Correlation of Aerodynamic Stability and Control Derivatives Obtained from Flight Tests and Wind Tunnel Tests on the XC-142A Airplane.
Report Number: AFFDL TR 68-167
Author(s): Black, Ernest L., Booth, George C.
Corporate Author(s): Ltv Aerospace Corp Dallas Tex Ltv Vought Aeronautics Div
Laboratory: Air Force Flight Dynamics Laboratory
Date of Publication: 1969-04
Pages: 198
Contract: AF 33(615)-2897
DoD Project: 8219
DoD Task: 821907
Identifier: AD0854018
Abstract:
A wind tunnel-flight data correlation program using the XC-142A airplane was undertaken to assess the degree of correlation attainable and to establish the sreas where present wind tunnel testing and correction techniques appear to be inadequate. Wind tunnel data obtained from tests of three models of the XC-142A airplane in four different size test sections could not be satisfactorily correlated because of differences in model configuration and test conditions. Three special tests were performed using the same model but in different size test sections of the same tunnel. The results of these tests indicated that with proper equipment and techniques, valid V/STOL wind tunnel data can be acquired. The flight data were obtained from the Contractor's Category I test program. The objective of this flight test program was primarily to perform a qualitative evaluation of the airplane rather than to obtain the quantitative data desired for aerodynamic analysis purposes. The flight data were not acquired in a manner that would provide suitable quality to allow a high degree of confidence in inverse solutions for aerodynamic derivatives. It is recommended that future programs include a critical review of the instrumentation system and flight maneuvers in order to obtain the best possible data for determining the low speed flight aerodynamic characteristics.
Provenance: Lockheed Martin Missiles & Fire Control
Author(s): Black, Ernest L., Booth, George C.
Corporate Author(s): Ltv Aerospace Corp Dallas Tex Ltv Vought Aeronautics Div
Laboratory: Air Force Flight Dynamics Laboratory
Date of Publication: 1969-04
Pages: 198
Contract: AF 33(615)-2897
DoD Project: 8219
DoD Task: 821907
Identifier: AD0854018
Abstract:
A wind tunnel-flight data correlation program using the XC-142A airplane was undertaken to assess the degree of correlation attainable and to establish the sreas where present wind tunnel testing and correction techniques appear to be inadequate. Wind tunnel data obtained from tests of three models of the XC-142A airplane in four different size test sections could not be satisfactorily correlated because of differences in model configuration and test conditions. Three special tests were performed using the same model but in different size test sections of the same tunnel. The results of these tests indicated that with proper equipment and techniques, valid V/STOL wind tunnel data can be acquired. The flight data were obtained from the Contractor's Category I test program. The objective of this flight test program was primarily to perform a qualitative evaluation of the airplane rather than to obtain the quantitative data desired for aerodynamic analysis purposes. The flight data were not acquired in a manner that would provide suitable quality to allow a high degree of confidence in inverse solutions for aerodynamic derivatives. It is recommended that future programs include a critical review of the instrumentation system and flight maneuvers in order to obtain the best possible data for determining the low speed flight aerodynamic characteristics.
Provenance: Lockheed Martin Missiles & Fire Control