Cost Implications

Aircraft design strategy is constantly changing. Initially driven by the classical sub­jects of aerodynamics, structures, and propulsion, the industry is now customer – driven and design strategies consider the problems for manufacture and assembly that lead the way in reducing manufacturing costs. Chapter 16 addressed cost con­siderations in detail. In summary, an aircraft designer must be cost-conscious now and even more so in future projects.

It is therefore important that a basic exercise on cost estimation (i. e., second- semester classwork) be included in the curriculum. A word of caution: Academic pursuit on cost analysis to find newer tools is still not amenable to industrial use – manufacturers must rely on their own costing methodologies, which are not likely to appear in the public domain. How industry determines cost is sensitive information used to stay ahead in free-market competition.

I emphasize here that there is a significant difference between civil and military programs in predicting costs related to aircraft unit-price costing. The civil aircraft design has an international market with cash flowing back from revenues earned from fare-paying customers (i. e., passengers and freight) – a regenerative process that returns funds for growth and sustainability to enhance the national economy. Conversely, military aircraft design originates from a single customer demand for national defense and cannot depend on export potential – it does not have cash flowing back and it strains the national economy out of necessity. Civil aircraft designs share common support equipment and facilities, which appear as indirect operational costs (IOCs) and do not significantly load aircraft pricing. The driv­ing cost parameter for civil aircraft design is the DOC, omitting the IOC compo­nent. Therefore, using a generic term of life cycle cost (LCC) = (DOC + IOC) in civil applications, it may be appropriate in context but would prove to be off the track for aircraft design engineers. Military design and operations incorporating discreet advances in technology necessarily have exclusive special support systems, equipment, and facilities. The vehicles must be maintained for operation-readiness around the clock. Part of the supply costs and support costs for aircraft maintenance must be borne by manufacturers that know best and are in a position to keep con­fidential the high-tech defense equipment. The role of a manufacturer is defined in the contractual agreement to support its product “from cradle to grave” – that is, the entire life cycle of the aircraft. Here, LCC is meaningful for aircraft designers in minimizing costs for the support system integral to the specific aircraft design. Com­mercial transports would have nearly five times more operating hours than military vehicles in peacetime (i. e., hope for the life of the aircraft). Military aircraft have relatively high operating costs even when they sit idle on the ground. Academic lit­erature has not been able to address clearly the LCC issues in order to arrive at an applicable standardized costing methodology.

Aircraft design and manufacture are not driven by cost estimators and accoun­tants; they are still driven by engineers. Unlike classical engineering sciences, cost­ing is not based on natural laws; it is derived to some extent from manmade policies, which are rather volatile, being influenced by both national and international ori­gins. The academic pursuit to arrest costing in knowledge-based algorithms may not prove readily amenable to industrial applications. However, the industry could benefit from the academic research to improve in-house tools based on actual data. I am pleased to present in this book a relevant, basic cost-modeling methodology [11] from an engineer’s perspective reflecting the industrial perspective so engineers may be aware of the labor content to minimize cost without sacrificing design integrity. The sooner that engineers include costing as an integral part of design, the better will be the competitive edge.