Boeing is studying raising the production rate of the 737 family to an unprecedented 31 a month, as an era at its Renton, Washington plant comes to an end with the delivery of the last 757.

The output evaluation comes in the wake of a recent order surge, increasing backlog waiting times and implementation of improved production efficiencies. The company, which traditionally does not comment on production rates, admits "we are definitely feeling pressure from the market to increase rates", and adds that "we have a robust production planning process, so none of what is happening is a complete surprise".

The rate of 31 a month is believed to represent as much as six additional aircraft each month over the current rate, which was achieved after Boeing at the start of this year implemented an 11-day assembly flow for the first time at Renton. This marked the culmination of moving-line and other final-assembly improvements that began in late 1999.

The 737 line was at its all-time highest rate in mid-2001, when it reached 28 a month just before the 11 September attacks, after which Boeing immediately slashed production rates by around 50%.

Impetus for the rate rise comes from a recent flurry of orders from predominantly low-cost carriers, as well as the imminent prospect of additional military airframes to support the US Navy's P-8A Mult-mission Maritime Aircaft programme. The current firm-order backlog, adjusted for 13 new net orders taken in April and assuming around 24 deliveries for the month, is roughly 770 aircraft. This is expected to be bolstered by a further 108 aircraft when the production order for the P-8A is ratified.

The initial MMA airframe, for which Boeing is contracted, is expected to make its first flight in 2008, and to be delivered in 2009.

Meanwhile, the 1,050th and final 757 was handed over to Shanghai Airlines last week. The aircraft was the second of two that has been held in short-term storage since being the last to roll off the Renton assembly line in late 2004. The last 757, of which more than 1,030 are still in service, is the first of its type to be certificated and delivered to Chapter 4 noise standards, which take effect from 1 January 2006.

GUY NORRIS/LOS ANGELES

Source: Flight International