Accession Number : AD0850956

Title :   V/STOL Flight Test Instrumentation Requirements for Extraction of Aerodynamic Coefficients. Volume I.

Descriptive Note : Final rept. Dec 67-Sep 68,

Corporate Author : LTV AEROSPACE CORP DALLAS TX VOUGHT AERONAUTICS DIV

Personal Author(s) : Hill, Richard W. ; Clinkenbeard, Ivan L. ; Bolling, N. F.

Report Date : OCT 1968

Pagination or Media Count : 326

Abstract : The results of a synthesis of pertinent maneuvers with a mathematical model of the XC-142 V/STOL airplane have served to establish tolerances in the measurement of flight parameters which provide the time histories used in the derivation of aerodynamic coefficients. Extracting valid aerodynamic coefficients from flight test time histories requires highly accurate instruments or detailed a priori knowledge of instrumentation errors. Furthermore, the mathematical technique used should provide the capability of extracting many coefficients simultaneously and delineating the probable error of each coefficient. The method of multiple linear regression, a least squares algorithm, provides the requisite mathematical tool with adequate statistical credentials. A state-of-the-art survey and a vendor-product-line review have provided guidelines for a system that will meet the overall accuracy requirements established. Details of equipment installations, oriented toward minimizing environmental stresses (particularly vibrations), have been studied. Conclusions drawn from this program are that the assembly and application of a precision data acquisition system based on digital 'onboard' handling techniques, with the appropriate sensing instrumentation, is entirely feasible but that limited development of measurement techniques, hardware, and software are required. (Author)

Descriptors :   *INSTRUMENTATION), (*VERTICAL TAKEOFF AIRCRAFT, AERODYNAMIC CHARACTERISTICS), (*DATA PROCESSING, MATHEMATICAL MODELS, ACCURACY, ERRORS, LEAST SQUARES METHOD, VIBRATION, FEASIBILITY STUDIES, AIRSPEED INDICATORS.

Subject Categories : V/STOL
      Test Facilities, Equipment and Methods
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE