The cost of water ingression on honeycomb repair and utilization

In this study, the costs of honeycomb composite repairs from water ingression on the Boeing 767 were investigated, and three cost repair scenarios were considered. These scenarios represent the current commercial honeycomb repair methods, the implementation of a honeycomb/water maintenance program and the design and qualification of a new honeycomb core or composite panel architecture. These models differ from the practiced polices of almost all airlines today. This analysis makes an order of magnitude analysis on the best and worst case scenarios for repairing honeycomb core The current repair method was assumed not to correct any water ingression in the honeycomb panels until delamination occurred and took into account the cost of a new panel. Over an assumed life of 25 years, the costs for repairing composites in this way were $280,000 per plane. In the second scenario a thermographic monitoring program was put in place to locate ingressed water and it was assumed that the part could be repaired before replacement was necessary. This scenario put the repair cost of honeycomb composite structures at $20,000 per plane. Lastly the cost of qualifying a new honeycomb core is discussed. Costs sensitivity analyses are also presented with regards to fuel price, labor rates, interest rates, life cycle time and water accumulation rates.