The Benchmark Active Controls Technology (BACT) model is a part of the Benchmark Models Program (BMP). The BMP is a NASA Langley Research Center program that includes a series of models which were used to study different aeroelastic phenomena and to validate computational fluid dynamics codes. The primary objective of BACT testing was to obtain steady and unsteady loads, accelerations, and aerodynamic pressures due to control surface activity in order to calibrate unsteady CFD codes and active control design tools. Three wind-tunnel tests in the Transonic Dynamics Tunnel (TDT) have been completed. The first and parts of the s cond and third tests focused on collecting open-loop data to define the model's aeroservoelastic haracteristics, including the flutter boundary across the Mach range. It is this data that is being presented in this paper. An extensive database of over 3000 data sets was obtained. This database includes steady and unsteady control surface effectiveness data, including pressure distributions, control surface hinge moments, and overall model loads due to deflections of a trailing edge control surface and upper and lower surface spoilers. SYMBOLS α angle of attack, alpha b model span (32 in.) c model reference chord (16 in.) CL lift coefficient = lift/qS CM pitching moment coefficient = pitching moment/qSc CP pressure coefficient = (P P ∞)/q C l rolling moment coefficient = rolling moment/qSb δ deflection of control surface M Mach number P pressure P∞ free stream pressure q dynamic pressure (1/2 ρ V) ρ density S reference area = bc V velocity x/c non-dimensional chord location NOMENCLATURE CS channel statistics data and tables dwell oscillation at a fixed frequency LinSS linear sine sweep LS lower spoiler MILEA model inboard leading edge accelerometer MITEA model inboard trailing edge accelerometer MOLEA model outboard leading edge accelerometer MOTEA model outboard trailing edge accelerometer MP magnitude and phase data and tables polar variation of a single parameter such as α, δTE, δUS, δLS PPN periodic pseudo-noise excitation TE trailing edge control surface TF transfer functions TH time history data US upper spoiler US+LS motion of upper and lower spoilers are in same direction US-LS motion of spoilers are in opposing directions INTRODUCTION Some of the interesting aeroelastic phenomena existing in today’s aircraft include the following: the classical transonic flutter “bucket”, wing/store limited amplitude flutter, shock induced instabilities, and dynamic vortex-structure interactions. Transonic aeroelastic phenomena are often very difficult to understand and analyze. With the rapid increase in computation speeds, new computational fluid dynamic (CFD) codes have matured sufficiently to Aeroelasticity Branch, Aerospace Engineer, Member AIAA Aeroelasticity Branch, Senior Aerospace Engineer, Associate Member AIAA Aeroelasticity Branch, Aerospace Engineer, Senior Member AIAA Subsonic Transportation Office, Aerospace Engineer, Senior Member AIAA Copyright © 1997 by the American Institute of Aeronautics and Aeronautics, Inc. No copyright is asserted in the United States under Title 17, U.S. Code. The U.S. Government has a royalty-free license to exercise all rights under the copy right claimed herein for government purposes. All other rights are reserved by the copyright owner.