Boeing (NYSE: BA) has completed installing reinforcements within the side-of-body section of two more 787 Dreamliners.

Over the weekend, employees at Boeing’s facility in Everett, Wash., finished reinforcing the full-scale static test airframe and the second Dreamliner designated for flight test. Installations were completed Nov. 11 on the first flight-test airplane.

The modification entails installing new fittings at 34 stringer locations within the joint where the wing is attached to the fuselage.

“Our focus now is on completing the static test later this month, which will validate the modification,” said Scott Fancher, vice president and general manager of the 787 program. “Concurrently we are restoring the airplanes and completing the functional tests required to fly by the end of the year.”

The static test airframe is being refitted with strain gauges and instrumentation required for testing. Access doors, systems, seals and fasteners removed from airplane No. 2 to provide access are being restored in preparation for continued testing on the airplane. The first 787 also is being restored.

Fancher said the program is on track to fly the 787 by the end of the year.

“We are building momentum with each milestone we achieve,” Fancher said. “This team is focused on its goals and bringing us ever closer to first flight.”