private string Land(AerialVehicle a)
{
if (vehicles.Count < maxVehicles)
{
a.CurrentAltitude = 0;
a.IsFlying = false;
return($"{a} has landed.");
}
else
{
return($"{a} cannot land because the airport is full!");
}
}
private string TakeOff(AerialVehicle a)
{
a.TakeOff();
return($"{a} has taken off.");
}
