Winter Instruments MacCready Speed Ring - 304CZ

Nowadays, the MacCready type ring is an indispensable aid in cross country flying. The ring is rotatable and is marked with speeds and a white triangle. The chief use of MacCready ring is to achieve the highest possible cruising speed (average cross country flying speed) on thermal cross country flights. This involves setting the white arrow to the anticipated rate of climb for the next upcurrent. Optimum flight performance is assured when the airspeed indicated by the airspeed indicator corresponds to the preselected flying speed to which the MacCready ring has been set. The MacCready ring allows gliding distance and final approach to be optimized.