Boeing added a pair of new flight test aircraft to its 787 and 747-8F certification programmes on 14 March.
ZA003, the fourth 787 to fly, and RC522, the second 747-8F to fly, took off from Paine Field in Everett, Washington 5h 2min apart, at 10:55 PDT (18:55 GMT) and 15:57 PDT (23:57 GMT), respectively.
ZA003, flown by Captains Ray Craig and Mike Bryan, spent 3h and 5min flying over Washington state and reached an altitude of 29,000ft (8,840m) and landed at 14:01 PDT (22:01 GMT).
The aircraft, which will primarily test the 787's passenger environment, includes racks of instrumentation sandwiched between two sections of seats, stowage bins, galleys and overhead crew rest areas.
In addition the aircraft will test the 787's flight deck operations, avionics, electromagnetic effects, high-intensity radio frequency response and extended twin-engine operations (ETOPS).
ZA003 is the last of four Rolls-Royce Trent 1000-powered test aircraft, and the fourth of a total of six in the 3,100h test flight campaign expected to culminate in delivery of the first 787 to Japan's All Nippon Airways in the fourth quarter.
Boeing kicked off its flight test programme on 15 December 2009, when ZA001 made its maiden sortie.
RC522, which is the last of three 747-8F test aircraft built, but the second to fly, was flown by Captains Kirk Vining and Rick Braun and reached an altitude of 27,000ft and an airspeed of 240kt and touched down at 18:25 PDT (2:25 GMT) after a 2h and 27min flight.
RC501, the first 747-8F, made its first flight on 8 February and completed its initial airworthiness testing on 11 March.
"The airplane performed well on its first flight," Andy Hammer, Boeing test programme manager for 747-8, says in a statement. "It was a good start to a demanding flight-test program for this airplane."
The aircraft will eventually be delivered to Nippon Cargo Airlines following the flight test programme, which will see RC522 focusing on community noise, environmental control systems and extended operations performance standards.
Both flights ended at Boeing Field in Seattle.