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.
Other nations' maps often use coordinates computed assuming the Earth is a completely different size and shape from what the Department of Defense uses, but we have to be ready to fight around the world. US forces now use a datum called World Geodetic System 1984, or WGS 84. The National Imagery and Mapping Agency (NGA) produces all of its new maps with this system. Unfortunately, we reprint many of our maps from products made by allied countries that use local datums.
1 Rule of non-override: No datum feature (datum feature simulator, datum) shall influence degrees of freedom already constrained by higher precedence datum features. 2  The âcan-may-mustâ rule: If a datum feature (datum feature simulator, datum) can constrain a degree of freedom, and it may, then it must.