and Its Use in Measuring Aileron and Rudder Effectiveness of a Light Airplane

Scientific and Technical Information Office 1980 SUMMARY A hydrogen-peroxide-fueled rocket system was intalled on a light, four-place general aviation airplane to provide known moments about the roll and yaw body axes for use in measuring aerodynamic control power for all flight conditions. The system produced thrust up to about 490 N (110 lbf) (producing either a yawing or rolling moment of 2500 N-m (1840 ft-lbf)) with pilot-controlled firing time totaling about 60 sec per fuel load. A total of 15 flight opera-tions with approximately 20 min of accumulated rocket firing time was accom-plished with no major system malfunction. This experience demonstrated the operational readiness of the system for use in spin tests. and CQ) were measured by (c.6 r a Rudder and aileron effectiveness using the rocket-produced moments to balance the aerodynamic control moments for airspeeds somewhat above the stall to near cruise speed (approximately 65 to 100 knots). These results agreed very well with results obtained from dynamic flight maneuvers using the maximum likelihood method of stability derivative extraction. Canparison of the measured derivatives with those obtained by readily available estimation techniques indicated that the esti-mates for both derivatives differed appreciably from those measured