Dynamic characteristics of active twist rotor (ATR) blades areinvestigated analytically and experimentally in this paper. The ATR system isintended for vibration and potentially for noise reductions in helicopters throughindividual blade control. An aeroelastic model is developed to identifyfrequency response characteristics of the ATR blade with integral, generallyanisotropic, strain actuators embedded in its composite construction. An ATRprototype blade was designed and manufactured to experimentally study thevibration reduction capabilities of such systems. Several bench and hovertests were conducted and those results are presented and discussed here.Selected results on sensitivity of the ATR system to collective setting (i.e. blade loading), blade rpm (i.e. centrifugal force and blade stationvelocity), and media density (i.e. altitude) are presented. They indicatedthat the twist actuation authority of the ATR blade is independent of thecollective setting up to approximately 10P, and dependent on rotational speedand altitude near the torsional resonance frequency due to its dependency onthe aerodynamic damping. The proposed model captures very well the physics andsensitivities to selected test parameters of the ATR system. The numericalresult of the blade torsional loads show an average error of 20% in magnitudeand virtually no difference in phase for the blade frequency response.Overall, the active blade model is in very good agreement with the experimentsand can be used to analyze and design future active helicopter blade systems.