Boeing 737 NG

Boeing announced it has begun building the first 737NextGens at a rate of 35 aircraft per month, up from 31.5 airplanes a month, to meet demand.

The 737 production rate will increase to 38 a month in the second quarter of 2013 and to 42 a month in the first half of 2014, Boeing said.

Boeing has orders for 310 737s for 17 airlines, according to its orders and deliveries website. It has sold 9,134 737s of all 737 models up to Sept. 30 and has delivered 6,919 up to the same date.

Tuesday it was revealed that China Eastern Airlines (MU) canceled its order for 24 787s and placed a new order for 45 737s (ATW Daily News, Oct. 18).

To prepare for the rate increases, Boeing said it has improved production processes, increased capacity through investments in a new wings system installation line in its Renton, Wash., factory, and made the site footprint more efficient by moving some production areas, expanding others and decommissioning outdated equipment.

Boeing has rolled out its first factory-complete 737 under a new production rate of 35 per month, a record for the company's Renton, Washington factory.

The aircraft, intended for delivery to all-Boeing operator Norwegian Air Shuttle, left the company's final assembly line on 4 December. First flight and functional testing will be performed at the adjacent Renton Municipal Airport.

To assist in advancing the rate, Boeing split its electrical systems installation on its 737 wingboxes into two dedicated lines, one for the left and right-hand wings with dedicated teams for each to reduce variability that previously slowed production.

Boeing expects to achieve two additional rate breaks in the coming years, with further increases of 38 per month in the second quarter of 2013 and 42 per month in the first half of 2014.

Boeing first achieved a previous record rate of 31.5 aircraft per month in the third quarter of 2009, up from 31 per month.

Boeing will add seven inches of space to its 737NG with an improvement unveiled in 2014, it told journalists at a pre-Farnborough briefing in Seattle, Wash. The improvement adds a new slimline lavatory, featuring an “s-wall” in the cabin, allowing airlines to either reconfigure their interiors for improved comfort, or for extra seats.

“Some airlines are reconfiguring their interiors and gaining three additional seats,” 737 VP and GM Beverly Wyse said.

The improvement will be basic on the 737 MAX.

“We’re seeing many of our airlines coming in and reconfiguring the amount of galley space they have, restructuring their pitch throughout the cabin, constantly balancing the amount of premium and economy cabin,” Wyse said. “We are seeing airlines getting additional seats over today’s configurations.”

Wing Join" Aviation Week, 5 June 2006

Space for the -900ER's additional seating is courtesy of a composite flat rear pressure bulkhead
manufactured by Spirit Aerosystems. The traditional domed bulkhead is lighter by 400 lb. but its curved
surface reduces the interior's usable space by at least a full row of seats. With the flat bulkhead, the -
900ER's rear cabin can be configured in a popular layout of two lavatories with eight galley carts or a
single lavatory with three galley carts but more floor space.

Also quoted there:

JAPAN AIRLINES has exercised an option for the flat rear pressure bulkhead on its 737-800 order

The enhancement package consists of elements that can be applied to the longer- body -800/900ER, as well as a wider set of improvements that can be offered for family members. Specific to the -800/900ER are sealed slats for all take-off flap positions, and a two-position tailskid. On current aircraft, the slats are sealed for take-off flap positions 1° and 5°, and are gapped for 10°, 15°, 25° and over. The change will see the sealed positions extend through 25˚ flap.

Generic 737NG configuration changes include Krueger flap seal actuation to allow the device to be “left sealed for take-off and up out of the way [open] for approach and landing,” says Delaney. Flight-spoiler deflection on the ground will be increased from 30˚, to match the maximum 60˚ of the ground spoilers. The operation of the flight spoilers in normal flight will be unchanged, he says. “But when it lands all the spoilers will come up to a nominal 60˚ throw for greater braking performance.”

Another subtle change across all models will be a reduction in the camber, or “splay” of the main landing gear. “We’ve brought it in by just over 1°, which increases the uniformity of braking across all four brakes and will help tyre [wear] issues we’ve seen across the fleet. It’s a maintenance benefit,” Delaney says. Also changing will be the engine idle thrust delay time, which is being reduced from 5s to 2s. The change, effected through the CFM56-7B’s full-authority digital engine control, will “bring forward idle thrust off the aircraft faster”, thereby helping shorten the landing roll.

The Krueger flap change is applicable to all models and will boost landing performance, as will the idle thrust delay change. The increased flight-spoiler deflection, also applicable across all models, will improve take-off and landing. The -800/900ER-specific changes will boost take-off performance in the case of the leading-edge slat seal change, and landing in the case of the two-position tailskid.

Boeing expects the package to reduce the typical landing run of a winglet equipped -800 by up to 100m, or increase the landing weight by as much as 4,730kg, while the take-off length could be reduced by more than 70m or the take-off weight boosted by more than 1,710kg. For the winglet equipped -900ER, take-off run will be cut by around 85m and weight boosted by more than 1,815kg.

The three-month flight-test effort is expected to run through to late April, with delivery of the first fully equipped aircraft around mid-June. “The changes are designed to be more or less transparent to the crew, so a pilot can be in a -700 in the morning, a -900ER in the afternoon and a -800 short-field at night and all the procedures are the same,” says 737 chief pilot Ray Craig.

Boeing is also offering carbon brakes as a no-charge option for the first time on the Next Generation. “Around one-and-a-half years ago we surveyed carbon-brake technology again and saw that maintenance cost per landing was coming down and that operators would benefit from it without paying a penalty in terms of turnaround time,” says Delaney, who adds: “It was the fifth time we’d studied it in the life of the Next Generation.”

Short-field Performance Enhancement Program

The Short Field Performance improvement package was developed in 2005/6 to allow GOL airlines to operate their 737-800s into the 1,465m (4,800ft) Santos Dumont airport. The modifications enable weight increases of approx 4,700kg (10,000lbs) for landing and 1,700kg (3,750lbs) for take-off from short runways. It includes the following changes:

• Flight spoilers are capable of 60 degree deflection on touchdown by addition of increased stroke actuators. This compares to the current 33/38 degrees and reduces stopping distances by improving braking capability.
  
• Slats are sealed for take-off to flap position 15 (compared to the current 10) to allow the wing to generate more lift at lower rotation angles.
  
• Slats only travel to Full Ext when TE flaps are beyond 25 (compared to the current 5). Autoslat function available from flap 1 to 25.
  
• Flap load relief function active from flap 10 or greater.
  
• Two-position tailskid that extends an extra 127mm (5ins) for landing protection. This allows greater angles of attack to be safely flown thereby reducing Vref and hence landing distance.
  
• Main gear camber (splay) reduced by 1 degree to increase uniformity of braking across all MLG tyres.
  
• Reduction of engine idle-thrust delay time from 5s to 2s to shorten landing roll.
  
• FMC & FCC software revisions.
  

The SFP package has now become an option on all 737-800s (known as 737-800SFPs) and standard on the 737-900ER. Some of the features may also be fitted to the 600/700 series. The first SFP was delivered 31st June 2006.