Aircraft Profiles and Telemetry

Speeds, distances and attitudes differ per aircraft type. pkg/traffic bundles every per-type figure injected traffic uses into an AircraftProfile:

Resolving a profile

p := traffic.ProfileFor("FSLTL B77W Emirates") // p.Type == "B77W", p.ICAOCode == 'E'
p = traffic.ProfileFor("ATCCOM.AC_MODEL A319.0.text") // ATC MODEL works too

ProfileFor matches the container title, the ATC MODEL or a type designator against the known types, the most specific first: A20N, A320, A321, A21N, A319, B738, B38M, B739, B39M, B737, B77W, B77L, B772, B789, B788, B78X, A332, A333, A359, A35K, A388, B744, B748, E175, E190, E195, CRJ9, AT76 and DH8D (KnownTypes()). The figures are published values (span, length, wheelbase, final approach speed, Vr, take-off distance) and typical ones for what the simulator does not expose (pitch attitudes, flare, taxi speeds).

Unknown titles get DefaultAircraftProfile() — the A320 family figures every default in the package stands for (DefaultMotionProfile, DefaultTakeoffProfile, DefaultApproachProfile, DefaultRolloutProfile, DefaultNoseOffsetMeters, the flap tunables). GenericProfile(span, category) picks a representative type by size and scales its airframe.

WakeFor(type) takes the same titles and designators and gives the type’s wake categories for spacing in the air (Airborne Separation).

Requests

TaxiRequest and ArrivalRequest have an Aircraft *AircraftProfile. nil resolves it from Model. The profile fills Profile, Takeoff, Approach, Rollout and NoseOffset where those are zero, so figures set explicitly still win and existing callers keep working. The controllers take the flaps, pushback speed, logo light, spawn height and the turn-around loop size from it.

ac := traffic.ProfileFor(model)
ctl.Start(traffic.ArrivalRequest{Graph: g, Runway: "24", Parking: stand, Model: model,
    InjectApproach: true, Aircraft: &ac})

TakeoffProfileFor(model) and MotionProfileFor(model) remain as shortcuts for ProfileFor(model).Takeoff and .Motion.

Refining from SimVars

ProfileReader reads what the simulator reports about a spawned aircraft, through the application’s message loop like nav.WeatherReader:

pr := traffic.NewProfileReader(client, 8400, 8401)
pr.Request(objectID)
for msg := range client.Stream() {
    if v, ok := pr.Handle(msg); ok {
        ac := traffic.Refine(traffic.ProfileFor(v.ATCModel), v)
        _ = ac
    }
}

It reads WING SPAN, DESIGN SPEED VS0, DESIGN SPEED VS1, DESIGN TAKEOFF SPEED, DESIGN SPEED CLIMB, DESIGN SPEED VC, NUMBER OF ENGINES, ENGINE TYPE, MAX GROSS WEIGHT, TOTAL WEIGHT, FLAPS NUM HANDLE POSITIONS, STATIC CG TO GROUND, ATC MODEL, ATC TYPE and CATEGORY, and writes nothing. For object 0 (the user aircraft), the answer carries the user’s own object ID.

Refine then:

• gives a generic profile (Type "") the reported span and engine type, the final approach at 1.3 VS0 + 5 kt, rotation at DESIGN TAKEOFF SPEED, the climb at DESIGN SPEED CLIMB, and snaps its flaps to the handle detents;
• scales the speeds of any profile by weight, √(total / reference weight) within −12 % and +8 %, and the take-off acceleration inversely;
• takes a reported STATIC CG TO GROUND.

Known types keep their table airframe, speeds and flaps. A live read in MSFS 2024 at LKPR shows why:

AI models report every variable, but the airframe and weights are those of a simplified flight model: the FSLTL A320’s total weight exceeds its maximum, so Refine ignores weights above MAX GROSS WEIGHT. ATC MODEL, engine count and type, and STATIC CG TO GROUND are reliable.

Telemetry

A Recorder logs every controlled movement to JSON lines, one per arrival or departure when it ends (#308). Pass it the events the application already reads from a controller:

rec := traffic.NewRecorder(logFile)
stop := ctl.Plan().Stop
for ev := range ctl.Events() {
    rec.Arrival(traffic.MovementInfo{Model: model, Stop: &stop}, ev)
}
for _, s := range rec.Summary() {
    fmt.Printf("%s: %d arrivals, touchdown %.0f m at %.0f fpm\n", s.Type, s.Arrivals, s.TouchdownM, s.TouchdownFpm)
}

Each Movement has the model and type, the phase it ended in and any error, and — where they apply — the touchdown distance and vertical speed, the speed leaving the runway, the stand stop error, the lift-off distance from the start of the roll, and the mean and maximum taxi speed. Summary() (or Summarize over lines read back) gives per-type counts and medians to compare with the profile and tune it.