Since the introduction of the all-composite Boeing 787 aircraft into commercial service in 2011 and the Airbus A350 in 2015, there have been numerous examples of these aircraft sustaining damage in service. These aircraft are constructed using a significant amount of advanced composite materials, such as carbon fibre-reinforced polymers. These materials, while offering benefits of reduced weight and improved fuel efficiency, are far more costly than traditional aluminium and require specialised handling and repair techniques. Repairing composite materials is more complex than repairing traditional metal structures. Composite repairs often involve intricate processes such as layering, curing, and bonding, which require specialised equipment and facilities. These processes are time-consuming and labour-intensive, contributing to higher repair costs. Often, repairs on advanced composite structures like those on the Boeing 787 or Airbus A350 are normally exclusively repaired by the OEMs as they alone hold the authority and are ultimately responsible for the design and certification of these repairs. This involvement can, of course, add to the cost due to the premium charged by OEMs for their repair design, expertise, and oversight.

A recent example highlighted the challenges faced by composite-constructed aircraft. A composite aircraft suffered an in-flight lightning strike, resulting in significant burning of the fuselage structure and wingtip, requiring an extensive manufacturer's repair. On a traditional aluminium fuselage aircraft, this type of event typically results in superficial damage, such as burn marks, pitting, or small holes on the aircraft's fasteners or skin. These are usually found at the entry and exit points of the lightning strike, where the electrical current enters and leaves the aircraft. Fuselage repairs are normally relatively minor, with burnt fasteners being replaced or minor fuselage skin repairs being completed. Therefore, lightning strike repairs and associated repair costs on a traditional fuselage aircraft would not be significant.

In contrast, the lightning strike event on the composite aircraft caused a significant amount of localised heating at the points where the electrical current touched the fuselage and wingtip skin surface. Composite materials can suffer from thermal damage, which includes resin decomposition, delamination, and fibre breakage. The high temperatures can cause the resin layers to burn or vaporise, leading to a loss of structural integrity. In this case, the breakdown of the resin between the plies resulted in large areas of delamination that required extensive manufacturer's repairs. The aircraft was out of service for almost five months resulting in repair and claim costs of more than USD7m.

Although this is an extreme example, as of the latest data available, only a relatively small percentage of the world fleet of commercial passenger aircraft are manufactured using composite materials. The most notable examples, as indicated above, include the Boeing 787 and the Airbus A350, both of which feature significant use of composite materials in their fuselage and wing construction. While exact percentages can vary depending on the source and the specific criteria used, it is estimated that aircraft with composite fuselage such as the Boeing 787 or Airbus A350 make up less than 7% of the total global commercial passenger aircraft fleet. The majority of the current fleet in operation still consists of aircraft with traditional aluminium fuselages, such as the Boeing 737, Airbus A320, and older models like the Boeing 777 and Airbus A330, which use composites primarily in specific components such as panels and fairings rather than the entire fuselage.

However, the adoption of composite materials is expected to grow as newer models like the Boeing 787 and Airbus A350 continue to be delivered and as future aircraft designs increasingly incorporate advanced materials to improve efficiency and performance. Looking ahead, as fleet modernisation to all composite constructed aircraft continues and older conventional aluminium-designed aircraft are retired, it is highly likely that maintenance repair costs and ultimately claims will continue to rise in value.