The full value of A.P. 3270 (Sight Reduction Tables for Air Navigation, Vol. I, Selected Stars, H.M. Stationery Office) does not yet seem to have been fully appreciated by surface navigators. As well as increasing the speed with which sights can be reduced, the tables offer all the advantages of a star globe or planisphere in planning a series of sights. The navigator can thus concentrate on the most suitable stars for cut, magnitude and azimuth. Since observations can be planned for a time at dusk when the horizon is still firm and the star just visible through the telescope (or, at dawn, when the star is still visible and the horizon firm), a more accurate sextant altitude can be obtained.