The Boeing 747-8 Freighter took to the air for its first flight today from Paine Field in Everett, Wash., at 12:39 p.m. PST, marking the start of a flight-test program scheduled to last until near the end of this year. The first of three 747-8 prototypes built for the program took off some two and a half hours later than originally planned due to a low cloud ceiling over Paine Field this morning. Plans called for a three- to four-hour test mission, during which program chief pilot Mike Feuerstein and senior test engineer Tom Imrich expect to perform basic handling and engine performance testing, according to a Boeing spokesman on the scene.

Originally planning to deliver the first freighter by the end of last year, Boeing’s 747-8 program team struggled through a series of delays related to production problems, a shift in resources to a troubled 787 program and what Boeing CEO James McNerney described as a lack of engineering maturity. Boeing now plans to deliver the first 747-8F to launch customer Cargolux some time near the end of this year and the first passenger version to Lufthansa in the fourth quarter of next year.