Boeing's new long-haul 777X airliner made its first flight on Saturday, a step forward for the company whose broader prospects remain clouded by the 737 Max crisis.

The world’s largest twin-engine aircraft landed at Boeing Field near Seattle after approximately four hours in the air, following months of delays and erratic weather in recent days.

High winds led to the maiden flight’s postponement on Friday, and the company blamed the weather for an earlier delay on Thursday, which was rainy.

A few minutes after 10:00am local time (1800 GMT), the plane took off from the rain-slicked runway at Paine Field in Everett, Washington, home to Boeing’s northwest US manufacturing site.

“Yes!” Boeing spokesman Josh Green shouted as the plane’s wheels finally lifted off the tarmac.

Just minutes earlier, the pilots deployed the plane’s winglets – folding wingtips – designed to improve the craft’s fuel efficiency and make it possible for the plane, with the widest wingspan ever from Boeing, to be accommodated at more airports.

The first flight was originally scheduled to take place in mid-2019 but was postponed due to problems with the new engine, manufactured by General Electric, and difficulties with the wings and software.

Saturday marked the first of what is to be a series of in-flight tests. If they go well, Boeing will officially file for approval from the Federal Aviation Administration.

With Boeing facing a crisis over its top-selling 737 Max following two deadly crashes, the 777X is supposed to compete in the long-haul aircraft market with the A350 made by rival European aircraft manufacturer Airbus.

The flight was “a demonstration to the world that we know what we are doing. We know how to design aircraft and instil trust in the public”, said Boeing Commercial Airplanes president and CEO Stanley Deal.

Major airlines including Emirates, Lufthansa, Cathay Pacific, Singapore Airlines and Qatar Airways have placed some 340 orders for the 777X.

The first deliveries of the new model, with a maximum capacity of 384 to 426 passengers depending on the configuration, are not expected before early 2021, instead of mid-2020 as initially planned.

The aircraft encountered significant problems during pressurisation tests in September.