How do SIDs and STARs work with ATC in a flight simulator?

In Aviation & Real-World Flying, ATC may clear a SID for departure and a STAR for arrival, then replace either with vectors, a direct-to instruction or a runway change. Load the exact cleared procedure and transition, verify its legs and constraints, and follow the latest clearance whenever it differs from the FMS route.

What do SID and STAR mean in aviation and ATC?

A SID, or Standard Instrument Departure, connects a departure runway with the en-route structure; a STAR, or Standard Terminal Arrival Route, brings an aircraft from the en-route structure into the destination terminal area.

Both may contain runway branches, transitions, named fixes, altitude restrictions and speed constraints. They reduce the amount of route information ATC must read over the radio, but they do not remove the need for an altitude clearance or later amendments. Our explanation of how pilots select, brief and fly each procedure covers the underlying route structure.

Here, SID is strictly the aviation term. It is unrelated to medical SIDS news or similarly named subjects.

What exactly does ATC clear on a SID or STAR?

ATC clears a route and, separately or through recognised regional phraseology, the levels and speeds that apply to it.

A filed flight plan is a request rather than permission to fly every entered leg. ATC can accept the requested SID or STAR, assign another one, issue radar vectors, clear the aircraft directly to a later fix or change the runway. The wording varies by country and by the ATC implementation in the simulator.

An explicit heading, direct-to, altitude or speed instruction changes the corresponding part of the earlier clearance. It does not necessarily cancel every other published restriction. If the wording is ambiguous, ask ATC for clarification rather than guessing what remains in force.

How do you load the same SID or STAR for ATC?

The route available to ATC and the route loaded in the cockpit must describe the same intended flight.

1. Identify which flight plan ATC reads. Built-in ATC often follows the plan filed through the simulator, while an aircraft's FMS may hold a separate copy. Live or add-on ATC may use an imported plan instead.
2. Choose a suitable candidate. Runway, route direction, transition, aircraft capability and local restrictions determine the sensible procedure; the shortest-looking line is not always valid. Use our procedure-selection checklist before filing it.
3. Copy the complete clearance. Record the runway, procedure name, en-route transition, initial altitude and any amendment. For an arrival, distinguish the STAR, runway branch and instrument approach.
4. Load the procedure through the avionics. Select it from the FMS, MCDU or GPS database where possible instead of manually typing every waypoint.
5. Inspect the legs page against the chart. Check the first fix, transition, en-route join, turn direction, altitude restrictions and speed constraints. Our chart-reading guide for fixes, transitions and constraints explains what to compare.
6. Resolve only genuine errors. Remove duplicate fixes and unintended loops, but retain a vector discontinuity when the chart or clearance expects radar headings.
7. Apply amendments before re-engaging automation. After a runway, transition or direct-to change, verify the active leg and predicted path before selecting LNAV, VNAV or approach mode.

A mismatch we see often is filing one procedure in the simulator planner and entering another directly into the aircraft. Microsoft Flight Simulator 2020 and 2024 can leave built-in ATC tied to the simulator-level route even when a sophisticated add-on aircraft has been reprogrammed only through its cockpit.

Why do ATC and the FMS disagree?

ATC/FMS disagreements usually come from separate route copies, different navigation-data revisions or a runway change applied to only part of the flight plan.

• Separate flight plans: ATC is tracking the filed simulator route while the aircraft follows later FMS edits. Amend or refile the ATC-facing plan where the system permits it.
• Different navigation data: the simulator, aircraft and ATC engine may not contain the same revision of a procedure. A renamed SID, missing transition or changed runway identifier is a strong clue.
• Wrong transition: matching the procedure name is insufficient when it has several entry or exit points. Compare the cleared transition with the actual legs.
• Partial runway change: changing the approach without reloading the STAR can leave the old runway branch, duplicate fixes or a route back across the airport.
• Intentional vector leg: some arrivals end in vectors to final. Closing that discontinuity can make the aircraft turn towards the approach before ATC has cleared it.
• Duplicate waypoint names: a Direct-To command can select a similarly named fix in another part of the route. Confirm its position and the resulting track before execution.
• ATC limitations: scripted ATC may assign late descents, unsuitable runways or instructions that ignore aircraft performance. Request an alternative where possible and go around if a stable approach cannot be achieved.

What if ATC assigns a SID or STAR that is missing from the FMS?

Do not substitute a similarly named procedure without checking its chart and route.

If the avionics effectively reports такого нету — Russian for “there is no such one” — check the airport identifier, runway, procedure spelling, transition and navigation-data source. The airport may genuinely have no published SID or STAR, especially at a smaller aerodrome. With live ATC, report that you are unable to accept the procedure and request vectors or another clearance; with built-in ATC, use a route recognised by both systems.

What do DBY or DBYJAATHC mean in an ATC route?

Neither DBY nor DBYJAATHC is a standard generic ATC command for flying a SID or STAR.

A short code such as DBY could be an airport, fix, operator or local database identifier in a particular context. A longer unexplained string may be concatenated, corrupted or mistyped. Compare it with the filed route, chart and FMS waypoint list rather than inventing an aviation meaning for it.

Does ATC fly the SID or STAR for you?

No; ATC assigns or approves the route, while the pilot flies it manually or through the aircraft's automation.

LNAV normally follows the lateral legs. VNAV may calculate a climb or descent through published restrictions, but not every simulated aircraft has working VNAV, and even advanced systems can miss constraints after a route edit. Monitor the flight-mode annunciator, selected altitude, vertical path and next restriction.

When ATC assigns a heading, use heading mode instead of allowing LNAV to continue along the procedure. After a direct-to or an instruction to rejoin, confirm the active leg and intercept geometry before returning to LNAV.

Is a STAR the same as an approach?

No; a STAR leads into the terminal area, while an instrument approach provides a defined route towards a runway or missed-approach point.

The two may connect at a common fix, but ATC can vector the aircraft off the STAR and intercept the approach elsewhere. Clearance for a STAR is not, by itself, clearance for the approach or permission to land.

Which flight plan matters for ATC?

For ATC, the controlling route is the one received by that particular controller or ATC engine, not necessarily the route visible on the aircraft's primary display.

What should you do after an ATC runway change?

Reload the affected procedure and inspect the whole terminal route, because changing the runway field alone can leave obsolete legs and constraints behind.

1. Confirm the amendment, including the runway, SID or STAR, transition and expected approach.
2. Reload the relevant procedure rather than editing isolated fixes unless the avionics requires manual changes.
3. Check the entire revised path for loops, duplicated waypoints, old runway branches and unexpected discontinuities.
4. Verify the active leg and modes before selecting Direct-To, LNAV, VNAV or approach mode.
5. Reassess the vertical profile. If there is insufficient distance for a stable approach, request delay vectors, accept a hold only when cleared, or go around.

Are SID and STAR updates published as simulator news?

No; operational SID and STAR revisions are distributed through controlled charts and navigation-data updates, not ordinary simulator news.

General flight-simulation news may report changes to an aircraft, airport or navigation-data service, but it is not the authority for a procedure. Two databases from different update cycles can contain different names, transitions or runway branches even though both appear to cover the same airport.

Do you need freeware to use SIDs and STARs?

No; you need compatible avionics, suitable procedure data and an aircraft capable of flying the required route.

Freeware aircraft, airport scenery and ATC add-ons can improve the simulation, and suitable packages can be found in our freeware aircraft, scenery and add-on library. Check simulator and platform compatibility, the avionics used and the package's navigation-data assumptions before installing anything. Airport scenery alone normally does not add a missing procedure to the FMS database.