public string TakeOff(AerialVehicle a)
{
if (Vehicles != null)
{
Vehicles.Remove(a);
return("This vehicle took off");
}
else
{
return("There are no vehicles to take off");
}
}
public string Land(AerialVehicle a)
{
if (Vehicles.Count < MaxVehicles)
{
Vehicles.Add(a);
a.FlyDown(a.CurrentAltitude);
a.IsFlying = false;
return(this + " has landed.");
}
else
{
return("The vehicle is not at 0 altitude yet.");
}
}