FLUG REVUE January 2003: Boeing 777-300ER rolls out

BOEING 777-300ER ROLLS OUT

By Sebastian Steinke

Alan Mulally, President and CEO, Boeing Commercial Airplanes, beamed from the light of the big screen, as he pronounced, "This is absolutely the coolest aircraft in the world… It is the realisation of a vision born 14 years ago to expand the 777 programme into a family of aircraft for our customers that would be especially safe and economical.” Then, before an audience of 4,000 guests, including many high-ranking airline representatives, he formally unveiled the star of the day, illuminated in the glistening ramp lights – the first 777-300ER.

Boeing 777-300ER

As one contemplated the conspicuously "red carpet treatment” which Boeing had lavished on the latest 777 on the occasion of its roll-out in Everett, one could not help feeling that the huge twinjet is intended to fulfil a certain flagship role among the Boeing products. In response to a question from FLUG REVUE as to whether the ever-growing 777 was not becoming increasingly an in-house rival to the Boeing 747, Mulally admitted with surprising frankness that "precisely that was our intention right from the start.” However, he added that there were no plans to develop a further stretch of the 777 into a 777-400 in the immediate future.

At Boeing they are particularly proud of the 777, since, compared with the approach taken on many of the company's big sellers, such as the 737NG and the 747-400, the "Triple Seven” was not simply a revision of an existing successful model, which would have meant substantial cost and risk reduction, but was a completely new design. The 777 was developed as an aircraft with the same fuselage cross-section and dimensions as the jumbo jet, but with only two engines, which therefore had to be very large and fall into a completely new category.

To fully appreciate the performance capability of the powerful 777 turbofans, it is necessary to view these gigantic power plants, whose diameter is no less than that of a full Boeing 737 fuselage, from close up. To power the new 777-300ER, with its 340 tonne take-off weight, the thrust produced by the two new GE90-115B turbines, the only engines on offer, had to be raised to the world record of 511kN.

Boeing is promising seat mile costs with the twin-engined 777-300ER that are between 15 and 18% below those of the four-engined A340-500 and A340-600 competing Airbus models. Fuel consumption per seat, we are told, will be as much as 21 to 22% better.

Following the programme launch in 1990, the initial version, the 777-200, has also been available since 1995 in a stretched version, the 777-300, and this latest version incorporates still further improvements in payload and range. To date over 600 Boeing 777's have been ordered by 30 customers.

Compared with its stretched sister model, the 777-300, the 777-300ER has 2,400km of extra range, giving a total of 13,427km, and can carry 19,700kg of freight in the lower deck as well. This makes it suitable for long-distance routes such as Paris-Los Angeles or Tokyo-New York. In particular, Asia is viewed as an important potential market for the new ER version, with its high capacity on trans-Pacific routes.

However, for flights lasting up to 14 hours, the 777-300 needs crew recreation areas for standby pilots and flight attendants. To avoid either using up valuable space on the main deck or filling up the lucrative cargo bay with fittings, Boeing can relocate the crew rest area, if required, to the "crown” above the main deck. While the pilots have two seats and two beds above First Class, the cabin crew are accommodated in modular deck compartments for between six and ten flight attendants above the Tourist Class section. To fit these facilities into the previously unused space above the cabin, parts of the pipe system for the air-conditioning had to be re-located. Both the future 777-200LR (16,400km range, up to 18 hours' flying time) and new sales of the familiar 777-200ER (14,300km range) can also be fitted with the new crew recreation areas, if required.

Extensive remodelling has been carried out on the wings of the 777-300ER. In addition to structural reinforcement and new mounting brackets for the more powerful engines, Boeing has also created additional space on the wings to accommodate bigger wing tanks. To optimise fuel consumption, the ER has the same raked wingtips that are already familiar from the 767-400.

An additional shock absorber enables the semi-levered undercarriage of the 777-300ER to be locked in position on take-off so that at rotation the aircraft is still supported until the very last-minute on the back pair of wheels without their giving way at all. By this means, if the extremely heavy plane should only rotate at a relatively high angle of attack, the stretched fuselage is prevented from coming into contact with the ground. In addition, automatic movement of the elevator prevents the rear from touching the ground on take-off in the event of excessive control inputs by the pilots. Despite this, Boeing has retained the small tailskid bumper under the tail section, as FLUG review was able to ascertain on a walk around the first 777-300ER.

Again, the ER's nose gear has a surprise up its sleeve, but only when the aircraft is stationary. Thanks to a retractable nose gear strut, an extremely heavily laden 777-300ER can be maintained in a horizontal position when parked, instead of being somewhat nose-heavy, as would otherwise be the case. This means it will be possible to operate the existing freight lifting platforms at airports without any problems and without any need for modifications. Wheels and brakes are otherwise the same as on the Boeing 767-400.

The two engines have unusually deep, strikingly S-shaped swept compressor blades, whose diameter has grown by 12.7cm, while the external dimension, which is important for transporting replacement engines in cargo aircraft, has only grown by just under 4cm. The new blades will generate 8.9kN of extra thrust and also reduce fuel consumption.

On the first test runs, kerosene consumption was actually half a per cent below expectations, as Chaker Chahrour, General Manager for the GE90 programme at engine manufacturer General Electric, explained at a press conference in Seattle. Compared with the GE90-94 engine on smaller versions of the 777, although only 30% of parts on the GE90-115B are identical, 80% of the design and as much as 90 to 95% of the tooling for the two engine variants are the same.

After 22 test flights with a GE90-115B on GE's own Boeing 747 and 110 hours of testing, the new engine has already proved itself. Apparently on one test flight, the GE 747 even took off relying solely on the power of its single experimentally mounted GE90-115B and climbed to an altitude of 10km while the three other engines on the 747 were idling. Apart from a slight improvement to the cooling in the first compressor stage, no other changes have been made. The goal GE has set itself is that the engine, which is expected to be certificated in December, should have an on-wing time of 20,000 operating hours between services.

According to Chahrour, the manufacturer is expecting a market of 500 aircraft for this, the most powerful commercial engine in the world. The aircraft in question are the 777-300ER, to be followed later on by its shorter, ultra-long-range sister version, the 777-200LR. This implies a minimum of 1,100 engines, which at present come with a price tag of $21 million each.

The opportunity has also been taken to introduce extensive modernisation in the cockpit and the avionics: LCD screens instead of CRTs, ground cameras beneath the fuselage and on the elevator for monitoring taxiing and electronic processor modules to the latest AIMS-2 standard from Honeywell ensure that the 777 is state-of-the-art.

The 777 is already a fly-by-wire aircraft, that is, the pilot's control inputs to the rudder, spoilers and leading edge flaps are electronically filtered and passed on via a computer. Unlike Airbus, Boeing has implemented "soft limits”. This means that the pilot can override the limits set by the computer when he sees fit. The chip used in the 777's primary flight computer comes from Europe, and is manufactured by BAE Systems.

For the first time Boeing will be offering the option of a "paperless cockpit” from October 2003 for all 777's. Two extra screens in the cockpit below the window frame will provide pilot-selectable displays of Jeppesen airport maps, pages from the maintenance manual and other additional information which up to now has meant that pilots had to take vast quantities of paper documents on board with them. The new computer system also offers highly accurate computation of various performance parameters, such as take-off distance required, power setting for the engines during the climb etc. Whereas the computer routinely incorporated in the flight management system up to now has tended too much towards the safety side, the new system allows much more accurate but at the same time safe calculations, making full use of the available aircraft performance. For example, a 777 can carry up to nine tonnes' extra payload on take-off from a wet runway. The Dutch airline KLM is the first customer to have already ordered the paperless cockpit.

All the changes and equipment options described above for the 777-300ER naturally posed special challenges for the production engineers. As in other divisions of Boeing, it was therefore necessary for management to pay particular attention to production processes and costs.

Jeremy Court is responsible for 777 final assembly. The Scottish engineer joined Boeing from car manufacturer Toyota, which is one of the industry leaders in production automation and flexible manufacture. Court explains that the continuously advancing final assembly line that will now been extended to the 777 is intended above all to increase the pressure on the workforce to remain on schedule. Up to now, it has often been only too easy to postpone dealing with production problems until the next day, with far-reaching consequences on planned production progress. As well as lowering production costs, however, the "moving production line” will also in future allow production of Boeing's flagship 777 to be flexibly raised to up to seven aircraft a month.

The first customer aircraft is scheduled for delivery in March 2004. 54 orders have already been received for the new long haul versions, the 777-300ER and the 777-200LR, from seven customers, Air France, All Nippon Airways, EVA Airways, GE Capital Aviation Services, ILFC, Japan Airlines and Pakistan International Airlines.

From page 28 of FLUG REVUE 1/2003

Last updated 5 December 2002

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