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Stability and Control Estimation Flight Test Results for the SR-71 Aircraft With Externally Mounted ExperimentsA maximum-likelihood output-error parameter estimation technique is used to obtain stability and control derivatives for the NASA Dryden Flight Research Center SR-71A airplane and for configurations that include experiments externally mounted to the top of the fuselage. This research is being done as part of the envelope clearance for the new experiment configurations. Flight data are obtained at speeds ranging from Mach 0.4 to Mach 3.0, with an extensive amount of test points at approximately Mach 1.0. Pilot-input pitch and yaw-roll doublets are used to obtain the data. This report defines the parameter estimation technique used, presents stability and control derivative results, and compares the derivatives for the three configurations tested. The experimental configurations studied generally show acceptable stability, control, trim, and handling qualities throughout the Mach regimes tested. The reduction of directional stability for the experimental configurations is the most significant aerodynamic effect measured and identified as a design constraint for future experimental configurations. This report also shows the significant effects of aircraft flexibility on the stability and control derivatives.
Document ID
Document Type
Technical Publication (TP)
Moes, Timothy R. (NASA Dryden Flight Research Center Edwards, CA United States)
Iliff, Kenneth (NASA Dryden Flight Research Center Edwards, CA United States)
Date Acquired
September 7, 2013
Publication Date
June 1, 2002
Subject Category
Aircraft Stability and Control
Report/Patent Number
NAS 1.60:210718
Funding Number(s)
PROJECT: RTOP 710-35-14-E8-OM
Distribution Limits
Work of the US Gov. Public Use Permitted.

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