positions ====

=== Coordination with other ATC Stations ===
''Communication from one controller to another is as important as the communication from controller to pilot.'' This is especially true during high traffic situations where you might be tempted to concentrate solely on what is happening on your frequency. In these situations don't hesitate to take a call from a fellow controller even if it means that a pilot has to wait before you call him back. Secondly if you know a controller is busy, try to keep your conversation with him concise and avoid chatting in a teamspeak channel next to him.

Within VACC Austria we usually use teamspeak to coordinate with each other. The coordination with other ATC units is mostly done per private chat.
Other means of communication are the Intercom functions of Euroscope which would be a very nice feature, however often they only work with certain controllers. The ATC Channel within Euroscope should not be used for individual coordination.

When you come online or go offline you should inform neighboring ATC stations.

=== Special Situations (High Traffic, Slots, ...) ===

==== High traffic situations ====

During high traffic situations communication with adjacent approach sectors is very important. Especially during single runway operations you might have to ask for increased inbound spacing to be able to fit in departing aircraft.

==== Additional phrases during periods of high traffic ====

In order to expedite the flow of traffic use the following phrases:

Austrian 125, wind is xxx/xx runway 29 cleared for takeoff, expedite
Austrian 125, wind is xxx/xx runway 34 cleared to land, expedite vacating
OE-ABC, wind xxx/xx, runway 29 cleared for takeoff, after departure right turn
as soon as practicable

==== Opposite runway operations ====

This is one of the more difficult situtions for a Tower controller. You have to consider the departure route of each aircraft to estimate the required spacing to arriving traffic. Again close coordination with approach is very important.

== Ressourcen ==

*[http://vateud.net/index.php?option=com_content&view=article&id=77&Itemid=122 VATEUD Training Department]
*[http://de.wikipedia.org/wiki/ICAO-Alphabet Wikipedia: Buchstabentafel]

 
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