Autonomous flight is performed in an open loop mode over a first range of altitudes, wherein a plurality altitude-related data from a plurality of altitude-related sensors is ignored while performing the autonomous flight in the open loop mode. The autonomous flight is performed in a closed loop mode over a second range of altitudes, wherein: the plurality of altitude-related data from the plurality of altitude-related sensors is used while performing the autonomous flight in the closed loop mode, and the first range of altitudes is a non-overlapping, lower range of altitudes compared to the second range of altitudes.