Innovative Repair of Classic Hornet Centreline Pylons Based On Optimal Shape Reworking

摘要

The SUU-62 centreline pylon of an F/A-18 classic hornet aircraft is a load bearing component essential to the centreline store carrying capability of the aircraft. It has a known history of fatigue cracking at one of the forward attachment regions, which towards the end of 2014 led to the fleet-wide suspension of the centreline pylon usage in Australia. At that time new spares were not available within the timeframe needed to recover the highly desirable centreline carrying capability. Hence, an innovative solution was developed to repair the existing centreline pylons. This paper presents the key innovations and approaches that were integrated to enable the repair. These included an optimal designed rework shape that minimised the peak stress based on a biologically inspired algorithm interfaced with iterative FEA, a high precision surface inspection based on the cellulose acetate replica method, and a safe life estimation of the repaired assets based on a Weibull analysis. The presented repair solution was implemented, with a total of twenty-three SUU-62 centreline pylons being repaired and returned to Royal Australian Air Force service.