Field-Survey-Based Evaluation of Realistic and Remote Wing Impact Energy Levels

Abstract

The field survey containing data on wing accidental impact damages registered on Russian commercial fleet was generated. The damages were classified by the wing elements and the sources of impact. To use metal fleet experience for damage tolerance analysis of composite structures, the original method to recover impact energy from the dent depth was applied, and metal impact dents were recalculated into energies. The statistical analysis of the energy database was performed. It was demonstrated that data distribution can be reliably described by log-normal law. For the two surveys (the current one and the second taken from U.S. Navy data), on a similar data sample using the Rouchon probabilistic approach, the energy threshold values for nondetectable and barely detectable damages were evaluated. It was shown that the basic relationships and distributions obtained on domestic data generally agree with similar results obtained on other types of aircraft having considerable differences in design and operating conditions. The consideration of high and unrealistic energy cases was performed. Under the assumption that a high-energy impact event may be missed or unreported by personnel, the conservative estimation of the probable energy level was made. The limitations for usage of evaluated energy levels in design and certification were discussed.