Boeing employees have started assembly of the first 737 MAX – precisely on time. Assembly of the first 737 MAX in Boeing's Renton, Wash. facility kicks off with wing assembly for the first 737 MAX flight test airplane. The wings will be attached to the first 737 MAX fuselage later this year.

The Renton team commemorated the first spar load, which is a milestone toward which the program accelerated three years ago and achieved on the exact day it was scheduled to begin.

"Three years ago, the plan said we were going to load the spar on May 29, 2015, and here we are," Keith Leverkuhn, vice president and program manager of the 737 MAX program, Airplane Development, told employees at a celebratory event. "Achieving this milestone production start on schedule is a testament to the success of the 737 and our integrated design and build team."

Earlier in May, the Renton team also started work on the upper and lower wing panels in the new panel assembly line (PAL) that uses automation to drill holes and install fasteners in the upper and lower wing panels. The unfinished skins, stringers and spars were machined by Boeing Fabrication Skin and Spar in Auburn and Fredrickson, Wash. When finished, the panels and spars will be transformed into completed wings.

"It's really exciting to be starting something that you know is going to be in the future and that you are going to be building," said David Dowell, a 737 mechanic on the new panel assembly line. "I'm looking forward to it and future growth."

The 737 MAX wing design is similar to the Next-Generation 737 wing. It is still made mostly of aluminum but with increased gauges and stronger materials to accommodate increased weight of the new, more fuel-efficient LEAP-1B engines for the 737 MAX and some revised system requirements.

The wings will be attached to the first 737 MAX fuselage on the new Central line in Renton Final Assembly later this year. The new line will allow the team to isolate the first 737 MAX being built from the rest of production, in order to learn and perfect the build process, while the Renton factory continues to build at a rate of 42 airplanes a month.

"Employees in Renton are the best in the world at building single-aisle airplanes, and now this world-class team is building the future with the first 737 MAX," Leverkuhn said.

By Lauren Penning