SAO.IDE.105 Flight and navigational instruments

(a)  Sailplanes shall be equipped with a means of measuring and displaying all of the following:

(1)  time in hours and minutes;

(2)  pressure altitude;

(3)  indicated airspeed;

(4)  in the case of powered sailplanes, magnetic heading.

(b)  In addition to (a), when operating in conditions where the sailplane cannot be maintained on a desired flight path without reference to one or more additional instruments, when conducting cloud flying or when operating at night, sailplanes shall be equipped with means of measuring and displaying all of the following:

(1)  vertical speed;

(2)  attitude or turn and slip;

(3)  magnetic heading.