Everett - The first 777-9 is taking shape for flight testing. Boeing has installed the foldable wing mechanism on the prototype WH001. The first flight to take place in March 2019.

Despite its huge wingspan of 72 m on the flight, the 777X is considered as an "ICAO Type E" aircraft thanks to its foldable wing tips reducing the aircraft's wingspan from 72m (236ft) to 65m (213.2 ft) on the ground. Boeing has been holding a patent for the newly implemented folding mechanism since 1993.

Instead of aluminum, Boeing uses lightweight and highly stable carbon fiber composites for the wings of its new widebody.

In May, the US aviation authority FAA had issued special licensing requirements for the Boeing's folding mechanism. Automatic, multiple safety warning systems are designed to prevent a 777-8 or 777-9 from taking off with raised wing tips. During the flight, the system must not unlock under any circumstances.

Boeing releases more photos of the very first Boeing 777X

Video: Folding wing of the Boeing 777X is ready for testing

The FAA also requests evidence that the wing tips are capable of withstanding wind gusts of up to 65 nautical miles (120 kilometers) per hour on the ground.