Boeing 787 (partie 1)

Boeing and Rolls-Royce are investigating the causes of a Trent 1000 engine surge that has grounded flight tests of the first Boeing 787 at Roswell, N.M.

Boeing also is assessing whether the latest engine incident may cause further slips in the hard-pressed 787 delivery schedule. The failure occurred on Sept. 10 during ground tests of the first 787, ZA001, which was at Roswell for Block 1 rejected takeoff work, plus brake demonstration certification and stability and control tests. The aircraft, which has been based at Edwards AFB, Calif., for most of August for runway performance work, was on its second visit to Roswell, having earlier been there for wet runway testing.

Boeing says ZA001 “experienced an engine surge during testing on Friday afternoon. The event occurred prior to takeoff and the crew completed the appropriate maneuvers. Back-up systems performed as designed, and the crew and the aircraft were safe throughout the event.”

The manufacturer adds that it is working with Rolls-Royce to “investigate the event and understand the root cause.” However it says early results, based on initial input from the “team on the ground in Roswell, indicate that this engine failure is not related to the test event in Derby.”

This earlier event occurred on Aug. 2 on a Package A initial delivery configuration engine running on Rolls-Royce’s Bed 58 indoor test site in Derby in the U.K. The engine suffered an uncontained, intermediate pressure, turbine-related failure due to what Rolls describes as tests in an “inappropriate operating regime.” The disruption caused by the engine problem, added to ongoing inspection issues with the horizontal stabilizer, forced Boeing to push back first 787 deliveries to launch customer All Nippon Airways to February 2011, rather than the end of this year, as originally planned.

Of the latest incident, Boeing says, “It’s too early to determine if there will be any impact to schedule. We need to let the team do the necessary work to understand what happened and what caused it.” It adds, however, that “this appears to be an isolated incident, though a full study will be made to ensure thorough understanding.”

Boeing says that a flight test engine is available and that “the team is installing it in New Mexico and will resume testing soon.” Initial engine check-out flight tests are expected to take place as early as Sept. 17. If the engine tests are satisfactory, the ZA001 test team expects to resume brake and stability and control tests the following day.

Boeing's two week hold in 787 shipments has overshadowed an even longer period of non-movement in the final assembly line, as the company works to address lingering horizontal stabilizers issues.

Driving the latest hold, the third this year, is a shifted delivery schedule of the Alenia Aeronautica-built 787 horizontal stabilizer and the need to deliver a shipset free of workmanship issues, first disclosed in June, that would need time consuming rework at Boeing's Everett, Washington final assembly facility, says Boeing.

Yet, as Boeing disclosed the two two-week hold in delivery, structural sections had already been accumulating in the back of the factory as the assembly line has not advanced since early October for Airplane 28, and the line is not set to pulse again until early November and could stretch to the middle of the month, according to those working on the program.

As recently as August at the time of the last delay announcement, Boeing Commercial Airplanes CEO Jim Albaugh expressed confidence in the recovery plan, saying "horizontal stabilizer 27 and on we're not too worried about, we've got that one pretty well overwhelmed."

Though horizontal stabilizers 28 and 29 will still require inspection and potentially significant rework. Boeing now expects the first "clean" stabilizer free of workmanship issues to be delivered from Italy starting with Airplane 30.


However, even as Boeing eliminates the headache of having to rework stabilizers 30 and beyond in Everett, the airframer's machinists and engineers must inspect, diagnose and complete rework on the 23 production aircraft already assembled before each one can be handed over to a customer.


The US airframer has found itself in a complicated dance of horizontal stabilizers inside the factory as they are reworked, while Boeing is making provisions to support the rework required to fix the Alenia workmanship issues on the already assembled airframes.


"Detailed inspections [of the horizontal stabilizers] are continuing at the same time we are building," says Boeing.

The four-position 787 line is stocked with Airplanes 25 (Air India), 26 (Air India), 27 (JAL) and 28 (Air India) at assembly positions, while a near-complete complement of parts for Airplane 29 waits in pieces at the rear of the factory along with the wings for Airplane 30. Notably missing from both planes are the horizontal stabilizers for Airplanes 29 and 30, two shipsets behind.

Another program source expects the horizontal stabilizer for Airplane 29 to arrive in the coming days, with number 30 to arrive in Everett once the delivery hold is lifted early next month. The remaining parts for Airplane 30, the forward and aft fuselage, are being stored in a Dreamlifter away from the elements.

Airplanes 25, 27 and 28 all have horizontal stabilizers, though each is heavily stripped down while being reworked. Airplane 26 remains without a horizontal stabilizer as the line move trumped the installation, which occurred while it was being reworked.

After Airplane 26 advanced to position two, Airplane 27 was fitted with the horizontal stabilizer intended for Airplane 26 after preliminary rework was complete, while the airplane was in position one inside the factory. The stabilizer originally meant for Airplane 27 is now installed on Airplane 28.

The horizontal stabilizer for Airplane 29, when it arrives from Italy, is likely to be installed on Airplane 26 before it leaves the factory prior to loading of Airplane 30 into final body join.


Boeing's first delivery hold, announced in late April, stretched into early June, with a second lasting a total of 28 days split between 10 manufacturing days preceding delivery of Airplane 26, and another covering 18 manufacturing days following the arrival of the wings of Airplane 28.

Horizontal stabilizer 28 remains in the horizontal stabilizer integration (HSI) tool on the factory floor, and will likely be loaded on Airplane 29 once the line advances forward. Boeing will re-sync the horizontal stabilizers beginning again with Airplane 30 when deliveries resume again.

The last time Boeing's line advanced was on October 3, and the shifting of the 787 line forward was initially scheduled for October 13, followed by another move on October 25, though neither took place opting to hold the line in place on both occasions. The company says the line won't move again until November 4 at the earliest, despite a complete shipset for Airplane 29, which now includes Airplane 28's stabilizer, in the factory.

Though one source in program manufacturing indicates that another line hold could be instituted, pushing the next forward move, and the start of assembly of the 29th 787, to mid-November.

As it anticipates the need to conduct rework on the existing production horizontal stabilizers out of the normal assembly sequence, Boeing has added a new laydown position in the rear of the factory to rework the stabilizers before moving to the HSI tool for integration.

In that August interview, Albaugh added the company would be able to perform any required rework without removing the horizontal stabilizer, which remains true. However, with repairs involving invasive rework, crews may have to remove the tail cone and vertical tail plane of the aircraft to gain access the the stabilizer.

Boeing has developed a new tool to rework the horizontal stabilizers that accommodates a holding slot for the KAL-ASD built Section 48 aft tail cone and vertical stabilizer and a work area to provide unfettered access to the horizontal stabilizer.

For the production-airframe horizontal stabilizers, most of which have been installed, program sources say Boeing is now inspecting the shims, some found to have gaps as large as .1 to .2in, on 600 areas on the fixed leading and trailing edges of the horizontal stabilizer.

Initially the inspection of the horizontal stabilizers on the six flight test aircraft encompassed a small area of two shims and 24 potentially over-torqued fasteners, though Boeing concedes that scope of the initial problem has grown since first discovery in late June necessitating additional inspections and modifications of the flight test aircraft.

Boeing 787 vice president and general manager Scott Fancher said in June that the flight test aircraft rework would take between one and eight days depending on the amount of work required, however for the horizontal stabilizers on production airframes are expected to take significantly longer, say program sources

Next week from November 4-6, Boeing will dispatch a 787 on a marketing trip through western Europe with stops in Paris and Amsterdam. Dutch newspaper De Telegraaf reported Friday that Schiphol Airport officials had confirmed that the twin jet was slated to visit the Netherlands on November 5.

At stake is an order for up to 100 aircraft for delivery starting in 2014 to replace the carrier's older A340s and 747s. In May, KLM president Peter Hartman told Flightglobal the order had "stalled" because "the manufacturers are not willing to give us fixed dates and [aircraft] specifications."

Boeing appears set to give Air France/KLM the certainty they are looking for with a 787 visit to each airline's home base.

Program sources confirm that ZA006 ( N787ZA), the second of two General Electric GEnx-1B powered 787s, is slated to hit the road for the new jet's third European swing.

Air France/KLM has always selected General Electric or SNECMA (or CFM) engines for its aircraft, putting the GEnx powered 787 at the top of the airline's interest list for replacement, though the carriers said they would likely opt for a mix of the two.

With three years to go before A350's entry into service, negotiations between Airbus and GE to have second engine option along side the Rolls-Royce Trent XWB have largely disappeared from public view. In May 2009, GE said that once ZA005 and ZA006 entered flight test, the engine-maker believed it had an opportunity to "restructure discussions" with Airbus around adding a second engine to the program.

GE had previously been comfortable with offering an engine for the A350-800 and -900, but was reluctant about developing a competing engine for the -1000, which is set to go head-to-head with the 777-300ER powered by the GE90-115B.

Let's see if a trip to Airbus's backyard will push the engine back to the forefront.