NASA Contractor Report CR-73258 (download full report here or here)
By L. Pazmany, H. Prentice, C. Waterman and F. Tietge
The expansion and competitive position of general aviation in the field of transportation depends upon improving the safety and utility of light aircraft while reducing their cost. Toward this end, the Mission Analysis Division of NASA is investigating various areas associated with the design of light aircraft and has sponsored this study on structural materials and concepts.
The primary objectives of the study were:
(1) To make a comparative evaluation of a wide variety of materials and structural concepts, presently and potentially available for application to light aircraft, by investigating the effect of design, manufacturing, operational, and material requirements on the cost of this class of aircraft.
(2) To apply the more promising materials and structural concepts to the conceptual design of light aircraft.
(3) To identify key problem areas where additional research may Increase the potential of promising materials or concepts. In pursuing these objectives, the contractor was to consider two levels of technology and two types of light aircraft, fixed and rotary wing. “he levels of technology were classified as “near term,” 5 years hence, and “far term,” 15 years hence. The conceptual designs were to meet the contract guidelines listed in Appendix M.
The study was performed in two phases. Phase I was concerned with researching, correlating, and evaluating available information on (a) operational characteristics; (b) material properties; (c) structural concepts and capabilities; (d) manufacturing and cost considerations; as they apply to light four-place airplanes and helicopters. The intent of Phase II was to select the more promising structural materials and concepts and apply them to the two. conceptual designs for the two levels of technology. However, upon completion of Phase I, the results indicated (a) that the economic gains associated with improved light aircraft structural design would be more significant for “far term” aircraft; (b) that light fixed wing and light helicopters structures are similar; (c) the need for a more definitive analysis of the fabrication cost of the selected materials and concepts.
Thus, it was decided (with the agreement of NASA) to eliminate from consideration in Phase II the “near term” airplane and helicopter, and the “far term” helicopter. Phase II concentrated on establishing detailed structural design, cost, and fabrication analyses for those materials and concepts that showed the most promise of reducing labor hours and facilitating mass production as applied to the “far term” light airplane conceptual design.
A major aim of the study was to identify key problem areas where additional research would increase the potential of the more promising materials and concepts and lead to safer and more economical light aircraft.