inline double getVerticalSpeed() const { return vs; };
inline double altitudeAGL() const { return props->getFloatValue("position/altitude-agl-ft");};
inline double airspeed() const { return props->getFloatValue("velocities/airspeed-kt");};
inline double getVerticalSpeed() const { return vs; };
inline double altitudeAGL() const { return props->getFloatValue("position/altitude-agl-ft");};
inline double airspeed() const { return props->getFloatValue("velocities/airspeed-kt");};