In the first stage of its eventual plan to increase 737 production rates to record levels of 42 aircraft a month and beyond, Boeing is readying the wings of the first aircraft that will be assembled at the faster rate.

The move comes as Boeing confirms it is studying raising the overall rate to as much as 52 per month in the 2018-2019 period when the current 737 Next Generation will begin to phase out as the 737 MAX takes over.

Commenting in Seattle on Feb. 4, Boeing 737 vice president and general manager Beverly Wyse says the higher-rate option is being considered if the current market holds. The option is being explored with suppliers, she adds.

The company, which currently makes 38 737s per month at its Renton, Wash. facility, is eager to boost assembly rates as quickly as it can to deliver the huge order backlog. At the start of 2014 this stood at 3,680 aircraft of which more than 1,900 are 737NG. The balance of the backlog is made up of 1,763 orders for the MAX family, first deliveries of which are set to begin in 2017. The bulk of the undelivered 737NGs are 737-800s of which around 1,450 remain in the backlog with 4,551 already delivered.

The wings starting assembly at the higher rate will be installed on an aircraft for delivery in the second quarter, marking the official transition to the 42 per month production rate. A further push to 47 per month is due to start in 2017.

Boeing adds that with the latest increase production of the 737 has increased by 33% since 2010. The rate increase will begin when wing spars are loaded into an automated spar-assembly machine on Wednesday.