(aviation) The approach course formed by the rear lobe of the signal pattern of a localizer antenna array (the portion of the localizer signal emitted from the rear face of the antenna array), oriented in the reciprocal direction to the primary approach course (i.e., the back course - if a usable back course exists at all - will be rotated 180° from the primary course). Not all localizers produce a usable back-course signal; newer equipment radiates very little signal into the rear and side lobes, not enough to allow for a back-course approach.

plural of refresher course

Not occurring in the normal course of things.

(architecture) A continuous row or layer of stones or brick set in a wall.

A study programme that is carried on by post, with tutors mailing learning materials and assignments to students, and students mailing back their work.

plural of belt course

Informal form of of course.

plural of course to steer

(navigation) The estimated course that a boat should steer in order to arrive at a waypoint, bearing in mind the effects that wind and tide will have on the vessel.

plural of string course