Gust loads analysis on a civil transport airliner

Abstract

In the report, a comparison of gust loads analysis using the classical quasi-static Pratt gust approach, a fully dynamic approach and a Pratt-revised gust formula is undertaken. The evaluation has been performed for a one-degree-of-freedom rigid wing (to reflect and verify Pratt's assumptions in his classical gust definition) as well as for a fully elastic transport air-craft, the so-called DLR D150 configuration. In addition, a comparison has been carried out between the certification specifications CS-23 and CS-25 proposed by the European Aviation Safety Agency (EASA) to calculate gust loads on the aircraft structure. The CS-23 requires only the Pratt's quasi-static method while CS-25 requires the dynamic method for a range of gusts, flight and mass cases. For the analyses, the quasi-static and dynamic methods were implemented in MSC.Nastran, observing the flight envelopes required by the certification specifications.