A Boeing 747-8 freighter waits on the flight line before making its first test flight at Paine Field in Everett, Washington. Boeing Co.'s giant 747-8 freighter -- the biggest plane the company has ever built -- successfully completed its first flight Monday, a year later than originally planned. [Photo: Xinhua]

Boeing Co.'s 747-8 freighter successfully completed its first flight on Monday, the U.S. aerospace giant said.

More than 5,000 employees, customers, suppliers and other guests witnessed the moment when the jumbo jet, the biggest plane Boeing has ever built, took off shortly after noon local time from Paine Field Airport in Everett in the western state of Washington, one day before the 41st anniversary of the first flight of the 747.

The flight lasted three hours and 39 minutes as the plane followed a route over western Washington, where it underwent tests for basic handling qualities and engine performance, Boeing said in a press release.

The 747-8 freighter is 76.3-meter long, 5.6 meters longer than the 747-400 model. The stretch provides customers with 16 percent more revenue cargo volume compared with its predecessor, according to Boeing.

The company said the jet is more eco-friendly than the current 747-400 model, calling it "the world's most efficient freighter."

Boeing is also developing a passenger version of the 747-8, seen as a competitor to Airbus A380, the world's largest passenger jet though both the 747-8 freighter and passenger jets are smaller than A380.

The 747-8, listed on the market for some 300 million U.S. dollars, was launched in November 2005 and was originally scheduled to take its first flight in 2009.

However, the first flight and first deliveries of 747-8 freighter and passenger jets have been delayed due to limited availability of engineering resources, design changes and other reasons.

First freighter model of 747-8 is now expected to be delivered by the end of 2010, followed by the first delivery of the passenger version a year later.

Boeing said it has secured 108 orders for the 747-8, of which 76 are orders for the freighter model.

Cargolux, Nippon Cargo Airlines, AirBridgeCargo Airlines, Atlas Air, Cathay Pacific, Dubai Aerospace Enterprise, Emirates SkyCargo, Guggenheim and Korean Air all have ordered the 747-8 freighter, according to Boeing.