Dash ten Dreamliner

More seats, more cargo. Boeing’s 787-10 has received its certification and is due to enter service in May 2018. Mark Broadbent profiles the newest and largest Dreamliner

COMMERCIAL BOEING 787-10

At 224ft in length the 787-10 is 18ft longer than the 787-9 and 38ft longer than the 787-8, enabling it to carry up to 330 passengers and 40 LD-3 cargo containers. All photos Boeing unless stated

On January 19, 2018, Boeing received US Federal Aviation Administration (FAA) type certification for the third 787 Dreamliner variant, the 787-10.

The award of the amended type certificate followed the conclusion of a flight test and certification test programme that began in spring 2017. Other validating agencies, including the European Aviation Safety Agency (EASA), are expected to follow the FAA’s lead and certify the 787-10 before it enters service.

Brad Zaback, Vice President and General Manager of the 787, commented: “We are pleased to have met the rigorous standards set forth by the FAA and are eager to bring the aircraft to market for our valued customers. After years of design and testing, our team has proved the quality, safety and reliability of the newest member of the Dreamliner family and we look forward to seeing the aircraft in service later this year.”

Flying the 787-10 in 2017 and certifying it early in 2018 is in line with the development schedule Boeing laid out when it launched the variant at the 2013 Paris Air Show. Given the widely publicised issues it encountered bringing the 787-8 to market at the turn of the decade, Boeing will probably be relieved the 787-10’s certification and preparation for service has, like that of the 787-9, been achieved smoothly.

The initial customer 787-10 for the variant’s launch operator Singapore Airlines is due to be delivered during March 2018. On February 8, 2018, the airline revealed Singapore to Osaka, Japan will be the first scheduled destination for its 787-10, with services due to begin in May 2018. Before then, the 787-10 will be operated on selected flights to Bangkok and Kuala Lumpur to assist with crew training. A Singapore Airlines statement said the 787-10, “will be a key element of SIA’s overall growth strategy, enabling us to expand our network reach and strengthen our operations.” The carrier has placed orders for 49 787-10s so far.

Key characteristics

The third Dreamliner variant is the longest and highest-capacity 787 developed so far. Although it shares the same 197ft (60m) wingspan, 56ft (17m) height and 18ft 10in (5.74m) fuselage cross-section as the 787-8 and 787-9, at 224ft (68m) in length the 787- 10 is 18ft (5.4m) longer than the 206ft-long (63m) 787-9 and 38ft (11.5m) longer than the 186ft (57m) 787-8.

The extra length gives more capacity. The 787-10 will be able to carry 330 passengers in a standard two-class layout (32 in business class and 298 in economy) or up to a maximum of 440 passengers in an alleconomy layout, a 14% increase from the 787-9 and 36% more than the 787-8. The 787-10 has 6,200ft3 (175m3) volume for underfloor cargo, which Boeing’s latest Airplane Characteristics for Airport Planning document says provides space for 22 LD-3 containers (each sized at 158ft3/4.5m3) in the forward compartment and 18 LD-3s in the aft compartment.

The total of 40 LD-3s is four more than the 787-9 and 12 more than the 787-8. There is also 402ft3 (11.4m3) volume in the bulk cargo compartment. Total cargo capacity is 15% more than the 787-9 and 41% more than the 787-8.

In terms of payload/range performance, the 787-10 has the same maximum take-off weight as the 787-9, at 560,000lb (254,012kg) compared to the 553,000lb (250,836kg) of its 787-8 stablemate, and 6,430 nautical miles (11,910km) range in a two-class configuration compared to the 787-8’s typical 7,355 nautical miles (13,620km) capability and the 7,635 nautical miles (14,140km) of the 787-9.

Stretched fuselage

The 787-10 is a stretch of the 787-9. Wayne Tygert, the 787-10’s Chief Project Engineer until his recent move to become Vice-President Boeing Flight Test, told AIR International: “We’ve got an 18ft stretch, 10ft forward and 8ft aft. From a structural standpoint we added five frame bays forward [of the wing] and four frame bays aft. “We incorporated that through a local strengthening of the structure in areas that required it for loads increases because of the longer body.”

A key feature on the 787-10 that makes it different from the other Dreamliner variants is a semi-levered landing gear, which shifts the pivot point around which the aircraft rotates. Tygert said: “The additional actuator on the gear locks out so the aircraft can rotate about the rear wheel, rather than the midpoint of the landing gear truck,” as is the case on the other Dreamliners. “Essentially you then pivot on take-off around that aft wheel.”

Alongside the semi-levered gear, Boeing developed a new control law for the fly-bywire flight control system (FCS). As Tygert observed, “Any time you change an aircraft or lengthen it, you get slightly different handling characteristics,” which is why Boeing adjusted the FCS control laws so any handling differences with the parent models are minimised.

For the 787-10, engineers introduced a new control law that commands the elevators to generate nose-down pitch to adjust the fuselage’s attitude to prevent a tailstrike. This increases the clearance between the fuselage and the runway and therefore the safety margin for rotation and flare, enabling the 787-10 to have the longer fuselage.

Tygert stressed the work to achieve this change was straightforward: “It’s nowhere near the amount of work we do on a newly designed aircraft. We have the systems in place and we’re really tweaking the control laws to handle the changes we’ve made.”

The development of a semi-levered gear and an FCS control law to prevent tailstrikes is an example of the cross-pollination between

Building the 787-10

The 787-10 is assembled solely by Boeing South Carolina at North Charleston, with sections for the aircraft arriving from Europe, Asia and other factories in the United States.

Boeing 787 production takes place exclusively at North Charleston, South Carolina, at the site’s four million square feet (371,612m2) campus.

All Dreamliners are the result of a complex international supply chain involving Boeing and partners in North America, Europe and Asia. Section 41, the forward fuselage, including the nose and cockpit, is produced by Spirit AeroSystems in Wichita, Kansas. This company also supplies fixed and movable leading edges for the wing. Section 43 (mid-forward fuselage) is from Kawasaki Heavy Industries at Nagoya, Japan. From the same location comes the Subaru-fabricated Section 45 (wingbox), the wing (Mitsubishi Heavy Industries) and the wing fixed trailing edge and main landing gear wheel well (Kawasaki Heavy Industries).

Leonardo at Grottaglie, Italy, contributes Sections 44 and 46 (centre fuselage). Boeing Aerostructures Australia in Melbourne manufactures the movable wing trailing edge, Boeing’s Fabrication facilities in Salt Lake City, Utah or Frederickson, Washington produce the tailfin (although the rudder comes from the Chengfei Commercial Aircraft Company in China) and Boeing’s Fabrication plant in Winnipeg contribues the wing/body fairing and landing gear doors. The wingtips, flap support fairings and the Section 48 aft fuselage section come from Korea Aerospace at Busan, South Korea. The landing gear is manufactured by Safran Landing Systems in Toronto, Canada, the passenger doors are from Latécoère in Toulouse, France and the cargo access doors are from Saab in Linkoping, Sweden.

A pair of Rolls-Royce Trent 1000 TEN engines. This powerplant features several differences from earlier Trent 1000s, including a modulated air system, an increased use of composites, redesigned external systems, a new external gearbox and an updated engine control system. Rolls-Royce

A complex web of road, rail, sea and air transport brings all the parts for the 787-10 from the supplier factories to North Charleston. Boeing’s four in-house 747-400LCF Dreamlifter transport aircraft, bring the wings and mid-forward fuselage from Nagoya, the centrefuselage Sections 44 and 46 from Leonardo in Italy and Section 41 from Spirit in Wichita to South Carolina. Once all the parts are at North Charleston, Sections 43-46 are joined to centre-rear and aft fuselage Sections 47 and 48, which are produced at North Charleston by Boeing South Carolina. Before the mid and aft fuselage sections deliver to final assembly, they receive a topcoat and primary coat of paint to protect the composite fuselage from ultraviolet light before roll-out.

Final assembly of 787-10s follows the same process already established at North Charleston for 787-8s and 787-9s. Each aircraft advances through five different stages. At position 0, the wings are joined to the midbody before the forward and aft fuselage sections are joined to the midbody and the tail in position 1, where work also includes the installation of the floorboards, the landing gear and the hydraulic and electrical systems. In the next position, the team begins installing the passenger seats, and the aircraft is powered on and achieves weight on wheels. In position 3, the engine installation begins, along with the production tests and the cabin pressure tests. At position 4, the engine and interiors installations are finalised and electrical, hydraulic and mechanical systems testing is completed.

Each Dreamliner is then taken to North Charleston’s 396,208ft2 (37,790m2) paint facility where the aircraft receives its customer livery in one of two paint bays. Following painting, the 787-10 is weighed and its fuel system, pumps, valves, tanks, hardware and APU checked and its compass calibrated. All systems are tested, the engines are run and there are assessments of the tyres, shock struts and hydraulic fluids. In the cabin, technicians test the functionality of systems and the interior meets Federal Aviation Administration regulations. Then the aircraft moves to flight test and after customer acceptance and signing of paperwork the aircraft is delivered. designs in Boeing’s commercial aircraft. The company first developed these technologies in the early 2000s for the 777-300ER. Tygert observed: “As we make derivatives all our aircraft benefit from learnings we’ve made in the past. The tailstrike protection on the 777 was the basis for the [787-10] system and we learned through the work we were doing on the 777X how to improve it.”

Engines

Customers can choose either General Electric (GE) GEnx-1B or Rolls-Royce Trent 1000 TEN engines for the 787-10. Both engine choices provide up to 76,000lb (338kN) of take-off thrust.

The two suppliers have upgraded their baseline GEnx-1B and Trent 1000 engines over time to provide greater performance. General Electric has introduced incremental Performance Improvement Packages to enhance the GEnx-1B and Rolls-Royce introduced Package B and Package C improvements for the Trent 1000.

However, Rolls-Royce describes the Trent 1000 TEN (which stands for Thrust, Efficiency and New technology) for the 787-10 as a “step change” in the Trent 1000’s design, leveraging technologies the company developed for the Trent XWB engines it designed for the A350.

Specifically, Rolls-Royce says the Trent 1000 TEN has a new compressor system that employs scaled-down intermediate pressure and high-pressure (HP) compressors first developed for the Trent XWB-84 powering the A350-900, while the HP turbine architecture is shared with that of the Trent XWB-97 developed for the A350-1000.

Other differences between the Trent 1000 TEN and the Trent 1000 Package C engines are a modulated air system, an increased use of composites, redesigned external systems, a new external gearbox and an updated engine control system using what Rolls-Royce describes as “new-generation advanced processor technology”.

The Trent 1000 TEN is designed to power all 787 variants, not just the 787-10. The engine received its EASA certification in August 2017 entered service on the 787-9 in November 2017.

Extensive commonality

Despite the stretched fuselage, semi-levered gear and the FCS changes, Tygert emphasised to AIR International there are minimal structural and systems differences between the 787-10 and the other Dreamliner variants.

He said: “We’ve not added anything new or novel and we leaned off the base model as much as we could. Our goal was to maintain as much commonality and make it as efficient as we could from an operator’s perspective in maintaining the aircraft, keeping differences to a minimum, so they see minimal disruption to their maintenance and procedures.”

Boeing says there is more than 95% commonality between the ‘Dash Ten’ and the other Dreamliners. The 787-10 has similar main structures, components and systems to the other family members.

Like the other variants, nearly 50% of the 787’s airframe by weight is made up of advanced carbon fibre composites with the fuselage, tail and wing all featuring these materials. The balance is made up of 20% aluminium, 15% titanium, 10% steel and 5% other materials.

There are two kinds of carbon fibre composites: carbon laminates and carbon sandwich structures. Carbon laminates, used in the fuselage, vertical and horizontal stabilisers, wing covers and wing leading edges, are made by forming carbon fibre infused with a resin into a tape built up in layers to create a structure for curing. Carbon sandwich structures are found in the vertical and horizontal stabilisers and wings, and are made by attaching two thin but stiff skins to a lightweight, thick core.

Three 787-10s were used in certification testing, including N528ZC (c/n 60256), pictured here during take-off performance flights.

As well as composites, another key aspect of the 787 is its electrical architecture and power distribution system. In a traditional architecture, HP bleed air diverted from the engines powers key functions, including the auxiliary power unit (APU) starter, engine starter and hydraulics, as well as wing antiice protection and the environment control system (ECS) for the cabin.

By comparison, on the 787 these functions are powered by an electrical system. Generators on each engine and the APU directly connected to the engine gearboxes provide power, with power feeders running to an aft electrical/electronics bay and remote power distribution units.

Tygert emphasised to AIR International the 787-10’s larger size did not create an impact on this architecture. He said: “There were no major changes at all in the system. It’s just tuning it up to meet the power demands. You increase the length in the wires, you increase the necessary areas to handle the stretch.”

To give an example, the 787-10’s higher seat count meant Boeing needed to increase the cabin ECS and fire suppression systems’ capacity. Boeing uprated the existing architecture of electrically-actuated HP compressors, low-pressure air conditioning packs and the associated wiring to, as Tygert put it, “have the system capacity to handle the stretch”.

Testing

The initial 787-10, N528ZC (c/n 60256), rolled out at Boeing’s North Charleston plant in South Carolina in January 2017 and undertook its first flight on March 31, 2017. During the remainder of the year, N528ZC and two other flight test aircraft (N548ZC, c/n 40929 and N565ZC, c/n 60257) flew and joined the flight and certification testing of the variant, during which the three jets accumulated about 900 test hours.

Tygert told AIR International more about the testing undertaken to assess the aircraft’s handling, systems and overall performance and ensure the 787-10 met the manufacturer’s internal requirements and, above all, the standards laid out in the FAA’s Federal Aviation Regulations Part 25 (FAR-25) and EASA regulations for large turbojet aircraft.

He said: “When it’s a derivative aircraft like this one, we tend to approach [testing] from an incremental standpoint [looking at] changes to the aircraft, how those are integrated and how they affect the regulations and requirements. We structure our test programme accordingly. On the 787-10, some of those were the typical requirements you find on a derivative-model aircraft, because you’ve essentially affected the handling characteristics.

“We start out with envelope expansion testing where we prove the aircraft is performing and acting the way we intended it to from the design. We go into general airworthiness [and] flutter testing to show the lengthened fuselage and envelope performance meet the requirements.

“We do typical stability and control and handling characteristics, autoflight and then general flight control system testing to ensure the changes maintain the control laws and check they’re performing as intended.”

Singapore Airlines has ordered 49 Boeing 787- 10s and is due to receive its first example in March.

A major priority was assessing the longer fuselage’s impact on the aircraft’s handling and, Tygert said, “ensuring it didn’t impact in any way on the ability of the pilots to control the aircraft close to the ground and during landing”.

Key to proving this performance were the take-off performance tests carried out at Edwards Air Force Base in California and the crosswind landing trials undertaken at Gander International Airport in Canada. Tygert said: “We needed to prove the takeoff characteristics were what we believed them to be. We also did tests where we looked at the aircraft as it’s getting close to the ground.”

These two locations were chosen because they have long runways, the ability to handle Boeing testing and, in Gander’s case, a suitable runway direction relative to the prevailing winds for carrying out crosswind tests.

Alongside the certification work, Boeing also used the 787-10 testing to assess the impact on operations and maintenance of of the differences in the aircraft’s structure and systems. Tygert said: “We validated them during our test programme and took the opportunity to operate the aircraft like an airline would to find out if there were any areas that might surprise us. We didn’t find any, but we were trying our best to ensure the 787-10 is ready for service. [Airlines] will be able to operate the 787-10 just like they will a 787-9”

Fitting into the family

As noted, the 787-10 won’t be able to fly quite as far as its Dreamliner siblings. Its listed range is also 1,100 nautical miles (2,037km) less than the 8,100 nautical miles (15,000km) range capability Airbus quotes on its website for the A350-900.

Boeing noted range capability depends on the rule sets used. The company told AIR International its analysis is an A350-900 with the same rule-set as a 787-10 will fly 7,120 nautical miles (13,186km), meaning the 787- 10 with its 6,430 nautical miles (11,910km) capability would have only 690 nautical miles (1,278km) less range than the A350-900.

However, capacity rather than range is the point of the 787-10. Boeing’s calculation is the 787-10’s capacity gives it an edge in economics. The 787-10 is designed to provide a more fuel-efficient replacement for legacy Boeing 777-200ERs and Airbus A330-300s and A340-300s used on network airlines’ most popular trunk routes, reducing per-seat operating costs and allowing airlines to fly such services more efficiently.

On launching the aircraft in 2013, Boeing made the bold prediction the 787-10 would be, “the most fuel-efficient medium and longhaul jet ever developed”. The company claims it will have an 8% lower cash operating cost and 9% lower fuel burn than the 325-seat A350-900, and that it will burn 25% less fuel than legacy 777-200ERs and A330-300s. The 787-10’s seating and revenue cargocarrying capacity is designed to offer airlines a new-generation platform to raise frequencies on their bread-and-butter services – for example, the routes between Europe and North America, between Europe and Asia and within Asia, where the need for an efficient high-capacity hauler is most pressing.

The aircraft is designed to fit into the Dreamliner family by offering scale. Broadly speaking, the Dreamliner family concept has the 787-8 and 787-9 optimised for network development, with the 787-10’s ability to carry more passengers and underfloor cargo enabling airlines to add capacity if required.

Orders outlook

When the 787-10 was launched Steven Udvar- Hazy, the Chief Executive of the Air Lease Corporation, which has so far ordered 25 787-10s, commended the variant’s “ideal size, capabilities and economical operating costs”.

Despite the praise, however, 787-10s have sold slowly. Most of the orders in the backlog were placed on the aircraft’s 2013 launch, although EVA Air of Taiwan ordered 24 in November 2015 and Singapore Airlines ordered a further 19 (along with 20 777Xs) in March 2017.

The purchase commitment from Emirates announced at the Dubai Air Show in November 2017 for up to 40 examples is yet to be firmed and added to the official orders backlog. Even if and when these aircraft join the backlog, Boeing will still have only sold a couple of hundred examples.

The first 787-10 was rolled out in January 2017 and flew two months later; the 900-hour flight and certification test programme was concluded on schedule.
Orders for Boeing 787-10s have been sluggish, although the backlog still contains large commitments from carriers such as Singapore Airlines and Etihad Airways.

Wider factors are likely influencing the orders situation. Sales of all the newgeneration, more efficient widebody products, either Boeing or Airbus (and whether they are clean-sheet designs like 787s and A350s or new variants of existing models like 777Xs and A330neos) have slowed in the last couple of years.

This is partly because already-bulging order backlogs affect availability (for example, should Emirates finalise its 787-10 orders it won’t receive its first aircraft until 2022), which could impact airlines’ desire to order.

Also, lower fuel prices since 2014 have arguably quelled the market’s demand to introduce newer and more fuel-efficient types.

Regardless, Boeing predicts a healthy future for the 787-10. In its latest long-term Current Market Outlook to 2036, released in June 2017, the company forecast a need for 5,050 new small widebodies (787-8s and 787-9s) and 3,160 new medium widebodies (including 787-10s) from now to 2036. (Boeing defines the 787-8 and the 787-9 as ‘small widebodies’ in the 200-340 seats category and the 787-10 as a ‘medium widebody’ in the 340-450 seats category with the 777 and 777X.) Just like Airbus with its A330/A350 mix, Boeing aims to cover the full spectrum of the widebody aircraft market’s requirements and drive sales by having the 787, 777 and 777X complement each other in seating, range, payload and roles – the Dreamliners at the lower end of the scale, the Triple Sevens at the top – and offering commonality in systems and training within each family and between families.

Many airlines have embraced the concept. All Nippon Airways (ANA), British Airways (BA), Etihad Airways, EVA Air and Singapore Airlines have all ordered 787-10s to complement their existing 777s and, in the cases of ANA, BA and Etihad, their other Dreamliners. With the 787-10 set for its service debut, operators will get the chance to assess the promises about the aircraft in everyday service. If those promises stand up, maybe the confident predictions about future sales will come good and back up Udvar-Hazy’s bold prediction, made on the aircraft’s launch in 2013, that the 787-10 could become one of the best-selling commercial jetliners “for decades ahead”. AI