Boeing uses folding wings on new 777X model to meet airport limits

The folding wingtips are also a response to airport infrastructure constraints. International Civil Aviation Organization (ICAO) Code E regulations limit wingspans for certain airports. By incorporating folding wingtips, Boeing ensures that despite its extended wingspan during flight, the aircraft can fit within Code E gates when on the ground. This avoids operational restrictions faced by larger aircraft like the Airbus A380, which falls under Code F and requires special airport accommodations.

Folding wingtips present engineering challenges. They add complexity through more moving parts and increase maintenance requirements. The mechanisms also add weight, partly offsetting savings from advanced lightweight materials such as carbon fiber-reinforced polymer (CFRP). However, CFRP’s flexibility helps mitigate some of these drawbacks.

"Perhaps the biggest and most costly penalty for Boeing is the delays in FAA certification. The FAA is requiring rigorous testing of the folding wingtips, and this is contributing to pushing back the 777X's expected introduction date to late 2026. It is unclear how much of the delays are due to the wingtips specifically, and how much is due to other issues, including shaken confidence in Boeing following the Boeing 737 MAX crashes of 2018 and 2019."

Boeing initially considered longer folding wingtips for earlier versions of the 777 but opted for shorter ones in order to reduce complexity and weight. The current design features an approximately eleven-foot fold at each tip.

The commercial success of the Boeing 777X relies heavily on orders from Emirates and Qatar Airways, with no North American carriers having placed orders so far. Despite trade-offs related to added weight and certification delays, Boeing expects that increased efficiency will give it an advantage over competitors like Airbus.

The use of folding wingtips allows engineers to optimize wing length for better performance while still complying with global airport standards—a compromise that may influence future widebody aircraft designs across manufacturers.