CONCEPTUAL STUDY OF A HIGHLY SURVIVABLE COMPOSITE TRUSS TAILBOOM

Military activities in the past ten years have subjected the helicopter to increased exposure of air defense measures. Attrition analysis performed by the Army shows tailboom damage could be a significant contributor to helicopter combat loss. Attempts to reduce the vulnerability of small diameter conventional tailbooms have meant an excessive weight increase and/or large modification cost. To determine a methodology for the solution to the tailboom vulnerability problem, the design options available to the aircraft designer are monocoque, semi-monocoque, or truss. In order to determine if a composite truss was a viable concept for a ballistically tolerant tailboom, the Applied Technology Laboratory, Fort Eustis, Virginia, awarded a contract to Bell Helicopter Textron to design and build three composite truss tailboom specimens. This paper will present a review of this contracted program. Filament winding methods and procedures used in the fabrication of truss specimens as well as the ballistic testing will be discussed. Results and conclusions will also be included in this paper.