private NextPlanNodeParameter GetNextPara(IPlanNode node)
{
// Compute verical mode.
double optCrzAlt = fuelData.OptCruiseAlt(node.GrossWt);
double heading = HeadingCalculation.Heading(node.PrevWaypoint, node);
double atcAllowedAlt = altProvider.ClosestAlt(node, heading, optCrzAlt);
double targetAlt = Min(atcAllowedAlt, maxAlt);
double altDiff = node.Alt - targetAlt;
VerticalMode mode = GetMode(altDiff);
// Time to next waypoint.
double disToNextWpt = node.Distance(node.PrevWaypoint);
double timeToNextWpt = disToNextWpt / node.Gs * 60.0;
// Time to target altitude.
// ClimbRate is positve for climbs and negative for descents.
double climbGrad = ClimbGradient(node.GrossWt, mode);
double climbRate = climbGrad * node.Ktas / 60.0 * NmFtRatio;
bool isCruising = Abs(altDiff) < AltDiffCriteria;
double timeToTargetAlt = isCruising ?
double.PositiveInfinity :
altDiff / climbRate;
double[] times = { timeToNextWpt, DeltaT, timeToTargetAlt };
int minIndex = times.MinIndex();
double stepTime = times[minIndex];
Type nodeType = minIndex == 0 ?
typeof(RouteNode) :
typeof(IntermediateNode);
return(new NextPlanNodeParameter(mode, nodeType, stepTime, climbRate));
}
public static double EstimatedCrzAlt(this FuelDataItem item,
double distance, double landingWt)
{
var grossWt = item.EstimatedAvgWt(distance, landingWt);
var lim = item.DistanceLimitedAltitude(distance, grossWt);
var opt = item.OptCruiseAlt(grossWt);
return(Math.Min(lim, opt));
}
private double Kias(double grossWt, double alt)
{
if (alt <= 10000.0)
{
return(250.0);
}
var cruiseKias = fuelData.CruiseKias(grossWt);
var optAlt = fuelData.OptCruiseAlt(grossWt);
var optCruiseKtas = Ktas(cruiseKias, optAlt);
var kias = fuelData.ClimbKias;
var ktas = Ktas(kias, alt);
return(ktas > optCruiseKtas?KtasToKcas(optCruiseKtas, alt) : kias);
}
public static double EstimatedAvgWt(this FuelDataItem item,
double distance, double landingWt)
{
double grossWt = landingWt;
const int iteration = 2;
for (int i = 0; i < iteration; i++)
{
var alt = item.OptCruiseAlt(grossWt);
var ktas = Ktas(item.CruiseKias(grossWt), alt);
var time = distance / ktas * 60.0;
var ff = item.CruiseFuelFlow(grossWt);
grossWt = landingWt + ff * time / 2.0;
}
return(grossWt);
}
