The aviation industry is looking for new projects to reduce carbon emissions and improve aircraft efficiency.
One idea is to make the wings part of the fuselage to reduce drag and noise.
Another proposal is to use advanced composite materials to make the aircraft lighter.
The Dutch company KLM is investing in a new concept, the 'Flying-V', developed by the Delft Technical University, seeks to divide the aircraft into two sections towards the rear, combining the body with the wings.
This will give the aircraft the same scope as Airbus' A350, which can carry 314 passengers, "but consuming 20 percent less fuel," the airline said in a statement.
The International Air Transport Association is also evaluating two new smaller aircraft projects that could carry up to 150 passengers and start operating in 2035.
One of the concepts involves joining the wings with the back of the aircraft and installing two engines on the body of the aircraft.
Like New design, the aircraft could reduce carbon emissions by 30%.
The other is to build a fully electric airplane with engines inside the wings powered by batteries or fuel cells – the wing tips would be turned inward to improve aerodynamic efficiency.