Foreign objects debris and the future of aerospace composites

Airports, maintenance zones and even wind turbine sites face constant challenges in mitigating FOD. On busy airfields, debris is nearly inevitable due to the sheer volume of operations and the influence of environmental factors. Maintenance teams work tirelessly to manage this risk, yet the economic implications remain severe. Increased inspection frequencies, unscheduled repairs and the potential for unexpected downtime contribute to significant financial burdens on airlines and energy operators alike.

The vulnerability of aerospace composites

Modern aerospace structures increasingly rely on composite materials, particularly carbon fibre reinforced polymers, for their exceptional strength-to-weight ratios. However, the same characteristics that make composites ideal for reducing aircraft weight also render them susceptible to low-velocity impacts. Unlike metals, which can absorb and redistribute impact energy due to their ductility, composites can suffer internal damage that is not immediately apparent on the surface.

This BVID may manifest as microcracks, delamination or fibre breakage, all of which degrade the material’s performance over time. In routine inspections, BVID often escapes detection, allowing damage to accumulate and potentially leading to critical structural failures. Case studies from the industry reveal that even seemingly minor FOD incidents can reduce the fracture toughness of composite panels, compromise load-bearing capacities and necessitate expensive, unplanned repairs. For instance, maintenance records have documented cases where aircraft wings, appearing intact on the exterior, harboured extensive sub-surface damage that only advanced diagnostic tools could reveal.

Innovative solutions: intelligent composite materials

The growing vulnerability of composites to FOD-induced damage has spurred the development of intelligent composite materials. Rather than relying solely on periodic, schedule-based inspections, intelligent composites offer real-time SHM.