An Evaluation Technique for an F/A-18 Aircraft Loads Model Using F/A-18 Systems Research Aircraft Flight Data

Olney, Candida D. and Hillebrandt, Heather and Reichenbach, Eric Y. (2000) An Evaluation Technique for an F/A-18 Aircraft Loads Model Using F/A-18 Systems Research Aircraft Flight Data. Technical Report NASA/TM-2000-209028, Research Engineering, NASA Dryden Flight Research Center.

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Abstract

A limited evaluation of the F/A-18 baseline loads model was performed on the Systems Research Aircraft at NASA Dryden Flight Research Center (Edwards, California). Boeing developed the F/A 18 loads model using a linear aeroelastic analysis in conjunction with a flight simulator to determine loads at discrete locations on the aircraft. This experiment was designed so that analysis of doublets could be used to establish aircraft aerodynamic and loads response at 20 flight conditions. Instrumentation on the right outboard leading edge flap, left aileron, and left stabilator measured the hinge moment so that comparisons could be made between in-flight-measured hinge moments and loads model-predicted values at these locations. Comparisons showed that the difference between the loads model-predicted and in-flight-measured hinge moments was up to 130 percent of the flight limit load. A stepwise regression technique was used to determine new loads derivatives. These derivatives were placed in the loads model, which reduced the error to within 10 percent of the flight limit load. This paper discusses the flight test methodology, a process for determining loads coefficients, and the direct comparisons of predicted and measured hinge moments and loads coefficients.

EPrint Type:	NASA Technical Memorandum
Keywords:	Active aeroelastic wing, F/A-18, Flight test, Loads, Simulation
Subjects:	(01 - 09) Aeronautics: (05) Aircraft Design, Testing And Performance Aircraft/Project: F-18 AAW
ID Code:	81
Deposited On:	12 July 2004
Additional Information:	29 pages. Prepared for the 31st SFTE Annual Symposium 2000, Torino, Italy, September 18–22, 2000. Candida D. Olney and Heather Hillebrandt, NASA Dryden Flight Research Center, Edwards, California, and Eric Y. Reichenbach, The Boeing Company, Phantom Works, St. Louis, Missouri.