Boeing 787 (partie 1)

Boeing's first test-flight 787 Dreamliner made an unscheduled landing at Moses Lake, Wash., Friday after test pilots lost thrust in one engine.

"It was an opportunity to really see the best of Boeing kick into gear," Randy Tinseth, vice president of marketing for Boeing Commercial Airplanes, wrote on his blog Sunday.


Teaming with Rolls-Royce, we determined that the issue had to do with a pressure-sensing component within the engine.

We located replacement parts and then got the parts and the right crew to Moses Lake -- beginning the maintenance activity on Saturday. Later that day, we ran the engines to confirm that the replacement had been done correctly and that there were no anomalous readings.

So, Sunday morning, we flew home. The airplane is going through the maintenance and pre-flight work that would have been done had it arrived back at Boeing Field on Friday evening.

The plane will "soon" return to testing for flutter -- natural vibration that can amplify and damage the jet, Tinseth wrote.

"It's a great tribute to the team that they completed the analysis, maintenance activity and testing in such short order. This is what happens during flight testing -- and our plan accommodates such events," he wrote. "We deal with issues and we keep going."

Mixed news for Boeing first thing Monday as the 747-8 returns to flight, while the 787 team continue to troubleshoot engine issues which have forced the postponement of flutter tests.
First flight of ZA004 – the next 787 scheduled to join the test program - was also scheduled to take place later today but as of late Sunday, there appeared to be some fresh uncertainty as to whether this would in fact proceed.

The 747-8 is scheduled to fly to Moses Lake where it will be temporarily based while conducting initial airworthiness tests before moving south to Palmdale, Calif., for the bulk of the certification effort. Boeing originally filed a flight plan calling for a 7 am departure from Everett, but later on Sunday revised the expected flight time to sometime after 9 am.

The issues with the 787 cropped up on ZA001 during the fifth day of flutter tests on Friday. Writing in his blog, Boeing Commercial marketing vice president Randy Tinseth says during the flight the crew experienced “an uncommanded loss of thrust in the one of the engines,” and landed at Grant County International airport (AKA Moses Lake). “Teaming with Rolls-Royce, we determined that the issue had to do with a pressure-sensing component within the engine. We located replacement parts and then got the parts and the right crew to Moses Lake - beginning the maintenance activity on Saturday. Later that day, we ran the engines to confirm that the replacement had been done correctly and that there were no anomalous readings.”

The aircraft ferried back to Boeing Field where, according to All Things 787, some maintenance work was observed being undertaken during Sunday on the right Trent 1000. This work appears to be taking longer to conclude than hoped as late Sunday evening Boeing took the decision to slide the 6th flutter test flight (originally re-scheduled to Monday), and to conduct further ground tests later today.




Trent 1000 on ZA003 as viewed from the cabin (Guy Norris)

For ZA004 the situation remained uncertain going into Sunday night, the test crew earlier that day having successfully cleared the aircraft for first flight later today. As I write this it is not yet known if the engine sensor tests on ZA001 may have forced a precautionary delay to the first flight of ZA004. The second aircraft, ZA002, is meanwhile due to undertake taxi tests on Monday, some of which are believed to be associated with nose gear steering evaluations.

787 and 747-8 updates
Posted by Guy Norris at 2/22/2010 7:36 PM CST

With engine sensor tests now apparently completed to its satisfaction following this weekend’s hiatus, Boeing is set to resume 787 flight tests tomorrow – possibly to include ZA004 for the first time. The news comes as the first 747-8F, RC501 conducts its second flight – taking off from Paine Field at 4.10 pm this afternoon, en-route to its temporary base at Moses Lake. The aircraft is still airborne as I write this blog, and was expected to be flying in company with a Boeing T-38 chase aircraft for at least the second half of today’s sortie.

Boeing isn’t saying too much yet about the engine pressure sensor incident which forced ZA001 to stay at Moses Lake for most the weekend, but the fact the aircraft is now scheduled to resume flutter testing tomorrow appears to indicate the issue is basically behind it.

ZA002 is scheduled to continue stability and control tests tomorrow with a focus on longitudinal flight control characteristics. A slew of ground tests are also in work while ZA002 is not flying at the moment including tests of the tank inerting system together with associated temperature measurements of the fuel, and – possibly later this week – some ground work in readiness for flight evaluations of the trailing edge variable camber system (TEVC).

The TEVC cleverly articulates the trailing edge of the flaps in various cruise conditions to help reduce drag. The system was originally designed to work by deflecting the flap by very small (0.5 deg) increments for a total travel of around 3 deg (1.5 deg up or down), though the final version developed for flight tests may vary slightly. Either way, the TEVC represents the first steps taken by Boeing, or anyone else for that matter as far as I know, towards a practical application on a commercial jet of a ‘morphing wing’ and is another of the many technologies which the company rolled into the 787 in search of significant fuel-burn savings.




More than just a pretty picture? 787's soon-to-be-tested 'morphing' trailing edge. (Guy Norris)

The first flight of ZA004 is meanwhile tentatively re-set for tomorrow having been put back from today for unknown reasons.

I just checked and according to Flightaware, RC501 is still boring holes through the skies of central Washington State. More updates to follow.

UPDATE: Boeing confirms the engine pressure sensor glitch was a hardware problem associated with one specific unit, and was not an issue with the electronic engine control unit or any of the control software. It also says that the sensors on the other Trent 1000s in the flight test fleet, including those on ZA002 and ZA004 were checked as a precaution - hence the hold to first flight of ZA004.
RC501 meanwhile arrived safely at Moses Lake at 5.45 pm according to Flightaware.

First flight of interiors-fitted 787 slides to March
By [url=mailto://]Jon Ostrower[/url]









First flight of Boeing's third flight test aircraft has moved into March, citing a pre-fitting of flight test instrumentation that the company believes will help the aircraft fly more often.
"We've got some open work to complete on the airplane and have decided to accelerate the installation of some flight test equipment that we had originally planned to install after first flight," says Boeing.
The aircraft, powered by two Rolls-Royce Trent 1000 engines, will be used to test the cabin environment of the 787 and is fitted with a partial interior along with side walls, lighting, seating, galley equipment, crew rest areas and overhead bins.
Beyond the cabin testing, the aircraft will also participate in extended twin engine operations testing, systems functionality and reliability tests, as well as electromagnetic effects (EME) and high intensity radio frequency (HIRF) testing related to lightning strike protection.
The aircraft will also validate design changes to the environmental control systems, say programme sources.
Boeing sees the slide of the aircraft's first flight - designated ZA003 - as an overall benefit to the programme and calls the move a "typical adjustment" and a "smart move overall", despite the aggressive 3,100hr flight test schedule that the company is undertaking for the 787.
The airframer says it is "taking some extra time to get in the air but we will be able to fly more often sooner in its flight test schedule, which will be an overall benefit to the program".
ZA003 will be the fourth 787 to fly after ZA004 made its maiden flight on 24 February.
ZA005 and ZA006, both powered by General Electric GEnx-1B engines are expected to make first flight before the end of April.
First delivery to Japan's All Nippon Airways is expected in the fourth quarter.
Boeing holds 876 orders from 57 customers for the 787.

With June set for firming the configuration of the 787-9, Boeing is taking major strides to incorporate what it has learned on testing the 787-8 in the air and on the ground to optimize the aircraft. The first 787-9 was initially intended to be Airplane 88, which later became Airplane 109 and now stands at Airplane 139 (ZB001). The first 787-9 will be delivered to Air New Zealand at the end of 2013.


The task ahead is an engineer's dream (or nightmare): Stretch an airframe 20ft, add about 40 seats, make it fly 8,000 to 8,500 nm - farther than its predecessor - all while keeping the wing the same span, and having having 100gal less fuel to work with, all while removing potentially thousands of pounds of excess weight from the original -8 design.


The stretch, which comes entirely in two 120in, 5-frame additions to the 43 section (built by Kawasaki) and the 46 section (built by Alenia), will come through the production system through center fuselage integration at Boeing Charleston, which was sized for the larger aircraft.


The 787-8 and -9 wing has been a subject of great debate inside Boeing for years now, as the -9 wing grew to three times to 207ft 11in, then came back to a common planform as the -8 with a 197ft 3in wingspan last Spring as early static tests and the -18 wing break test showed the strength of the wing box (side-of-body not withstanding). Additionally, the reduced span was set set to save an estimated 4000lbs, which would have cost more range than the increase in aerodynamic efficiency would have yielded.


With static airframe ( ZY997) testing heading toward ultimate load, the design of the side-of-body reinforcement will be put through its paces, allowing Boeing to resize the fittings if necessary, which have added a notable amount of weight to the aircraft to ensure their strength, say those close to the aircraft. Additionally, the flight loads survey that will be conducted by ZA004 will help calibrate finite element methods used to size the 787-9.


Program engineers also say that the one-piece barrel structures have survived loads far beyond expectations, and well in excess of certification requirements. While a marketing victory of sorts, those same engineers see that kind of strength in the -8 as a sign of an over-designed structure. The more Boeing learns about the -8 structure, the more optimization can take place for the -9.


Major changes - many obstructed from public view - will be coming on the systems level for -9. The Airbus Dossier of October 2008 - and its conclusion - provide some indication of the changes coming, but more than a year later, program sources say that the guts of the -9 are "significantly different" in some areas to the -8. One known area is an increase in the APU power output from 225 KVA on the -8 to 250 KVA on the -9, along with a revised cargo environmental control system.


The landing gear, for example will be larger than that of the -8 with larger main trucks and wheels, tires and brakes. As a result, the wheel well pressure deck will be raised and the structural architecture revised to accommodate the larger landing gear.


For Rolls-Royce, the technology developed for the Trent 1000 Package B engines set to be tested first on ZA004 later this year, will be a big driver for the entry into service fuel burn expectations of the 787. Even beyond that, Rolls-Royce is aiming to have an additional 1% improvement even beyond the Package B EIS spec, not to mention whatever Trent XWB designs are fed back into the 1000.


Not to mention, we'll finally find out what happened to that missing window!

Nearly three months into its planned 8.5 month-long flight test programme, the Boeing 787 is progressing well, says the head of the company’s commercial aircraft unit, but acknowledges that some schedule margin has already been used ramping up the flight test fleet.

Jim Albaugh, president and CEO of Boeing Commercial Airplanes, calls the aircraft "solid as a rock" as he recounted the milestones accomplished by the three flying 787 flight test aircraft.

Albaugh’s remarks came at the J.P. Morgan Aviation, Transportation & Defense Conference in New York City on 9 March.

Albaugh says the 787 is about 40% through flutter testing, which began on 14 February, and adds that about 100 stall tests have been completed, along with several engine-out tests and autolands.


Jon Ostrower



Additionally, ZA001, Boeing’s first 787 flight test aircraft, reached M.97 in a dive during a flutter test, and reached an altitude of 43,000ft while maintaining a cabin pressurisation of 6,000ft (1,830m), a key feature of the 787’s touted improved passenger experience.

"The airplane performance is very, very clean so far," says Albaugh.

To date, the three aircraft have accumulated about 260h of flight testing. The fourth, ZA003, is expected to join the flight test programme on 21 March, he adds.

Type Inspection Authorisation (TIA), which will formally kick off the FAA’s inclusion in the 787 flight test certification campaign, is expected to occur by the end of March, says Albaugh.

Albaugh’s acknowledges that "we did burn a little bit" of the built-in flight test "contingency" margin, which programme sources say had TIA initially scheduled for late-February.

During pre-first flight test briefings with the media held in April 2009, Boeing said it planned for TIA to take place about two months after first flight, which occurred on 15 December 2009.

Albaugh did not specify how much of that contingency planning margin had been used already, and says "We’re working very hard to improve the efficiency of the test programme, which means do more test points per flight. And we’re also trying to improve the turnaround of the airplane, so we can get more hours in the air with the six airplanes that we’re going to have."

Albaugh says the slower than planned start to the flight test programme was attributable to a steep learning curve and a longer aircraft turnaround time, limiting the number of daily flight test hours.

While Boeing initially planned for an 8.5-month flight test programme to certify the 787, the company expanded its planning, giving itself from fourth quarter 2009 to fourth quarter 2010 to conduct the six-aircraft 3,100h flight test campaign.

Albaugh says the schedule has "a month or month and a half of contingency in the flight test programme against the entry and the service date later this fall or early next winter. We have contingency, and I think it’s adequate. We’ve got a lot of levers that we can pull [improving] efficiency, getting airplanes in the air."

In an effort to rapidly accelerate the pace of certification, Boeing significantly changed its methodology for the 787 flight test programme, assigning teams to look holistically at the test fleet rather than individual test aircraft, as well as utilising downtime at night between flights for maintenance and preparation for the following test day to leverage all 24h in the day.

As the fourth, fifth and six flight test aircraft come online, Albaugh says the added length of the Pacific Northwestern days, providing 16h of daylight in June, will help the rapid accumulation of flight test hours.

"We’ll be flying the wings off those airplanes," says Albaugh.

Boeing set for ultimate 787 Dreamliner wing test on Sunday


787 Dreamliner static airframe during wing-bend test to 105 percent of service load on Nov. 30, 2009. (Boeing) Click to enlarge



Boeing intends to perform the ultimate wing test on the 787 Dreamliner on Sunday, program spokeswoman Lori Gunter confirmed Tuesday.
The test, which would take the wing of Boeing's 787 static-test airframe to 150 percent of the load it is expected to ever endure in service, is a key milestone for the program. It was a test at just above the 100 percent service load last year that uncovered a problem where the wing and fuselage meet, delaying first flight.
Boeing bent the wing to 105 percent of the service load Nov. 30, validating a fix to the side-of-body issue and clearing the 787 for flight testing.
FlightBlogger first reported Tuesday that the ultimate wing test was scheduled for Sunday. That, as with all tests, is subject to change, Gunter noted.

Boeing completes 787 ultimate-load wing flex test

Boeing has completed the ultimate load wing up-bending test on the 787
static test unit, ZY997, at its facility in Everett, Washington.
The airframer says that it applied loads to replicate 150% of the
most extreme forces the airplane could experience while in service,
resulting in the wings being flexed upward by approximately 25ft (7.6m)
during the test. In order to achieve certification, the US FAA requires
aircraft structure to withstand 150% of limit loading for 3s.
The company says that during every second of the over two-hour test,
thousands of data points were collected to monitor the performance of
the wing.



^Boeing
Initial results appear to be positive, says Boeing. However, it adds
that it would take several weeks to work through the data, and conduct
more extensive analysis and reviews, before calling the test a success.
The data collected will also continue to confirm the strength of the
structural reinforcement installed on the 787's side-of-body, which
forced Boeing to announce an additional six-month slip in the programme
in June 2009 while it devised a solution.
"The test program has been more robust than any conducted on a Boeing
commercial jetliner," says Scott Fancher, vice-president and general
manager of the 787 program, Boeing Commercial Airplanes. "We are looking
forward to the technical teams report on the details of the test
results."
The first delivery of the 787, which is delayed by over two years, to
launch customer All Nippon Airways (ANA) is scheduled for the fourth
quarter of 2010.

The 787 wing test: "That will be all"
Posted by Michael Mecham at 3/30/2010 8:00 AM CDT


Boeing

Analysis of Sunday’s ultimate wing test of the 787 on the ZY997 static test rig is still underway, so the official results are not yet in.

But the initial word is positive, the company says.

The airplane’s wings have a span of 197 feet. They are so flexible in flight that their racked wingtips easily rise above the top of the fuselage.

Still, seeing them flex 25 feet above their normal at-rest position is impressive, as this image shows. At that point, the wings were experiencing loads equal to 150% of the maximum they are expected to endure during commercial operations.

In Sunday’s test, apparently the wings were taken just to that point – a certification requirement – and no further.

Use of composite airframes is not new in airplanes. But the 787 is the largest one ever built with them. Former Boeing Vice President Walt Gillette, who played a big role in their introduction and that of the many other technology advances on the 787, always downplayed the drama of their use. The main point, he would say, is that composites are lighter, can be manufactured faster and are less susceptible to corrosion than aluminum alloys.

Boeing’s use of composites is “evolutionary, not revolutionary,” Gillette said.

Still, in the early days of the program, 787 managers said the design team was curious just how strong the new airplane’s wings really are.

Of course, the way to find out is to see how much strain they will take before breaking, which is what Boeing did on the 777, the first airplane it designed using computer modeling.

But in recent times, talk of maybe testing the 787’s wings until they break has gone away, perhaps because Boeing has been battling production delays, including a six-month setback when the airplane’s wing-to-body join needed strengthening.

Now the focus is entirely on execution, completing flight testing successfully, gaining certification and delivering that first airplane to All Nippon Airways, hopefully late this year.

Another possible reason for not testing more is the need to dismantle the ZY997 test rig within the next two months to make room for other manufacturing activities.

Asked Monday if there was any chance the designers’ curiosity might be satisfied with a wing destruction test, a Boeing public affairs official shot back a quick email reply.

“No.”

Boeing's proposed 787-10 stretch may be back on the radar as the 787 and 747-8 programs are retiring risk, according to a new report from New York-based Bernstein Research.

The report, released yesterday, also highlights concerns that the 787 may be falling behind on its flight test hr., although Boeing remains within the margin to enable the first three aircraft to be delivered to ANA by year end.

Following meetings with Boeing management, Bernstein said the manufacturer is "more confident about potential 787 weight reduction, which has made the second stretch airplane, the 787-10, again a possibility." The research group noted that it "does not know specifically where the 787 stands on weight" but that Boeing expressed confidence that later airplanes will meet performance requirements.

"One measure of progress on the 787's weight is that management is again looking at the possibility of a second stretch, i.e., a 787-10," Bernstein stated. It sees the derivative, along with a 777 rework, as part of the manufacturer's response to the A350-1000.

It is generally accepted that the 787-8 was overdesigned for a high margin of error on structure and lightning protection. The view at Boeing "is that there should be substantial potential to take out structural weight," Bernstein said. Airlines originally were pushing for a 50-seat stretch over the 787-9 with identical 8,500-nm. range, while Boeing wanted a straight payload/range trade with a 7,000-nm. range (ATWOnline, July 10, 2007).

The Bernstein report raised concerns about rework given that 30 787s and 15 747-8s will be complete before certification programs are concluded. It noted that "the potential for significant rework still exists on both programs. The discovery last week in 747-8 test flight of buffeting due to airflow over the landing gear door is an example." That problem, however, is regarded as minor.

It said the overall risk of substantial rework on the 787 has come down significantly after successful flutter/stability control flight tests and structural static wing tests (ATWOnline, March 30).


by Geoffrey Thomas

Boeing is pressing forward with the 787 flight test program and believes first delivery to ANA by the end of November is feasible.

The manufacturer expects to obtain Type Inspection Authorization for the 787 this week after passing flutter and structural wing bending tests. TIA will formally kick off the FAA certification process.

Meanwhile, ZA005, the fifth flight test aircraft and the first powered by GEnx-1B engines, is on the flight line at Everett and is being prepared for its first flight, currently scheduled for May 8. The final flight test Dreamliner, ZA006, is expected to be in the air by June 4 and now is in building 40-24 adjacent to the 777 production line.

Boeing is conducting up to 90 hr. of flight testing weekly to support the delivery goal. By the end of November it plans to have built 30 delivery-standard 787s.

Visiting the 787 production line in Everett last week, ATWOnline saw ship LN17 (the first for Royal Air Maroc) as well as LN18 (for ANA) and LN19 (the second RAM aircraft). LN20, the first for Japan Airlines and also the first "weight-optimized" 787, started final assembly in late March.