A SLIDE RULE FOR THE COMPUTATION OF PRECISION TURNS IN AIR SURVEY NAVIGATION

Calculated precision turns can be valuable as an aid to visual navigation at all scales and under all conditions of air survey navigation. The turns can be performed either at a given rate of turn or at a given angle of bank, and a slide rule has been developed at the International Training Centre for Aerial Survey, Delft, on which the necessary calculations for either case can be performed quickly and easily. The accuracy of location aimed at is such that the threshold of the new run presents an angle-off of not more than 3° on the completion of the turn. Examples show that this can be achieved in normal practice. Resume Ľ auteur expose les principes ďune regie a calcul realisee par ľI.T.C. a Delft, et qui a pour but ľamelioration de la navigation des missions photographiques en ce qui concerne les tours au bout de chaque bande. Quelques exemples demontrent comment on arrive en pratique a la precision voulue.