731. Airframe Cost Element Prediction and Application to Cost Control

Paper

Abstract

The cost of a new air vehicle is significantly affected by the airframe unit weight, by the number of dissimilar parts and total pieces, and by the type of materials and manufacturing processes used to fabricate the airframe. These airframe cost elements are being estimated at the preliminary design stage by Convair’s Engineering Mass Properties group, using semi-empirical methods similar to those used for estimating weights. The methods are backed up by a growing historical airframe data bank on General Dynamics aircraft. The data in this bank is compiled along MIL-STD-254(ASG) ‘AN 9102 Detail Weight Statement’ lines.
The cost element prediction methods at Convair have progressed to the point where plans are now being made for budgeting, tracking, and controlling airframe unit weight and parts count data during the original production design phase, as part of the weight reporting and control function. When this plan is implemented, it will give management a diagnostic tool to monitor and perhaps control program cost trends. This paper discusses the background, procedures, problems, and prospects of cost element predictions, and its role in aircraft cost control. It also discusses the need for inter-company airframe cost element data exchange, and calls for government specifications governing the documentation and reporting of these elements.