Carbon fibre, more lightweight, durable and resilient than aluminium and steel, is widely used in aircraft. This enables fuel economy and a great degree of freedom in design.
An ordinarily narrow fuselage becomes more voluminous and curved to enhance streamlining, greater passenger comfort and technical convenience. Reliable engines do not require constant monitoring, so it is better to partially embed them in the body. Wings are made longer and thinner to reduce drag and, once again, to save fuel. The back of the aircraft models becomes U-shaped, acting as a shield for the engines and reducing their noise.
Lightweight composite materials make it possible to use more environmentally friendly forms of energy. Aircraft with engines that are powered exclusively by solar panels located on their wings are no longer a rarity.