19 November 2004
19 November 2004
The National Institute for Aviation Research (NIAR) are investigating the polymer structure of the Beechcraft Starship in order to understand the degradation process of composite materials.
The Starship is 1 of only 53 that were ever produced during the late 1980s, and built largely put of non-metallic composites. The (NIAR) Aging Aircraft and Composites lab are evaluating one of such crafts that was in production until December 1994, just two years after it entered commercial service.
The production of the Starship used what was considered at the time to be advanced materials which, coupled with insufficient material knowledge and certified with conservative regulations, largely contributed to the rapid degradation of Starship's performance and economic viability.
The current program is being conducted on behalf of the NIAR's FAA Center of Excellence for Composites and Advanced Materials with NIAR Executive Director John Tomblin and Lamia Salah, Manager of the Fatigue and Fracture lab, the project's principal investigators.
It is hoped that data generated from this program will provide the industry with a better understanding of the aging phenomenon on the composite aircraft structure. Upon completion, the results will be used by the Federal Aviation Administration to assess the efficacy of the current emerging non-destructive investigation (NDI) methods to detect flaws.
Some of the issues the program will investigate include the changes in mechanical properties using coupon and element level testing, the degradation in physical properties and resin chemistry, the effectiveness of repairs, the material degradation due to heat, humidity and ultraviolet (UV) radiation and the bearing conditions and or failures around holes and fasteners.
The program is divided into two phases - each approximately 15 months in duration. The first phase will address NDI and materials and element level aging phenomenon of the structural components of the aircraft. The second phase of the program will address a full-scale test to assess the aircraft residual fatigue life the wing would be able to sustain after being in service for years.
""With the large number of aircraft flying with composite components, it is imperative that as an industry we understand the effects of age, both calendar and flight hour related, on composites prior to a structural failure,"" Melinda Laubach, Aging Aircraft manager said.