5 ms·if (altitude < 0) { return ERR_INVALID_ALTITUDE; }by mirekrusin 10y agoif (altitude < 0) { return ERR_INVALID_ALTITUDE; }dingaling 10y agoAircraft departing my local airfield commence at -4 metres according to GPS as it is actually below sea level.manarth 10y agoAnd the intended landing site is at an altitude of -250m referenced to the Martian datum.