58. Application of Optimum Design Principles to Structural Weight Estimation

Paper

Abstract

In discussing any aspect of aircraft weight estimation, it is interesting to view the weight problem in relationship to the whole of airplane design. An illustration, appearing in some aeronautical textbooks, depicts a profile view of an aircraft in flight. Four vectors representing the forces acting upon the machine appear as; the Thrust (acting forward), the Drag (acting aft), the Lift (acting upward) and the Weight (acting downward).
From the values of these four forces and from their interdependencies, it is possible to describe the performance of the airplane. Obviously, reliable performance calculations depend upon an adequate knowledge of each force system.
Since we are concerned here with the Weight vector, it is interesting to compare the scope of our knowledge of Weight to that of Thrust, Drag and Lift.