# CDM Operation

<p class="callout success">CDM Procedures, What it is? How it works? How to use it? How it is intergrated into FlightStrips...</p>

[![CDM Prin.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/c75cdm-prin.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/c75cdm-prin.png)

<details id="bkmrk-cdm---explainedcdm-%28"><summary>CDM - Explained</summary>

CDM (Collaborative Decision Making) is a complex but vital part of ensuring we can cope with the traffic levels on VATSIM. In order to use CDM properly it is important that you understand

- The logic behind CDM operation
- How to effectively use CDM operation

### <span style="color: rgb(35, 111, 161);">1.1 Purpose</span>

<span style="color: rgb(0, 0, 0); white-space: pre-wrap;">The first thing you need to understand is that there are </span><u>**TWO** </u><span style="color: rgb(0, 0, 0);">(2) different kinds of CDM, They are intertwined and both must be respected.</span>

- A-CDM (Airport - Collaborative Decision Making)
- vIFF CDM (Intergrated Flight and Flow - Collaborative Decision Making)

[![Frame 8.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/frame-8.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/frame-8.png)

<span style="white-space: pre-wrap;">These two systems work towards seperate goals, but must constantly talk to eachother as they are co-dependent. </span>

A change to one of the entities can affect the other one. In order to ensure compliance we have intergrated it all in a user friendly managed manner within FlightStrips

### <span style="color: rgb(35, 111, 161);">1.2 Abbriviations &amp; Explanations</span>

Many foreign abbreviations are being used for CDM, and we need to cut it into the bone of knowing just the basics for your daily routing:

<p class="callout info"><span style="white-space: pre-wrap;">NOTE: </span>**Blue background items**<span style="white-space: pre-wrap;"> are operational items, </span>**gray background items**<span style="white-space: pre-wrap;"> are purely adminstrative and not gouvering when controlling</span></p>

<table style="width: 446.55pt; border-collapse: collapse; border-width: medium; border-style: none; border-color: currentcolor; border-image: none; margin-left: 6.75pt; margin-right: 6.75pt;"><colgroup><col style="width: 42.05pt;"></col><col style="width: 113.9pt;"></col><col style="width: 184.75pt;"></col><col style="width: 345px;"></col></colgroup><tbody><tr style="height: 28.25pt;"><td style="background: rgb(1, 60, 71); width: 42.05pt; border-width: 4.5pt 1pt 4.5pt 4.5pt; border-style: solid; border-color: windowtext; border-image: none; padding: 0cm 5.4pt; height: 28.25pt;">**TERM**

</td><td style="background: rgb(1, 60, 71); width: 113.9pt; border-width: 4.5pt 1pt 4.5pt medium; border-style: solid solid solid none; border-color: windowtext windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;">**NAME**

</td><td style="background: rgb(1, 60, 71); width: 184.75pt; border-width: 4.5pt 1pt 4.5pt medium; border-style: solid solid solid none; border-color: windowtext windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;">**DESCRIPTION**

</td><td style="background: rgb(1, 60, 71); width: 105.85pt; border-width: 4.5pt 4.5pt 4.5pt medium; border-style: solid solid solid none; border-color: windowtext windowtext windowtext currentcolor; border-image: none; padding: 0cm 5.4pt; height: 28.25pt;">**USAGE**

</td></tr><tr style="height: 28.25pt;"><td style="background: rgb(190, 245, 239); width: 42.05pt; border-width: medium 1.5pt 1.5pt 4.5pt; border-style: none solid solid; border-color: currentcolor windowtext windowtext; padding: 0cm 5.4pt; height: 28.25pt;">**EOBT**

</td><td style="background: rgb(190, 245, 239); width: 113.9pt; border-width: medium 1.5pt 1.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;">**E**<span style="color: rgb(192, 0, 0);">stimated</span>

**O**<span style="color: rgb(192, 0, 0);">ff</span> **B**<span style="color: rgb(192, 0, 0);">lock</span> **T**<span style="color: rgb(192, 0, 0);">ime</span>

</td><td style="background: rgb(190, 245, 239); width: 184.75pt; border-width: medium 1.5pt 1.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;"><span style="color: black;">The time the pilot has filed his flightplan to be ready for Startup</span>

</td><td style="background: rgb(190, 245, 239); width: 105.85pt; border-width: medium 4.5pt 1.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;"><span style="color: black;">Used as initial planning for the TOBT until system, ATC or Pilot says otherwise.</span>

</td></tr><tr style="height: 28.25pt;"><td style="background: rgb(190, 245, 239); width: 42.05pt; border-width: medium 1.5pt 1.5pt 4.5pt; border-style: none solid solid; border-color: currentcolor windowtext windowtext; padding: 0cm 5.4pt; height: 28.25pt;">**TOBT**

</td><td style="background: rgb(190, 245, 239); width: 113.9pt; border-width: medium 1.5pt 1.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;">**T**<span style="color: rgb(192, 0, 0);">arget</span>

**O**<span style="color: rgb(192, 0, 0);">ff</span> **B**<span style="color: rgb(192, 0, 0);">lock</span> **T**<span style="color: rgb(192, 0, 0);">ime</span>

</td><td style="background: rgb(190, 245, 239); width: 184.75pt; border-width: medium 1.5pt 1.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;"><span style="color: black;">Time the pilot targets to be ready for Startup, depending on the loading process and pax delays</span>

</td><td style="background: rgb(190, 245, 239); width: 105.85pt; border-width: medium 4.5pt 1.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;"><span style="color: black;">Accepted via pilot EOBT. Can be modified by ATC, the Pilot, CTOTs or automatically by the system at any time.</span>

</td></tr><tr style="height: 28.25pt;"><td style="background: rgb(190, 245, 239); width: 42.05pt; border-width: medium 1.5pt 1.5pt 4.5pt; border-style: none solid solid; border-color: currentcolor windowtext windowtext; padding: 0cm 5.4pt; height: 28.25pt;">**TSAT**

</td><td style="background: rgb(190, 245, 239); width: 113.9pt; border-width: medium 1.5pt 1.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;">**T**<span style="color: rgb(192, 0, 0);">arget</span>

**S**<span style="color: rgb(192, 0, 0);">tart</span> **A**<span style="color: rgb(192, 0, 0);">pproval</span> **T**<span style="color: rgb(192, 0, 0);">ime</span>

</td><td style="background: rgb(190, 245, 239); width: 184.75pt; border-width: medium 1.5pt 1.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;"><span style="color: black;">Time the ATC targets to provide pilot with his startup, based on capacity restrictions at his TOBT</span>

</td><td style="background: rgb(190, 245, 239); width: 105.85pt; border-width: medium 4.5pt 1.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;"><span style="color: black;">Based on the filed TOBT, system will calculate the closest time to the TOBT that startup can be approved to respect all flow restrictions</span>

</td></tr><tr style="height: 28.25pt;"><td style="background: rgb(190, 245, 239); width: 42.05pt; border-width: medium 1.5pt 4.5pt 4.5pt; border-style: none solid solid; border-color: currentcolor windowtext windowtext; padding: 0cm 5.4pt; height: 28.25pt;">**CTOT**

</td><td style="background: rgb(190, 245, 239); width: 113.9pt; border-width: medium 1.5pt 4.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;">**C**<span style="color: rgb(192, 0, 0);">alculated</span>

**T**<span style="color: rgb(192, 0, 0);">ake-</span>**O**<span style="color: rgb(192, 0, 0);">ff</span> **T**<span style="color: rgb(192, 0, 0);">ime</span>

</td><td style="background: rgb(190, 245, 239); width: 184.75pt; border-width: medium 1.5pt 4.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;"><span style="color: black;">Time pilot must be “Takeoff” in order to respect a restriction en-route or at arrival field</span>

</td><td style="background: rgb(190, 245, 239); width: 105.85pt; border-width: medium 4.5pt 4.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;"><span style="color: black;">If a vIFF restriction en-route forces aircraft to be airborne in a certain time window a CTOT will be produced to ensure this.</span>

</td></tr><tr style="height: 28.25pt;"><td style="background: rgb(166, 166, 166); width: 42.05pt; border-width: medium 1.5pt 1.5pt 4.5pt; border-style: none solid solid; border-color: currentcolor windowtext windowtext; padding: 0cm 5.4pt; height: 28.25pt;">**ASAT**

</td><td style="background: rgb(166, 166, 166); width: 113.9pt; border-width: medium 1.5pt 1.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;">**A**<span style="color: rgb(59, 56, 56);">ctual</span>

**S**<span style="color: rgb(59, 56, 56);">tart</span> **A**<span style="color: rgb(59, 56, 56);">pproval</span> **T**<span style="color: rgb(59, 56, 56);">ime</span>

</td><td style="background: rgb(166, 166, 166); width: 184.75pt; border-width: medium 1.5pt 1.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;"><span style="color: rgb(59, 56, 56);">Actual time of Start.</span>

</td><td style="background: rgb(166, 166, 166); width: 105.85pt; border-width: medium 4.5pt 1.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;"><span style="color: rgb(59, 56, 56);">Locks the timings in vIFF</span>

</td></tr><tr style="height: 28.25pt;"><td style="background: rgb(166, 166, 166); width: 42.05pt; border-width: medium 1.5pt 1.5pt 4.5pt; border-style: none solid solid; border-color: currentcolor windowtext windowtext; padding: 0cm 5.4pt; height: 28.25pt;">**EXOT**

</td><td style="background: rgb(166, 166, 166); width: 113.9pt; border-width: medium 1.5pt 1.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;">**E**<span style="color: rgb(59, 56, 56);">stimated</span>

**T**<span style="color: rgb(59, 56, 56);">axi-</span>**O**<span style="color: rgb(59, 56, 56);">ut</span> **T**<span style="color: rgb(59, 56, 56);">ime</span>

</td><td style="background: rgb(166, 166, 166); width: 184.75pt; border-width: medium 1.5pt 1.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;"><span style="color: rgb(59, 56, 56);">Expected time between Start and Takeoff</span>

</td><td style="background: rgb(166, 166, 166); width: 105.85pt; border-width: medium 4.5pt 1.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;"><span style="color: rgb(59, 56, 56);">Standard timings based on gate</span>

</td></tr><tr style="height: 28.25pt;"><td style="background: rgb(166, 166, 166); width: 42.05pt; border-width: medium 1.5pt 4.5pt 4.5pt; border-style: none solid solid; border-color: currentcolor windowtext windowtext; padding: 0cm 5.4pt; height: 28.25pt;">**TTOT**

</td><td style="background: rgb(166, 166, 166); width: 113.9pt; border-width: medium 1.5pt 4.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;">**T**<span style="color: rgb(59, 56, 56);">arget</span>

**T**<span style="color: rgb(59, 56, 56);">ake-</span>**O**<span style="color: rgb(59, 56, 56);">ff</span> **T**<span style="color: rgb(59, 56, 56);">ime</span>

</td><td style="background: rgb(166, 166, 166); width: 184.75pt; border-width: medium 1.5pt 4.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;"><span style="color: rgb(59, 56, 56);">Expected Takeoff Time based on Taxi out time and TOBT.</span>

</td><td style="background: rgb(166, 166, 166); width: 105.85pt; border-width: medium 4.5pt 4.5pt medium; border-style: none solid solid none; border-color: currentcolor windowtext windowtext currentcolor; padding: 0cm 5.4pt; height: 28.25pt;"><span style="color: rgb(59, 56, 56);">Used to ensure an even departure rate</span>

</td></tr></tbody></table>

### 1.3 Flow Control Logic

Flow Control logic works through constant calculations. It is important that you understand the logic.

1. <span style="white-space: pre-wrap;">Pilot Logs onto VATSIM Network. In his Flightplan he has filed an </span>***EOBT***.
2. <span style="white-space: pre-wrap;">FS evaluates the validity of </span>***EOBT***<span style="white-space: pre-wrap;">, and assigns a </span>***TOBT***<span style="white-space: pre-wrap;">. </span>
3. <span style="white-space: pre-wrap;">A-CDM process begind. Based of the </span>***TOBT*** <span style="white-space: pre-wrap;">and available space in sequence a </span>***TSAT*** is "**calculated**"
4. <span style="white-space: pre-wrap;">The </span>***TSAT*** is send to vIFF servers for calculation.
5. <span style="white-space: pre-wrap;">vIFF servers used </span>***TSAT*** to calculate the routing to the destination, and if it exceeds ATC capacity anywhere
6. One of two things happen:
    1. - - <span style="white-space: pre-wrap;">a) No restrictions are identified, and </span>***TSAT*** is returned without edits to A-CDM.
            - <span style="white-space: pre-wrap;">b) Restrictions identified, </span>***CTOT*** produced to comply with restricionts and returned to A-CDM.
7. <span style="white-space: pre-wrap;">A-CDM either confirms the </span>***TSAT***, or calculates a new TSAT based on CTOT restriction
8. ***TSAT*** is "Assigned" to an aircraft.
9. <span style="white-space: pre-wrap;">If a </span>***TOBT*** <span style="white-space: pre-wrap;">is updated by either pilot or ATC, </span>**steps 3-8 are repeated.**

<p class="callout success">Refer to flowchart below for visual explanation</p>

[![Frame 7.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/EENframe-7.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/EENframe-7.png)

### <span style="color: rgb(35, 111, 161);">1.4 Calculation</span>

#### <u><span style="color: rgb(0, 0, 0);">1.4.1 A-CDM</span></u>

<span style="white-space: pre-wrap;">A-CDM needs to calculate a takeoff sequence. The core purpose is to only have as many departures an hour as the airport can handle, and nicely spread out. Therefore it is all based on TTOT (Target Takeoff Time). </span>

- In EKCH the capacity is 40flts/hr and therefore we have 40TTOT spots, spaced 1.5 minutes apart.

The calculation of A-CDM is as follows:

1. **EOBT** <span style="white-space: pre-wrap;">is recorded from flightplan, and based on that a </span>**TOBT** is assigned.
2. Stand is recorded and based on RWY in use, a EXOT is established. TOBT+EXOT = TTOT
    1. 1. - - <span style="white-space: pre-wrap;">Example: TOBT: 1435z. EXOT 12min; 1435z+00:12min = </span>**TTOT=1447z**
3. The system then compares the TTOT to available TTOTs and does one of two things:
    1. - TTOT available: TSAT issued at TOBT
            - - <span style="white-space: pre-wrap;">Example: TTOT: 1447z available, EXOT 12min. 1447z-00:12min = </span>**TSAT=1435z**
        - TTOT occupied: Find next available TTOT, calculate back EXOT, which becomes TSAT
            - - Example: TTOT: 1453z first available, exit 12min. 1453z-00:12min = TSAT=**1441z**
4. <span style="white-space: pre-wrap;">TSAT assigned to optimize traffic flow depending on what TTOT is available. </span>

#### <u><span style="color: rgb(0, 0, 0);">1.4.1 vIFF - CDM</span></u>

vIFF does NOT care about our internal capacity. Only about:

- Enroute Sector capacity
- Arrival TMA capacity
- Arrival Airport capacity
- ECFMP special restrictions

vIFF knows the EXOT of EKCH.

1. <span style="white-space: pre-wrap;">TSAT which was determined by A-CDM is send to vIFF. </span>
2. vIFF, uses TSAT+EXOT to determine TTOT, and afterwards a 3D routing through all airspaces
3. If a sector capacity does not allow the flight it will assign a CTOT at a time the capacity allows.
4. CTOT is send back to A-CDM
5. <span style="white-space: pre-wrap;">A-CDM produces a TSAT to fit that CTOT, overriding all other A-CDM restrictions, and delaying subsequent aircrafts TTOT. </span>

</details>[![Group 435.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/ahqgroup-435.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/ahqgroup-435.png)

[![CDM Layout.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/Uf6cdm-layout.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/Uf6cdm-layout.png)There are two different kinds of layout of CDM. They are similar in colorcoding but differently build up.

- **SEQ PLN, AA+AD** <span style="white-space: pre-wrap;">(or </span>**APRON DEP**<span style="white-space: pre-wrap;">), </span>**GND + TWR**
    - Controlled using conventional FlightStrips techniques
- **EST Scope**
    - Controlled using EST Scope technique.

[![Rectangle 324.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/WNYrectangle-324.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/WNYrectangle-324.png)

### <span style="color: rgb(35, 111, 161);">2.1 CDM Design on Strips</span>

[![image.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/Igsimage.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/Igsimage.png)

<p class="callout warning"><span style="color: rgb(0, 0, 0); white-space: pre-wrap;">CDM operation IS </span><u>**NOT**</u><span style="color: rgb(0, 0, 0); white-space: pre-wrap;"> possible from the CLR DEL scope. CLR DEL must use the </span>**SEQ PLN**<span style="color: rgb(0, 0, 0); white-space: pre-wrap;"> scope.</span></p>

<span style="color: rgb(0, 0, 0); white-space: pre-wrap;">CDM operation is accomplished via the STARTUP bay in conventional FlightStrips scopes. Aircrafts are sorted with earliest TSAT in bottom. </span>

<details id="bkmrk-cdm-design-on-strips"><summary>CDM Design on Strips</summary>

#### **2.1.1 Unrestricted Strips**

<span style="color: rgb(0, 0, 0);">An unrestricted aircraft will not have any color codes until its start-up window.</span>

[![Group 271.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/group-271.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/group-271.png)

---

#### **2.1.2 Startup Approved Strips**

<span style="color: rgb(0, 0, 0);">An aircraft which h</span>as reached its startup window will show a green TSAT. Start-up may be approved.

[![Group 347.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/group-347.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/group-347.png)

<details><summary>TSAT Sequence</summary>

<span style="white-space: pre-wrap;">Start-up window may include a CTOT, but TSAT will still indicate green. </span>

[![Group 343.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/group-343.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/group-343.png)

<span style="white-space: pre-wrap;">When a TSAT is one (1) minute from expiring, TSAT will indicate Yellow. </span>

[![Group 343-2.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/group-343-2.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/group-343-2.png)

When TSAT is expired, TSAT coloring will disappear and a Red TOBT appears.

[![-3.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/3.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/3.png)

<u>**New TOBT must be filed**</u>

</details>---

#### **2.1.3 A-CDM Delayed Strips**

<span style="color: rgb(0, 0, 0); white-space: pre-wrap;">An aircraft which has been delayed by A-CDM due to RWY capacity, will show an </span><span style="color: rgb(0, 0, 0); background-color: rgb(230, 126, 35);">Orange TOBT</span><span style="color: rgb(0, 0, 0); white-space: pre-wrap;"> indicating a &gt;5min delay between the TOBT and TSAT.</span>

[![Group 342.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/group-342.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/group-342.png)

- When within startup window TSAT will turn green

---

#### **2.1.4 vIFF Delayed Strips**

<span style="color: rgb(0, 0, 0); white-space: pre-wrap;">An aircraft which has been delayed by VIFF due to EU capacity, will show an </span><span style="color: rgb(0, 0, 0); background-color: rgb(241, 196, 15);">Yellow CTOT</span><span style="color: rgb(0, 0, 0); white-space: pre-wrap;"> to warn controllers. The CTOT may or may not also be accompanied by an </span><span style="color: rgb(0, 0, 0); background-color: rgb(230, 126, 35); white-space: pre-wrap;">Orange TOBT </span><span style="color: rgb(0, 0, 0);">if the CTOT results in a &gt;5min delay from TOBT</span>

[![Group 345.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/group-345.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/group-345.png)

- When within startup window TSAT will turn green

</details>---

[![Rectangle 324.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/Rnyrectangle-324.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/Rnyrectangle-324.png)

### <span style="color: rgb(35, 111, 161);">2.2 CDM Design on EST</span>

[![image.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/tYeimage.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/tYeimage.png)

<span style="white-space: pre-wrap;">EST Scope has a different layout as it is an image of all the stands. It will show for each individual stand the same color codes as the regular scopes. </span>

<details id="bkmrk-cdm-design-on-est2.1"><summary>CDM Design on EST</summary>

#### **2.1.1 Unrestricted Strips**

<span style="color: rgb(0, 0, 0);">An unrestricted aircraft will not have any color codes until its start-up window.</span>

[![CLEARED (NON RDY).png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/cleared-non-rdy.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/cleared-non-rdy.png)

---

#### **2.1.1 Startup Approved Strips**

<span style="color: rgb(0, 0, 0);">An aircraft which h</span>as reached its startup window will show a green TSAT &amp; TOBT. Start-up may be approved.

[![CLEARED (NON RDY) 2.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/cleared-non-rdy-2.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/cleared-non-rdy-2.png)

<details><summary></summary>

<span style="white-space: pre-wrap;">Start-up window may include a CTOT, but TSAT will still indicate green. </span>

[![10.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/10.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/10.png)

<span style="white-space: pre-wrap;">When a TSAT is one (1) minute from expiring, TSAT will indicate Yellow. </span>

[![CLEARED (NON RDY)3.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/1bNcleared-non-rdy3.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/1bNcleared-non-rdy3.png)

When TSAT is expired, TSAT coloring will disappear and a Red TOBT appears.

[![4.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/4.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/4.png)

<u>**New TOBT must be filed**</u>

</details>---

#### **2.1.1 A-CDM Delayed Strips**

<span style="color: rgb(0, 0, 0); white-space: pre-wrap;">An aircraft which has been delayed by A-CDM due to RWY capacity, will show an </span><span style="color: rgb(0, 0, 0); background-color: rgb(230, 126, 35);">Orange TOBT</span><span style="color: rgb(0, 0, 0); white-space: pre-wrap;"> indicating a &gt;5min delay between the TOBT and TSAT.</span>

[![11.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/11.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/11.png)

- When within startup window TSAT will turn green

---

#### **2.1.1 vIFF Delayed Strips**

<span style="color: rgb(0, 0, 0); white-space: pre-wrap;">An aircraft which has been delayed by VIFF due to EU capacity, will show an </span><span style="color: rgb(0, 0, 0); background-color: rgb(241, 196, 15);">Yellow CTOT</span><span style="color: rgb(0, 0, 0); white-space: pre-wrap;"> to warn controllers. The CTOT may or may not also be accompanied by an </span><span style="color: rgb(0, 0, 0); background-color: rgb(230, 126, 35); white-space: pre-wrap;">Orange TOBT </span><span style="color: rgb(0, 0, 0);">if the CTOT results in a &gt;5min delay from TOBT.</span>

<span style="color: rgb(0, 0, 0);">A CTOT which has had an improvement will show in Dark Blue to alert controller of an improvement</span>

[![image.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/Z4Cimage.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/Z4Cimage.png)

- When within startup window TSAT will turn green

</details>[![Group 435.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/WSRgroup-435.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/WSRgroup-435.png)

[![CDM Procedures.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/cdm-procedures.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/cdm-procedures.png)

This chapter is about what procedures you must adhere to when managing CDM. You have learned the philosphy and how it looks, now you need to know how to use it. Its developed into 4 subchapters:

- Timings
- EST procedures
- SEQ PLN procedures
- AA+AD procedures

### <span style="color: rgb(35, 111, 161);">3.1 Acceptable Timing</span>

CDM procedures varies from Apron (and DEL) and Towers.

- <span style="white-space: pre-wrap;">GND/DEL prime concern is to ensure Aircraft starts in accordance with </span>**TSAT**
- <span style="white-space: pre-wrap;">TWR prime concern is to ensure Aircraft takes off in accordnace with </span>**CTOT**

By following the guidelines of Chapter 3 - FlightStrips CDM operation, controller shall adhere to following timings:

- <span style="color: rgb(230, 126, 35);">GND/DEL</span><span style="white-space: pre-wrap;">: Start-up approval within </span><u>-5 min until +5min</u><span style="white-space: pre-wrap;"> of </span>**TSAT**.
- <span style="color: rgb(186, 55, 42);">TWR</span><span style="white-space: pre-wrap;">: Takeoff commenced within </span><u>-5min until +10min</u><span style="white-space: pre-wrap;"> of </span>**CTOT**

<p class="callout warning"><span style="white-space: pre-wrap;">Outside of </span>**TSAT+6**<span style="white-space: pre-wrap;"> a new TOBT must be requested</span></p>

<p class="callout danger"><span style="white-space: pre-wrap;">Outside of </span>**CTOT+11** TWR should consider severity of exceedance, and allow aircraft to depart only if deemed safe and responsibly to do so by judgement of controller.</p>

[![Rectangle 324.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/fugrectangle-324.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/fugrectangle-324.png)

### <span style="color: rgb(35, 111, 161);">3.2 EST Scope Procedures</span>

<span style="color: rgb(0, 0, 0);">On EST Screen, clicking on an aircraft on a stand, the menu appears with several different options</span>

[![image.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/niQimage.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/niQimage.png)

- **START REQ + TRF**
- **START REQ**

Which one you need is dependent on the situation of the aircraft. The visual action is similar, but what goes on behind the scenes are different.

<details id="bkmrk-start-req-%2B-trfstart-1"><summary>START REQ + TRF</summary>

#### **START REQ + TRF**

<u><span style="white-space: pre-wrap;">Only </span></u>available when aircraft is WITHIN TSAT Window. It performs following actions

- Approves the aircraft for startup by assigning ASAT, locking the CDM.
- Transfers the strip automatically over to APRON
- Changes appearance to a dark blue color labelled READY above. TOBT &amp; TSAT removed.

[![16.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/16.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/16.png)

</details><details id="bkmrk-start-reqstart-req-a"><summary>START REQ</summary>

#### **START REQ** 

<span style="white-space: pre-wrap;">Available if aircraft reports ready </span><u><span style="white-space: pre-wrap;">before </span></u>the TSAT window. It performs following actions:

- Selects TOBT to current time in order to look for an earlier TSAT.
- <span style="white-space: pre-wrap;">Changes appearance to dark blue color labelled READY above. </span>
- Orange outline, until within TSAT window, then changing to green outline.

[![image.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/7VJimage.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/7VJimage.png)

START REQ can be used for:

- TSAT not yet within window. looking for an earlier TSAT
- TSAT expired. Resetting TOBT to find new TSAT
- RDY MSG send by pilot. Will look for an earlier CTOT.

If a START REQ results in a new TSAT found within the window, START REQ + TRF must subsequently be pushed.

<p class="callout info"><span style="white-space: pre-wrap;">START REQ will not look for a new TSAT if current TSAT is within 10min </span>**AND** has a CTOT attached to it.</p>

</details><details id="bkmrk-other-buttonsother-b"><summary>OTHER BUTTONS</summary>

#### **Other Buttons**

[![image.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/2f6image.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/2f6image.png)

<span style="white-space: pre-wrap;">Two additional buttons called </span>**PUSH** <span style="white-space: pre-wrap;">and </span>**TAXI** <span style="white-space: pre-wrap;">is also available. This does the same as </span>**START REQ+TRF**<span style="white-space: pre-wrap;">, but instead of transfering it automatically moves them directly to </span>**PUSHBACK** <span style="white-space: pre-wrap;">and </span>**TWY DEP**<span style="white-space: pre-wrap;"> bay respectively.</span>

Useful for when using EST screen, while sitting on a GND or TWR position.

</details>[![Rectangle 324.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/DFArectangle-324.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/DFArectangle-324.png)

### <span style="color: rgb(35, 111, 161);">3.3 SEQ PLN Procedures</span>

<span style="color: rgb(0, 0, 0);">On SEQ PLN scope, o</span><span style="white-space: pre-wrap;">n the strip there are only one click spot you can use. </span>

[![image.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/4rrimage.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/4rrimage.png)

<span style="white-space: pre-wrap;">Clicking on TOBT field, will do the same as START REQ does on the EST scope. It will set TOBT to current time and allow an earlier TSAT to be found. Can be used for: </span>

- TSAT not yet within window. looking for an earlier TSAT
- TSAT expired. Resetting TOBT to find new TSAT
- RDY MSG send by pilot. Will look for an earlier CTOT.

<span style="white-space: pre-wrap;">If an earlier TSAT is found, TSAT and TOBT will light up green and start-up can be approved. </span>

[![Group 3471.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/group-3471.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/group-3471.png)

Transfer must be done by clicking on the SI Field indicator to commence transfer.

<p class="callout warning"><span style="white-space: pre-wrap;">Transfer via SI field will </span><u>**NOT**</u><span style="white-space: pre-wrap;"> work outside of TSAT window. Manual transfer only in case of CDM malfunction</span></p>

<p class="callout info"><span style="white-space: pre-wrap;">TSAT click spot will not look for a new TSAT if current TSAT is within 10min </span>**AND** has a CTOT attached to it.</p>

[![Rectangle 324.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/hWyrectangle-324.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/hWyrectangle-324.png)

### <span style="color: rgb(35, 111, 161);">3.4 AA+AD / GND+TWR Procedures</span>

<span style="color: rgb(0, 0, 0);">On AA+AD (And GND+TWR), Strips have a different layout and only displays TSAT and CTOT</span>

[![image.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/w8Uimage.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/w8Uimage.png)

##### **NOTE: In above example CTOT is also present**

Clicking on TSAT field, will set TOBT to current time and look for a new TSAT. Can be used for:

- TSAT not yet within window. looking for an earlier TSAT
- TSAT expired. Resetting TOBT to find new TSAT
- RDY MSG send by pilot. Will look for an earlier CTOT.

<span style="white-space: pre-wrap;">If an earlier TSAT is found, TSAT will light up green and start-up can be approved. </span>

[![FINAL 2.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/final-2.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/final-2.png)

##### **NOTE: In above example CTOT is improved and shows in Blue.**

Aircraft can then be transfered into PUSHBACK bay by standard procedures.

<p class="callout warning"><span style="white-space: pre-wrap;">If aircraft is positioned in </span>**PUSHBACK** <span style="white-space: pre-wrap;">or </span>**TWY DEP**<span style="white-space: pre-wrap;"> bay before TSAT window, the TOBT will automatically be set to current time, and earliest TSAT assigned. </span></p>

<p class="callout warning">Failure of system to find an earlier TSAT will result in a "**Validation status**<span style="white-space: pre-wrap;">", warning controller. </span></p>

[![Frame 47.png](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/scaled-1680-/frame-47.png)](https://wiki.vatsim-scandinavia.org/uploads/images/gallery/2026-09/frame-47.png)

<p class="callout success">Controller must delay pushback/taxi/takeoff or override to serve delay at holding point</p>