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A study was conducted to demonstrate the ability of a low order panel aerodynamic flow code to predict the aircraft-induced propeller plane flow field and the resulting steady state propeller blade loads for a single-rotation, wing-mounted tractor system. Comparisons between predicted and measured flow field surveys and resulting blade loads, including the first five harmonics, were made for the U.S. Navy P-3C land-based patrol turboprop aircraft. The study showed that low order flow codes accurately model the induced flow field.

Second generation, or toughened, epoxy resin systems are under consideration for use on a large composite primary structural part such as a wing. A method of evaluating the properties of these materials, while at the same time considering design, structural and manufacturing requirements has been developed. Processability requirements for toughened epoxy resin systems have been established. Cost efficient manufacturing methods, such as pultrusion, have been investigated and found to be a feasible production method for composite structure. The use of pultrusion as a fabrication method for partially staged parts to be co-cured at a later date is being evaluated.

This paper presents an overview of design considerations, design development, and maintenance practices required to certify a commercial transport aircraft and ensure continuing airworthiness in operation. Subjects discussed include philosophy and criteria of airworthiness with examples of their application; evolutionary nature of the design development; scope of development testing; and the process involving manufacturer, operator, and regulatory agency to ensure continuing airworthiness throughout the aircraft operational life. Also discussed are the recent revisions in airworthiness regulations, which, along with advances in technology, have resulted in changing trends in the approach to substantiating continuing airworthiness, particularly for structures.

A successful short-haul transport must satisfy customer and marketplace requirements and be attractive economically. This paper examines the marketplace in the late 1970 time period to determine the payload-range and other performance requirements for a wide-bodied twin-jet transport. Environmental and operating cost targets are established, and the size of the market is estimated. An “optimal” design is then described which essentially represents the best possible airplane using the technology available in the time period best suited to the customer and marketplace requirements. Design data are presented that show the sensitivities of the design to some of the primary configuration variables. Certain design compromises are considered that have to do with airframe commonality with the manufacturer's other transports.