Even at the nose, many factors can affect the relationship between the local AOA and true wing AOA (fig. 9). The angle of airflow around the nose is not the same as at the wing. Also, the sensitivity to changes in AOA is greater, so a 1-deg change in true wing AOA causes a local flow change at the nose of 1.5 to 2 deg.
This confuses many people. In simple terms: A datum is a system which allows the location of latitudes and longitudes (and heights) to be identified onto the surface of the Earth-ie onto the surface of a âroundâ object.
Chart datum. A chart datum is the level of water that charted depths displayed on a nautical chart are measured from. A chart datum is generally a tidal datum; that is, a datum derived from some phase of the tide.[1] Common chart datums are lowest astronomical tide[1] and mean lower low water.