Boeing has increased the production rate on its 737 line to 35 aircraft per month as it transitions to 42 per month by 2014.
The first aircraft to be produced at the higher rate is destined for Norwegian Air Shuttle and is at position four on the Renton factory's line two.
It will hit 38 aircraft per month by the second quarter of 2013, and 42 each month after that, said Erik Nelson, head of 737 production at Renton.
Modifications inside the Renton factory are ongoing, with additional space to be created on line two to increase its capacity to 14 per month from the present rate of 10.5. The adjoining line one is already producing 21 aircraft per month, said Nelson.
Changes already undertaken include moving the final assembly of vertical and horizontal stabilisers from the wing assembly area to the main production line.
"It's a large logistical challenge around making sure all the suppliers are ready," he said. "But we have been working diligently at this for quite some time."