Boeing 777X's Folding Wingtips Cut Its Span from 71.75 m to 64.85 m, Keeping It in ICAO Code E
Why It MattersFolding wingtips let manufacturers add wing span for efficiency without forcing airports to rebuild gates and taxiways, a constraint Airbus is now testing its own answers to.
Boeing's 777X has the widest wingspan of any Boeing model, at 71.75 meters. A span that size would place it in ICAO aerodrome size F, alongside heavy aircraft such as the Airbus A380 and Boeing 747-8, and would limit it to airports with facilities for such large aircraft. To avoid that, Boeing fitted the 777X with folding wingtips. With the tips retracted, the span is 64.85 meters, which keeps the aircraft in size category E, the same as existing 777 models. Hydraulic actuators move the tips in roughly 20 seconds, and they are locked in position before takeoff.
Airbus is exploring a different approach with its AlbatrossONE demonstrator, a small-scale, remote-controlled aircraft with semi-aeroelastic wingtips hinged so they can flap freely in flight. The aim is to reduce the effects of turbulence, avoid wingtip stalls on landing and possibly improve roll rate. The tips can be locked flat for climb and cruise, locked in a 10-degree raised position for landing, or stowed fully upright to save space at the gate. Airbus has not taken the concept to the commercial stage reached by the 777X.
Airbus's eXtra Performance Wing project, launched in September 2021 and led by subsidiary UpNext, builds on this work. Its demonstrator is a modified Cessna Citation VII business jet with a 16-meter wingspan, about one-third scale of a design targeting a span of more than 50 meters; an A320 spans 35.8 meters. The hinged wingtips are meant to keep the aircraft within the 36-meter gate limit on the ground and flex in flight to relieve load on the wing, while allowing a longer span for more lift and less drag. The demonstrator made its first flight in November.
