1223. A Credible Cost Estimating Procedure for Composite Airframes

Paper

Abstract

Confidence in advanced technologies must be gained in the early stages of fighter aircraft design in order to cascade the benefits and realize the full advantage of these technologies. By starting now to build on the existing technology base, we can reduce the size and improve the performance of emerging fighter aircraft systems. For example, the judicial application of light weight advanced composite materials can reduce structural weight fractions. When this reduction is accomplished early in system design, it cascades into reduced propulsion system and fuel requirements further reducing the size of the aircraft required for a given mission. Obviously, this reduction in vehicle size will have far-reaching benefits in system acquisition and life-cycle costs and in increased survivability within a hostile environment. For these reasons, interest in composite structure remains high; however, expanded application of composite construction is inhibited by the lack of high-quality cost data.
Generation of high-quality cost data for a high-technology area such as advanced composites is not a straight forward task. Adequate historical data is simply non-existent. With the exception of a few secondary structural elements, no major component production hardware programs have been initiated. Material and labor cost projections must come from efforts either performed on test specimens or expended on test article development programs or from data from relatively limited production programs
General Dynamics has selected an innovative approach to the solution of this problem, one which capitalizes on available data and yet is sufficiently flexible to accept new data as it is generated. This approach, known as the detail part cost estimation approach, involves the:
o Unique identification of the detail parts comprising a composite airframe.
o Definition of a complete manufacturing plan for fabricating and assembling the airframe.
o Computation of the labor required in manufacturing the airframe by use of industrial engineering time standards.
o Summation of airframe costs and weights in a form suitable for future analyses.
The program discussed in this article has been structured to address airframe structure-related costs. The approach defined addresses those most basic costs which are under the direct control of the airframe manufacturer. This program will be available for industry use in March 1979.