Jetway Helpers

MSFS 2024 docks a jetway only to an aircraft in its ATC parking table. Injected traffic is NonATC, and no SimConnect call, event or variable docks a jetway to it. What works is an invisible ParkedATC helper aircraft with the door of the right type, created on the gate under the parked aircraft: the simulator docks the gate’s jetway to the helper, and so to the door of the aircraft standing there. pkg/jetway writes the helper models and runs them.

This page is the library level. How the traffic World uses it (placeholders at start-up, docking on arrival, undocking before the push, retries and gate rest) is on Jetways at Gates.

The helper package

WritePackage writes a Community package with one invisible helper SimObject per type (a model with no LODs, parked at gates only), copying the base model’s flight_model.cfg, engines.cfg, systems.cfg and ai.cfg so the helper’s door (interactive_point.0) is that type’s. The simulator reads it at its next start.

dir, err := jetway.WritePackage(community, []jetway.HelperModel{
    {Type: "A320", Dir: `...\SimObjects\Airplanes\A320`},
}, jetway.PackageOptions{SideSteps: 6, SideStepM: 0.1, AheadM: []float64{-9}})

`PackageOptions`
`Folder`, `Version`, `Creator`	the package’s folder (`mycrew-jetway-helper`), version (`0.1.0`) and manifest creator
`Codes`	airline codes for each type’s second helper (`… ALL`); none: only the helper without codes
`WingSpanFt`	replaces every helper’s wing span (the simulator puts no ParkedATC next to an occupied gate)
`SideSteps`, `SideStepM`	door variants `SideStepM × k` to the right, `k` from `-SideSteps` to `SideSteps`, for gates where the simulator parks off the line (`HelperVariantTitle`)
`AheadM`	door variants moved along the fuselage, for stands where our aircraft stops off the simulator’s place, such as the stand rules’ offsets (`HelperAheadTitle`)

Every helper’s title starts with HelperTitlePrefix ("MyCrew Jetway Helper "); IsHelper and IsHelperVariant recognise them, so lists can leave them out and traffic never uses them as a model. The jetway-helpers example writes the package from the installed traffic models (-types, -codes, -span, -side-steps, -side-step, -ahead).

Service and the Helpers backend

The engine talks to a Service; with none, or one not Available, traffic parks and pushes as without jetways. Helpers is today’s backend; a direct API, once the simulator has one, would be another behind the same calls.

svc := jetway.NewHelpers(client, jetway.HelperOptions{
    Types:       []string{"A320", "B738"}, // types in the installed package
    RetractPlan: retractPlanFor,           // a .pln out of icao for the placeholders
    RequestBase: 43200,                    // 1000 request IDs from here
    AircraftAt:  ourAircraftOn,            // our parked aircraft on a stand, 0 none
})
svc.Prepare("LKPR")            // fill the jetway gates with placeholders
svc.Dock("LKPR", 14, "A320")   // our A320 parked on stand index 14
svc.Undock("LKPR", 14)         // before the push
st := svc.Status("LKPR", 14)   // reserved, docking, docked, undocking, failed
// in the message loop and every frame or so:
svc.Handle(msg)
svc.Update(time.Now())

Method
`Available()`	whether the backend can work here, and why not
`Prepare(icao)` / `Release(icao)`	ask for the airport’s jetways and fill its gates with placeholders, one at a time; release removes every placeholder and helper and sends the jetways home
`Dock(icao, stand, model)` / `DockAs(…, title)`	take the stand’s placeholder away and create the helper of the model’s type (or a given variant): the simulator gives it the one free gate and its jetway docks
`Undock(icao, stand)`	send the jetway home; a docked helper stays as the gate’s placeholder (given the retract plan, released `RetractWait` later) so the simulator cannot hand the gate to anything else
`Status`, `Since`	a stand’s jetway now, and when that last changed
`Dockable(icao)`, `Filling(icao)`, `HasJetway`	gates a helper can be given now (about every other jetway gate: no ParkedATC next to an occupied one), whether the gates are still being filled
`HelperFor(model)`, `Types()`	the helper title a model docks with, the types the package has

Timings, measured live: RetractWait 25 s, ClaimTimeout 12 s for a placeholder no jetway takes, EmptyFillTries 25 while the simulator still loads the airport, RefillEvery 2 min, DockSettle 2 min between docks, DockTimeout 90 s, HelperDelay 3 s between a placeholder leaving and its helper arriving.

Door offsets

Where a jetway meets the visible door differs by type: the jetway docks to the helper, not to our aircraft. DoorOffset (metres ahead and right) per type moves the helper so the jetway meets our door; DoorOffsetFor(model) finds the longest type a model or title contains. The table is jetway.doorOffsets in Dictionaries, replaceable at runtime; none are shipped yet. HelperOptions.Offset gives the host’s own computation, and MoveHelpers turns on actually moving the helper (off by default: live, a helper moved after the simulator placed it reported docked without the jetway moving).

HelperOptions.OnPlaceholder tells the host where the simulator parked each placeholder or helper on its gate, so the host can park its own aircraft the same way.