Build a KLAX to RKSI flight plan with the right Pacific route, aircraft, fuel, ETOPS alternates, FMC checks and Incheon arrival.
To plan KLAX to RKSI in a general flight simulator, use a long-range airliner, generate a date-specific, wind-optimised North Pacific route, and match the KLAX SID and RKSI STAR to the expected runways. Then verify every FMC leg, plan suitable en-route and destination alternates, and carry contingency, alternate and final-reserve fuel.
What route should you use from KLAX to RKSI?
Use a planner-generated Pacific corridor rather than a permanently copied route string. This applies to Microsoft Flight Simulator, X-Plane, Prepar3D and FSX; the precise route depends on winds, organised-track availability, airspace restrictions and the navigation-data cycle installed in the aircraft.
A practical route shape is KLAX – SID – North Pacific entry – PACOTS or flexible oceanic segment – Japan/Korea gateway – RKSI STAR – approach. On a flat map it will normally arc north across the Pacific rather than follow a straight westward line.
| Routing method | Choose it when | Main caveat |
|---|---|---|
| PACOTS | A published Pacific Organised Track suits the winds and planned crossing time | Tracks change with date and time; the FMS may require the underlying fixes or coordinates rather than a track label |
| Fixed NOPAC airways | You want a repeatable route or are using older simulator navigation data | The route can be longer and less wind-efficient |
| Flexible or user-preferred route | Your planner and ATC environment support wind-optimised routing | Every coordinate, FIR crossing and airspace segment needs careful checking |
KLAX to RKSI is roughly 5,200 NM by great-circle distance, with the operational route usually longer. A modern widebody commonly needs around 12–14 hours, but the planned wind, aircraft profile and route distance are more useful than a fixed time estimate.
How do you build the KLAX to RKSI flight plan?
Build the plan in a fixed order so that a late runway or weather change does not invalidate the whole route.
- Select the exact aircraft variant. Match the planner profile to the add-on you will fly, including engine option where available. Payload, fuel burn and maximum weights can differ substantially between variants of the same aircraft family.
- Set the departure date and UTC time. Upper winds and PACOTS availability are time-dependent. Check track validity at the estimated oceanic entry time, not just the KLAX departure time.
- Generate the operational flight plan. Our guide to building a complete SimBrief plan with payload, fuel and weather explains the fields and aircraft-profile choices. Prefer a route generated for the flight date over one copied from an old dispatch record.
- Inspect the route on a map. Look for loops, sharp turns, reversed coordinates and implausible shortcuts. The route should remain clear of unintended restricted airspace and should join the Korean arrival structure sensibly.
- Add runway procedures last. Select a KLAX SID compatible with the actual airport flow and first en-route fix. At RKSI, choose the STAR transition, runway and approach from the arrival weather; our explanation of reading SIDs, STARs and approach plates covers the restrictions that must be checked.
- Calculate fuel and alternates. Include taxi, trip, contingency, destination-alternate, final-reserve and any operational extra fuel. For a twin-engined aircraft, also review ETOPS/EDTO coverage along the selected track.
- Load the FMS carefully. Import the correct format or enter the route manually, then use the FMC/MCDU import and leg-check procedure to resolve genuine errors without deleting valid vector legs.
- Compare the programmed route with the plan. Total distance, first and last oceanic fixes, destination, runway and predicted arrival fuel should agree. Review the route in PLAN mode before departure.
Which aircraft should you choose, and how long will it take?
A long-range widebody is the normal choice for KLAX–RKSI. Boeing 777, 787 and 747 variants, and suitable Airbus A330 or A350 variants, can make the sector when correctly loaded, but the simulated aircraft's actual performance model is what matters.
- Modern long-range widebody: the simplest choice, with comfortable range and realistic airline operations.
- Older or shorter-range widebody: use it only when the plan shows acceptable take-off weight and landing reserve after westbound winds are included.
- Narrowbody or business aircraft: verify the exact variant's practical range rather than brochure range. A fuel stop is often more credible than reducing reserves or inventing an unrealistic payload.
Do not set maximum fuel automatically. Unnecessary fuel adds weight, raises take-off requirements and causes additional fuel burn. If range, step climbs or reserves are unfamiliar, our long-haul range, cruise and reserve workflow covers those calculations in more depth.
The flight crosses the International Date Line, so the local arrival date may not match the departure date. Keep the plan, weather and track validity in UTC to avoid loading conditions for the wrong day.
How much fuel and which alternates should you plan?
Use aircraft-specific dispatch figures rather than a generic fuel quantity for the route. The required load changes with payload, engine model, planned altitude, wind and the distance to suitable alternates.
- Trip fuel covers take-off through landing on the planned route.
- Contingency fuel protects against forecasting and performance differences.
- Alternate fuel covers a missed approach, diversion and landing at the nominated destination alternate.
- Final reserve remains protected unless an emergency requires it.
- Extra fuel may be justified by holding, poor destination weather, runway closures or uncertainty in the aircraft's simulated fuel burn.
For ETOPS/EDTO planning, select adequate en-route airports along the actual track and verify their weather, runway length, approaches and availability. The nearest airport symbol is not automatically a suitable widebody alternate.
Near Seoul, RKSS or RKTU may appear as destination-alternate candidates, but neither should be selected blindly. Check landing performance, forecast weather, approach availability and whether the airport is represented properly in the simulator scenery and navigation database.
Why does an imported Pacific route fail in the FMC?
Most broken KLAX–RKSI imports come from mismatched navigation data, coordinate formatting or duplicated procedures rather than a faulty autopilot.
- Missing waypoint or airway: the planner and aircraft are using different AIRAC cycles. Generate against the aircraft's cycle where possible, or rebuild the affected segment using valid fixes and charts.
- Oceanic leg points the wrong way: a latitude or longitude was translated into the wrong FMC format. Enter the coordinates exactly as required by that aircraft and confirm each point on the map.
- The track cannot be loaded: many FMS databases do not store a temporary PACOTS identifier. Enter or import the published fixes and coordinates that define the track.
- Loop or duplicate waypoint near KLAX or RKSI: the exported route already contains a procedure transition and another was added manually. Remove the duplicate, not the entire procedure.
- Runway or STAR is missing: the scenery, simulator and aircraft navdata may represent different airport revisions. Use a procedure supported by the installed data, or align the scenery and navdata before flying.
- Discontinuity after a vector leg: this can be intentional. Do not connect every discontinuity automatically; first confirm whether the chart expects radar vectors or a manual intercept.
What should you check during the flight and before descent?
Compare actual fuel against planned fuel at major waypoints and before committing to the oceanic segment. If the deficit is growing, check winds, cruise level, aircraft weight and engine settings rather than assuming the destination prediction will recover.
Make step climbs only when the FMS optimum and maximum altitudes support them. Well before top of descent, obtain the RKSI weather, select the correct STAR and approach, brief every altitude and speed restriction, and confirm that predicted landing fuel still exceeds the protected reserve.
If online ATC assigns a different route, runway or arrival, its clearance replaces the planner's assumption. Amend the FMS deliberately and recheck the join between the oceanic route, arrival transition and approach before allowing LNAV to follow it.