C. P. No. 715 MINISTRY OF AVIATION

I@? pzpz prcoents results of wind tunnel flutter tests wing a wing-G.lcron-tab model on which it was possible to represent any of the following 1P!b s~-StEm ; spring, geared, trim or servo. Prediction of the flutter-r;h?racteristics has ken made in the trim tab case using three sets of aero-dJTwic dwlvatives and fair agreement has been reached with the measured charccteristics. A comparison has also been made of the measured character-rstxs with those predicted by the latest flutter criteria and possible modifications to the basic flutter frequency assumption used in deriving the criteria are discussed. One modification suggested is such that the basic Xutter freqvelx;r is virtually depandent on the frequency in a single degree of freedom. The criterion form that results from such a single frequency opp?oximation is investigated.