QString Intersection::toString() const
{
    return QString("INT %1, %2, %3, %4 ").
        arg(m_id).arg(m_name).arg(latLonString()).arg(m_country_code);
}
QString Vor::toString() const
{
    return QString("VOR %1, %2, %3, %4, %5nm, %6ft, %7, hasDME:%8").
            arg(m_id).arg(m_name).arg(latLonString()).
            arg(m_freq / 1000.0).arg(m_range_nm).arg(m_elevation_ft).arg(m_country_code).arg(m_has_dme);
}