Speeding 737 production

Wing panels are built from skins and stiffeners called stringers. Skin panels are placed on the tool at the first station. The stringers arrive in a harness system that allows the monorail to carry them in a prearranged order to be fastened to the skins.

A Panel Assembly Line (PAL) machine moves along the tool indexing, drilling, and partially riveting and bolting the skin and stringers together in a day.

A second PAL machine finishes the riveting and bolting as it moves along.

Mechanics attach wing-to-body pieces to the panel.

The panels are inspected, then sent to be sealed. An overhead crane moves finished panels to the wing assembly line.

Front and back spars are attached to ribs making a wing box.

The upper wing panel attached to top of the wing box.

AGVs (Automated guided vehicles) carry the wing box to a tool that holds it. AGVs then bring over a lower panel, and a machine drills and fastens it to the wing box.

The wing box, underfittings, trailing and leading edges, and main landing-gear beam are assembled. The wing is then cleaned, sealed and inspected before being painted.

After painting, the spoilers, flaps, slats and flight controls are added. The winglets are bolted on. Finished wings are moved to final assembly.

Fuselage shells built in Wichita, Kan., are shipped to Renton by train, unloaded onto trailers and brought into the factory. An overhead crane lifts each fuselage into one of three 450-foot-long systems-installation lines.

A rail system moves the fuselage shells from one position to the next each night when work is completed.

As the fuselages move down the line, mechanics install most of the permanent flooring, electrical and hydraulic systems, plumbing, and insulation blankets, then attach the overwing doors and radome.

Finished fuselages are lifted by crane over to final-assembly lines.

Lasers align the wings with the fuselage before they are attached. The landing gear is attached.

Horizontal and vertical tails are attached along with the pre-painted rudder. The flight controls are connected.

Sidewalls, seats, lavatories, galleys, overhead storage bins and other interior items are installed as specified by the buyer.

Functional test occurs sequentially as the airplane is built. Engines are attached, fueled and run. The plane is ready for paint. It takes three to seven days to paint a 737.