The Boeing 787-10 took-off about 09:38 on 31 March in North Charleston, South Carolina in front of an audience of 6,000 employees, becoming the first Boeing-designed commercial aircraft to achieve first flight outside of the Seattle area.
The 787-10 will now enter a months-long flight test campaign to achieve certification and enter service with Singapore Airlines in 2018.
Boeing stretched the 787-10 by 5.49m (18ft) compared to the 787-9, requiring the addition of a semi-levered landing gear to avoid tail-strikes on takeoff.
The first test aircraft is powered by the Rolls Royce Trent 1000-TEN, featuring a 75,000lb-thrust rating.
Otherwise, the 787-10 was designed to be 95% common with the 787-9.
Boeing will assemble the 787-10 exclusively in North Charleston. Assembly for the 787-8 and 787-9 is split between North Charleston and Everett, Washington.