A frequently cited statistic for Boeing’s newest clean-sheet aircraft, the 787 Dreamliner, is that it is composed of 50% composites. While the carbon fiber reinforced materials (CFRP) do account for half of the widebody jet’s weight, they actually compose far more than that in terms of its structural volume. Those advanced composite materials are much lighter than their aluminum and other metal counterparts, so far more of the airframe structures and components can be made from composite than from metal, keeping the huge plane very light overall.

It is frequently said that the Dreamliner is constructed of 50% composite materials, yet this is actually a slightly inaccurate description of the plane. Science Direct says the plane is composed of 80% composite, 20% aluminum, 15% titanium, 10% steel, and the last 5% is a mix of other materials. Let’s dive into the engineering behind why so much of this plane was made from these innovative new materials and how that has changed the world of widebody, long-haul commercial flying.

Reinventing the Jetliner

One of the primary achievements of the 787 Dreamliner design is its monocoque fuselage, which has internally integrated stiffening structural components that dramatically reduce the number of fasteners required to assemble the airframe. The massive aerostructure is built using robotic equipment that pours carbon fiber epoxy resin, which is then cured in large autoclaves. When the molds roll out of the high-pressure steam chambers (autoclaves), they are ready to become the central pillar of a cutting-edge airliner.

Massive robotic arms « weave » the fuselage by layering carbon fiber tape onto a rotating cylindrical mold. The carbon fiber is « pre-impregnated » with epoxy resin (prepreg), which must be kept refrigerated like fresh food to maintain its properties before curing. The high-pressure ovens used to cure the Dreamliner fuselages are the world’s largest industrial autoclaves, with internal diameters of up to 30 feet and lengths of 75 feet, setting a Guinness World Record.

Advanced composite materials are also used to construct aircraft wings, which employ an innovative shape to achieve the same aerodynamic effect as winglets. The composite not only helps engineers achieve the aspect ratio and wingtip vortices disrupting shapes that improve fuel efficiency, but also makes the wings extremely flexible, which simultaneously makes them more durable, safer, and more aerodynamically efficient.

Made In America, Crafted In Japan

The Japanese material manufacturer, Toray, commercialized the T800S carbon fiber, which offered a quantum leap in the strength-to-weight ratio and modulus, enabling the radical weight reductions seen in the 787. Toray earned its first Boeing certification for airplane materials in 1978. Its materials were first used in secondary structures, like the tail and floor beams of the 777, before being used for the 787’s frame and body.

Toray began carbon fiber research in 1961 and started commercial production in 1971. Toray developed a proprietary toughened epoxy resin that acts as the matrix for the fibers. While many global chemical companies abandoned carbon fiber due to high costs, Toray persisted by refining the technology through high-end consumer goods like fishing rods, golf shafts, and tennis rackets.

Toray’s primary contribution is a material called Torayca prepreg. This is not just raw carbon fiber, but a high-performance system. Unlike earlier resins that were brittle, this formula allowed the composite to absorb significant energy without cracking, a critical requirement for the primary airframe. Toray is now the exclusive supplier of carbon fiber composite materials for the 787’s primary structural elements, including the fuselage and wings.

Simpler & Stronger

The shift from aluminum to composite fuselage construction was the key innovation behind the Dreamliner. This process allowed Boeing to move away from using thousands of aluminum sheets to a one-piece barrel fuselage. This eliminated approximately 40,000 to 50,000 fasteners per aircraft, drastically reducing weight and potential points of failure. Its 20% weight reduction (compared to legacy jets) contributes to a 20-25% improvement in fuel efficiency compared to the aircraft it replaced.

Composites handle tension exceptionally well, making them ideal for the fuselage and wings, while aluminum is retained for areas where its compression handling is superior. Composite does not corrode, while aluminum is also extremely resistant to corrosion; composite is also far less susceptible to fatigue. So not only does the CFRP reduce labor, potential weaknesses, and overall weight, but it also significantly reduces wear and tear, saving on maintenance over the plane’s lifetime.

All of that sounds great for the airline, but it’s not just Boeing and the operators that benefit from these enhancements. The exceptionally strong single-piece composite fuselage allows Boeing to pressurize the cabin to a higher level, which in turn decreases the simulated altitude inside from 8,000 feet to 6,000 feet. That has a significant impact on passenger fatigue and the aftereffects of jet lag.

The Right Material For The Job

Because CFRP is nearly half the density of aluminum and one-fifth the density of steel, it occupies a much larger physical portion (volume) of the aircraft’s structure than its weight percentage suggests. The composite material not only forms the aircraft’s skeleton but also much of its body. The remaining 50% of the weight is concentrated in high-density areas, where metals remain superior, such as landing gear (steel/titanium), engine components (titanium), and fasteners.

Aluminum is used primarily for the leading edges of the wings and tail, as well as parts of the engine inlets. Leading edges are highly susceptible to bird strikes and hail. Aluminum is ductile, meaning it tends to dent and absorb energy during an impact, whereas composites can delaminate or shatter upon high-speed collision. The 787 uses electrical heaters for anti-icing. Aluminum conducts heat much more efficiently than composite materials, allowing for effective melting of ice at the wing’s front edge.

Titanium is the « heavy-duty » partner to the 787’s composite frame, used for the engine pylons, exhaust sections, and critical fasteners. Jet engines and the auxiliary power unit (APU) in the tail produce extreme heat. While the carbon fibers in composites can handle high temperatures, the plastic resins holding them together melt at roughly 300°F–400°F. Titanium remains stable even at temperatures exceeding 1,100°F (600°C).

Steel is reserved for parts that require extreme hardness and absolute strength in a compact space, primarily the landing gear. Landing an aircraft puts immense pressure on a relatively small structure. High-strength steel alloys can handle these massive, sudden loads better than any other material. Moving mechanical parts, such as the gears and cylinders in the landing gear, require the extreme hardness and wear resistance that only steel can provide for long service life.

A Worldwide Production Effort

Boeing South Carolina (BSC) in North Charleston is now the exclusive global assembly hub for all three variants of the 787 Dreamliner. As of late 2025, the facility is undergoing a massive transformation to meet surging global demand. The facility is scaling production from approximately seven aircraft per month in early 2025 to a target of 10 per month by 2026.

The 787 relies on a global partner model, where major sections arrive at the factory already pre-assembled from around the world. The wings, center, and forward fuselage sections are manufactured in Japan by Mitsubishi, Kawasaki, and Fuji Industries before being transported to the USA. Horizontal stabilizers in central fuselage sections are manufactured in Italy by Leonardo and Alenia.

In France, Safran and Latecoere build the landing gear and passenger doors. In India, Tata and Mahindra produce the floor beams and engine inlet components. Meanwhile, Korean Aerospace Industries makes wingtips in South Korea. Spirit AeroSystems makes nose components in Kansas, as well as forward fuselage sections.

To bring all these parts together to the final assembly line (FAL), Boeing uses a specially modified 747-400 named the Dreamlifter. The extra-large version of the jumbo jet has a hinged tail section that swings open with the tailplane and allows exceptionally large components, such as entire pairs of wings, to be loaded and flown from one continent to another.

From Novelty to Industry Standard

It took the legendary planemaker, Boeing, years to develop the technology necessary to construct the 787 Dreamliner. The plane was the first clean-sheet design in over a decade, otherwise known as starting from the drawing board, with the explicit purpose of overcoming the physical and economic limitations imposed by traditional aluminum aircraft construction. The radical composite technology implemented in the Dreamliner was a game-changer, and the plane has become one of its most important products in the modern era.

In another interesting piece of trivia tied to the Dreamliner program, a significant portion of the technology that ultimately matured for the production of the 787 was originally conceived under the “Sonic Cruiser” development, which was intended to compete with the Concorde, but was ultimately canceled in 2002. The ill-fated program never produced a supersonic airliner, but it did lay the foundation for what is now the best-selling widebody aircraft ever made.

While the carbon fiber composite material was not invented for the 787, its use in mass-scale production had never been seen before. In fact, the Dreamliner was largely inspired by carbon fiber progress made on the 777 program, which saw limited implementation. The 787 took that to the next level, instead of using the invaded material for novel components, it made it the primary material throughout its aerostructures.