1. An apparatus for monitoring the alignment of an aircraft wing relative to a substantially rigid fuselage of said aircraft comprising: at least first, second, and third target spots fixed in relation to said wing and defining a target plane, said target spots having median points thereof which form verticies of a triangle, said median point of said first spot defining an orgin of a co-ordinate system on said target plane; imaging means rigidly mounted on said fuselage with a field of view including said target spots, said imaging means including an imaging lens and a two dimmensional image plane for obtaing first, second, and third spot images thereon corresponding to said target spots projected on said image plane through said imaging lens; first means coupled to said imaging means for determining coordinates of median points of said image spots on said image plane; and second means, responsive to signals representative of (i) said coordinates of said median points of said image spots, (ii) distances between said median points of each of said target spots, (iii) the distance between said lens and said image plane, and (iv) the distance between said lens and each of said target spots, for determining the orientation of said target plane relative to said image plane thereby providing an indication of the orientation of said wing relative to said fuselage.