Difference between revisions of "Study Guide:Delivery"

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...after some minutes...
...after some minutes...
  TWR: OE-DLT, wind 160 with 12 knots rwy 16 clr T/O. After Departure you are cleared for left hand traffic pattern 1500 ft or below, report final.
  TWR: OE-DLT, wind 160 with 12 knots rwy 16 clr T/O. After Departure you are cleared for left hand traffic pattern 1500 ft or below, report final.
OE-DLT: clr T/O, after dep left hand traffic pattern, report final
OE-DLT: clr T/O, after dep left hand traffic pattern, report final
'''Important Note''':
'''Important Note''':

Revision as of 08:10, 16 July 2012

Prev: Study Guide:OBS - Overview: Study Guide - Next: Study Guide:Ground


This Study Guide has been designed to give you all the information needed to start controlling as a Clearance/Delivery controller on the VATSIM network. It assumes, that you have read and understood the Study Guide:OBS before.

Working Delivery Positions

Clearance Delivery is responsible for checking and correcting flightplans of departing aircraft and issue routing clearances to them. This task may sound boring, but is important for upstream controllers: Clearances take time (on the radio) and may block vital commands (like takeoff and landing clearances), and radar stations rely on the checked and cleared values (SIDs and clearance altitudes) for their controlling. If DEL makes mistakes, APP will notice.

There are 2 types of flight plans at VATSIM:

  • IFR: Any pilot who flies IFR must file a flight plan. It contains the exact routing from departure to arrival, cruise altitude and some more information which controllers need for their job.
  • VFR: VFR pilots can file flight plans, but they don't need to. They can simply ask for taxi clearance, take off and continue in uncontrolled airspace.

Flightplan Structure

Flight plans are documents filed by pilots with the local Civil Aviation Authority prior to departure. They generally include basic information such as departure and arrival points, estimated time en route, alternate airports in case of bad weather, type of flight (whether instrument flight rules or visual flight rules), pilot's name and number of people on board.

For IFR flights, flight plans are used by air traffic control to initiate tracking and routing services.

Aircraft routing types used in IFR flight plans are: Airway, Navaid and Direct. A route may be composed of segments of different routing types.

  1. Airway: Airway routing occurs along pre-defined pathways called Airways. Mostly aircraft are required to fly airways between the departure and destination airports. The rules cover altitude, airspeed, and requirements for entering and leaving the airway (SIDs and STARs). Airways have letters and numbers like "Y868 or "UM125".
  2. Navaid: Navaid routing occurs between Navaids (short for Navigational Aids) which are not always connected by airways. Navaid flight plans are used for IFR aircraft which don't have a GPS receiver - they can't follow waypoints. Navaid routing is typically only allowed in the continental U.S. If a flight plan specifies Navaid routing between two Navaids which are connected via an airway, the rules for that particular airway must be followed as if the aircraft was flying Airway routing between those two Navaids. Allowable altitudes are covered in Flight Levels.
  3. Direct: Direct routing occurs when one or both of the route segment endpoints are at a latitude/longitude which is not located at a Navaid.

For VFR flights, their only purpose is to provide needed information should search and rescue operations be required. At VATSIM, a VFR flight plan is handy for controllers, as it shows vital information with the airplane tag on the radar, like the destination.

Workflow for DEL controllers

1. Setup

When you log in as DEL, you have to do two things (if waiting pilots jump on you, tell them to stand by until you have done it!):

  1. Check with the upstream controller (TWR, APP, CTR) for active runways and set active airport and runways in your Euroscope "active runways" dialogue box.
  2. Check with the upstream controller the active ATIS letter. Set your ATIS dialog box to your airport and the active letter, but don't connect (ATIS is TWR's job). Set this way, Euroscope will show the valid ATIS letter in your METAR list and you don't need to ask every few minutes. If there is no ATIS, then check active runway and wind, as you will need to tell this to pilots.

2. Check the flight Plan

At VATSIM, the journey starts with an aircraft popping up at an airport. Initially, the tag (in Euroscope) will show "NOFP", meaning: No flight plan filed so far. Some time later, a destination and more will show up, and that means: The pilot has filed a flight plan. On this point, DEL controller work starts. At this point, Euroscope has done already some work for you. DEL's job is to check and complete it, and to give clearance to the pilot. First, Check, if it is a VFR or IFR flight plan.

For IFR flight plans, ...

  • Check, if "From"-Airport is yours and "To"-Airport makes sense. It is unlikely that a C72 will fly to GATB (Timbuktu) without stopovers, as well as a B737 flies VFR to KJFK. If anything looks wrong, then ask the pilot to refile the flight plan.
  • Check, if departure runway corresponds to the active runway. If not, then check your runway settings in Euroscope.
  • Check, if cruise altitude is correct: Cruise altitude is stated in flight levels (hundreds of feet): FL280 means 28000 feet (at QNH 1013, to be really correct). For flight levels below FL410, westbound flights have even flight levels, and eastbound flights have odd flight levels. Above FL410, flight levels increase by 20: west is FL430-470-510-550 etc, east is 450-490-530-570 etc. If the cruise altitude is wrong, ask the pilot for the nearest correct altitudes up or down. If you want, correct the RFL or tell the pilot to file again.
  • Check, if there is a valid SID from the active runway to the first waypoint in the flight plan. If not, then look for the cause. It could be an invalid flight plan (a flight plan must contain a waypoint which is the end of a SID - most SIDs have the waypoint in their names: SITNI5B is the SID leading from LOWW rwy 16 to SITNI). If the flight plan does not contain any valid waypoint, ask the pilot to refile a correct flight plan. If the flight plan is correct, then you might need to manually select the best SID.
  • Euroscope has already selected the first matching SID in the alphabet. Check, if this SID is applicable to the aircraft and time (you might want to check with APP to clarify, which SIDs are correct), and select the best SID.

For VFR flight plans, the task is easier. usually, it contains the destination and a verbal description of the pilot's intention (could be "circuits" or "platzrunde", or "LOWL via Donau").

  • Check, if this intention is possible and makes sense (you might check with TWR).

2. Set Squawk and initial clearance altitude

  • Set a squawk now. The squawk number space is predefined for each airport and written in the sector file. For normal purposes, automatic squawk allocation in Euroscope works fine. In high traffic situations like Finally Austria, the squawk space runs out quickly, and Euroscope runs mad. The result is duplicate squawks. Technically, this is not a problem at VATSIM (as plane-data links are made by pilot ID, not by squawk code), but in reality this would be a nightmare (which won't happen as in real life squawk codes are given by a Eurocontrol centralized computer). In this case, you have to set squawk codes by hand and start to fill other squawk number spaces, like 2500+. Don't attempt to set a squawk with a number higher than 7 - squawks are octets and don't have 8 and 9 (4707 is good, 4708 does not work).
  • Set the initial climb altitude. This differs from airport to airport. LOWW has 5000ft for all SIDs ("A50" in the list), LOWI has FL160 for all SIDs, and Salzburg has different altitudes for different SIDs (look into the SID description).

3. Wait for initial contact

ATC is a service job - you wait for the pilot to come to you, as in real life you don't know if the pilot is on your frequency at all. At some point, the aircraft will call you, ideally with the first (long) phrase. When congested, the short form is used:

LHA123: Wien Delivery, servus. Laipzich Air 123, Info B on board, gate C31, Fokker 70, requesting IFR clearance to München.
LHA456: Wien Delivery, Laipzich Air 456 ready to copy IFR clearance.

4. Issue IFR Routing Clearances

First, clear everything which is wrong or unclear in the flight plan, something like ...

DEL: Leipzig Air 123, servus. Sir check your flight plan you fly eastbound in that case your flight level must be an odd flight level.
What do you prefer flight level 310 or 290?
LHA123: Flight level 310, Leipzig Air 123.

Then, issue your clearance:

DEL gives routing clearances to all departing aircraft with the following information:

Destination of flight
SID (= Standard instrument departure) Normally the filed SID is given
Initial climb altitude after departure (5000ft)
Squawk (Squawk assignments for LOWW are 4600 to 4620)
ATIS (which ATIS letter is current)
CTOT (= Calculated take-off time) Slot time (Normally not used on the VATSIM network)

The bold marked points are mandatory, all other points are optional.

Normal construction of a routing clearance:

Callsign, cleared to XXXX via XXXXX XX departure, (initial climb 5000ft), Squawk 46XX


Austrian 125, cleared to Frankfurt via LUGIM 1C departure, initial climb 5000ft,
 Squawk 4601, info B is current.

Some Aircraft are not able to follow SIDs for various reasons, most of the time due to missing equipment. In these cases you should issue a so called vectored departure. A vectored departure clearance includes the same components as a normal clearance but instead of the SID you issue instructions to be carried out after departure. In this case the initial climb altitude is mandatory.

Callsign,cleared to XXXX, after departure RWY XX, XXXXXXX, initial climb 5000ft,
Squawk 46XX


Austrian 125, cleared to Frankfurt, after departure Runway 29, turn left heading 240
 expect vectors to LUGIM, initial climb 5000 ft, Squawk 4601.

You can find the instructions for each Airport within the Study Guide:Airport Details If the pilot responds with a correct readback you should answer with the following phrase:

Callsign, readback correct =>  Austrian 125, readback correct

5. Handover

Afterwards you either hand the pilot over to GND or wait for his startup request, depending on local procedures. You can do this joint with the readback answer, like:

Austrian 125, readback correct, contact Wien Ground "frequency" 121.60. Bye Bye

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

Missing ATIS

  • Maybe there is no upstream controller. Then you ask the pilot, which runway he wants to use. Then you can clear him.
  • Maybe there is a technical problem and TWR cannot connect any ATIS. In this case, you have to check with TWR, which runway is in use, and get the METAR yourself from Euroscope. If the pilot does not find any ATIS, he/she should contact you with the following phrase. Anyway, you should answer him as follows, before any other clearance is given:
LHA123: Wien DEL, Leipzig Air 123, Position E42, requesting airport information.
DEL: Leipzig 123, Wien Delivery, servus. Active runway is 34, wind 320 at 10, QNH 1030.

VFR flight plans

... are easier to clear. The Tower is always responsible for VFR Traffic.

Now one short Example: Check Study Guide: TWR for more

TWR: OE-DLT, when ready taxi to h/p RWY 16 via M, W, E, wind 160 deg 12 knots, squawk 0001, QNH 1020. report when ready
OE-DLT: taxi to h/p rwy 16 via M, W and E, squawking 0001, QNH 1020, "wind copied".

...after some minutes...

TWR: OE-DLT, wind 160 with 12 knots rwy 16 clr T/O. After Departure you are cleared for left hand traffic pattern 1500 ft or below, report final.
OE-DLT: clr T/O, after dep left hand traffic pattern, report final

Important Note: Squawk's like 4601, 4602 and so on are reserved for IFR Flights. For VFR take a Range of 0001 - 0020 for example. Keep in Mind if you have high Traffic and that is in normal time IFR its better you take sqk's like 0002 and so on.


In order to guarantee a safe flow of traffic and to minimize delays in the air so called slots are being used. A slot is a timeframe of five minutes before to ten minutes after the CTOT mentioned before. The aircraft has to depart within this timeframe from its departure airport. On the VATSIM network this system is only used on special occasions.

Behavior in situations with increased traffic

Sometimes one of your neighboring sectors has to stop accepting traffic. In these cases you should delay an aircrafts start-up clearance.

If possible you should inform the pilot about the expected delay:

Austrian 125, readback correct, expect startup in 10 minutes.
Austrian 125, startup approved, expect departure in 10 minutes.

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