Odds and Ends: 787 likely grounded to May; More Batteries; Boeing’s 10K

787 Battery short-term fix: The Seattle Times has this story which recounts Boeing’s effort to design a short-term fix to get the 787 fleet flying again. The scenario outlined in the article suggests the 787 will be grounded at least until May. The story also paints a picture that if the grounding lasts nine months, production would have to slow and financial impacts will start to hurt Boeing.

More on Batteries:

The A350: Reuters has this story on Airbus’ switch from lithium-ion to current technology batteries.

The New York Times has this story about the different directions Airbus and Boeing are taking.

The Puget Sound Business Journal has a good story about the evolving technology of lithium ion batteries and even though the 787 is currently the world’s most advanced airplane, battery technology has advanced beyond the 787. PSBJ787Batteries

On Other Stuff

Boeing issued its annual 10K report on February 11. We were already engaged in the PNAA conference Feb. 12-14 and didn’t have a chance to read it until after the conference. The following excepts are from the 10K.

747 Program: The accounting quantity for the 747 program increased by 25 units in 2012, reflecting the normal process of estimating planned production under existing and anticipated contracts. We continue to incorporate changes identified during flight testing into previously completed airplanes. First delivery of the 747-8 Intercontinental occurred in February 2012.

The production rate increased from 1.5 to 2 airplanes per month in May 2012. Ongoing weakness in the air cargo market and lower-than-expected demand for large commercial passenger aircraft have resulted in pricing pressures and fewer orders than anticipated in 2012. We have a number of unsold Freighter and Intercontinental production positions beyond 2013. If we are unable to obtain orders for multiple Freighter aircraft in 2013 consistent with our near-term production plans, we may be required to take actions including reducing the number of airplanes produced and/or building airplanes for which we have not received firm orders. We also remain focused on reducing out-of-sequence work, improving supply chain efficiency and implementing cost-reduction efforts. If market and production risks cannot be mitigated, the program could face an additional reach-forward loss that may be material.

[787 Information]

[787 test airplanes]: During the fourth quarter of 2012 we finalized an order for one of the three remaining flight test aircraft. We continue to believe that the other two 787 flight-test aircraft are commercially saleable and we continue to include costs related to those airplanes in program inventory at December 31, 2012. If we determine that either of the remaining aircraft cannot be sold, we may incur additional charges.

[787 grounding]: We are unable to reasonably estimate a loss or a range of loss at this time because such estimates are dependent on the ultimate finding as to cause and the timing and conditions surrounding a resolution and return to flight. Any such resolution could have a material effect on our financial position, results of operations or cash flows.

129 comments on “Odds and Ends: 787 likely grounded to May; More Batteries; Boeing’s 10K

  1. “Ongoing weakness in the air cargo market and lower-than-expected demand for large commercial passenger aircraft have resulted in pricing pressures and fewer orders than anticipated in 2012.”

    I’m just glad it has nothing to do with the 747-8, Boeing or competitive offerings.

    “The story also paints a picture that if the grounding lasts nine months, production would have to slow and financial impacts will start to hurt Boeing.”

    So if its “only” 6-7 months financials impacts will not hurt Boeing? I find that hard to believe.

  2. Looks like a simple case of ” A BATTERY TOO FAR ” .
    As far as financial impacts – get the Board some plastic belly buttons so they see which way they are going.

    And needing engineers ? In 2000, Harry S claimed the engineers could easily be replaced and were not as irreplaceable as they thought. The result was the largest white collar strike in History.

    All the actions seem to infer the classic definition of insanity.

    So why is BA stock doing so well ?

  3. psbj787batteries.pdf:
    “The technology of lithium-ion batteries has advanced far beyond what it was
    when the 787 was designed nearly a decade ago.”

    This was imho already the case in 2004 and Boeing thought about acting on this in 2007/8.
    ( see the FlightBlogger post on changing chemistry. )

    Why does this all look so “deemed unessential”, uninvolved and careless ?

    Everything about this plane appears to have more relations to Dr. House faking open heart surgery than anything comparable to watching Christiaan Barnard at work.

  4. This is the first I have seen where Boeing is working on a perminate battery redesign. The temp fix of a new box and equipped with the high pressure bottles to evacuate gases, fumes, debris, and fire should another battery need that protection is a good first step.

    • riiiight – eject molten metal similar to a magnesium flare over a populated area during landing or takeoff or cross country.

      Thats worse than ‘ blue ice ”

      Look up in the air – its a bird – its a plane – its a meteor ! NO its a dreamliner !!!

        • kc135topboom :
          It is not a magnesium flare (for the drematic).

          RIIGHT- I should have said ‘ burning magnesium ‘ instead of a flare on a parachute.

          So when the 787 is on the ground- post a NO ENTER ZONE or similar around or in line with the ejection ‘ chute-nozzle- barrel cannon ‘ and be sure no fuel truck get in line with the ejecta- since it can go off at any time ??

          Maybe just a red flag-plug on the chute that says ( ARMED-REMOVE BEFORE FLIGHT- AND DUCK ? ”

          Or an air traffic warning – attention – 787 approaching runway 360- all planes maintain a 600 yard separation from 787 5 oclock area. ?

          Turn it into a fighter aircraft that can shoot from the tail ??

          Wash state has legalized pot – the local managers must be using it in the executive dining rooms ??

    • kc135topboom :
      This is the first I have seen where Boeing is working on a perminate battery redesign. The temp fix of a new box and equipped with the high pressure bottles to evacuate gases, fumes, debris, and fire should another battery need that protection is a good first step.

      I believe the FAA and NTSB have made it clear that their main focus is the fact that the battery containment was needed in the first place. Improving the containment is certainly a consideration as well, but the main concern is that they don’t want to see battery fires on airplanes with any sort of frequency to begin with.
      So whatever needs to be done to strengthen the containment or modify it to cope better with battery fires than it did in the case of the JAL and ANA planes, I’m sure that’s going to be done – but it’s not going to be sufficient to get the planes back in the air. For that to happen, the cause of the fires has to be understood (and fixed).

  5. I suggest to store these batteries in external jetsonable pods like the p 38 had during the war.
    In case of need , fire up the APU for back up in case both engines starter generator fail and eject the external pods . This solution will not compromise the integrity of the high pressurized cabin of the 787 :) Flapa president.

  6. apropos the lagging chinese certification a less defamatory ( than the kneejerk stuff i’ve seen up to now ) explanation:
    “… awaiting a type certificate that the Civil Aviation Administration of China (CAAC) was not expected to issue until March.
    The Chinese were ready to issue the type certificate some years ago but, because of the 787′s development delays, the results of its preparatory work expired before the aircraft could go into service, industry sources say….”
    via: http://www.aviationweek.com/Article.aspx?id=/article-xml/AW_02_18_2013_p26-548327.xml&p=4

  7. Dominic, where are the spray you write about? I have not seen any spray of battery innards in any pictures, I have seen pictures of electrolyte running down the side of the containment, but that would hardly be a spray as in a jet of electrolyte. Sounds just a bit sensationalist to me.

    • en590swe, Dominic doesn’t seem sensationalist to me. Why do you feel so?

      Japanese safety investigators said on 19 January that the 787 battery overheated and sprayed burning electrolytes in a compartment beneath the cockpit because it was overcharged. Pictures of the damaged battery box revealed a charred interior, which is said to weigh 4kg (8.82lb) less than an undamaged unit.

      http://www.flightglobal.com/news/articles/damaged-ana-787-battery-sent-for-ct-scans-381339/

    • I’ve heard this argument a few times.

      Think of it this way: take a three-quarter full pan of potatoes immersed in water, heat it up, leave it at full heat for several minutes while boiling, cool off, remove pan and place on table, take picture of pan.

      Now picture the stove…

      In fact in the NTSB pictures of the JAL EE bay you can clearly see the dirty “boiled soup” on the floor and sprayed up on some of the other equipment.

  8. “787 Battery short-term fix:”

    It is a real shame that Boeing is wasting so much energy just to mitigate the very short term financial sheets whereas the root-problem is simply not addressed (ignored in fact) and will require even more financial investment in very little time to solve it when FAA wll reject the interim fix.

    Some people are dreaming…;)

  9. [787 grounding]: “We are unable to reasonably estimate a loss or a range of loss at this time because such estimates are dependent on the ultimate finding as to cause and the timing and conditions surrounding a resolution and return to flight. Any such resolution could have a material effect on our financial position, results of operations or cash flows.”

    Indeed “any such resolution could have a material effect on [Boeing's] financial position, results of operations or cash flows.” This harsh reality unfortunately has been rarely discussed so far. It’s like if the analysts were avoiding the subject as much as possible. Probably because it’s too painful to contemplate.

    • As long as Boeing does not positively know how long the grounding is going to last, they do not have to make an announcement.
      The analysts are in the same boat with Boeing, they have no interest in writing down the positions of their customers right away.
      And they probably need lots of time to formulate smart excuses for their unbacked ‘buy’ and ‘outperform’ ratings.

  10. Don Shuper :
    Wash state has legalized pot – the local managers must be using it in the executive dining rooms ??

    Maybe that’s why in the 787 Dreamliner parody of “Downfall” Hitler asks “Is Boeing on f–king drugs?”

  11. KDX125 :
    The analysts are in the same boat with Boeing, they have no interest in writing down the positions of their customers right away.

    From The Seattle Times article:

    “Adam Pilarski of consulting firm Avitas warns that though Wall Street currently accepts Boeing’s optimism that the 787 grounding will be relatively short, this forgiving attitude may not last.”

    “Boeing is trying to play it down to some degree, hopeful the solution is just around the corner,” said Pilarski. “But it may take much longer. And it could have a significant financial impact.”

  12. One thing I note with interest in the Seattle Times article is “That will seal the cells, keeping moisture out”. Again, moisture is mentioned in passing. I still hold on to the possibility that moisture shorted contacts at the top of the battery.

  13. I am sometimes amazed that even seasoned analysts lie Aboulafia don’t really understand the particularities of the B787. Often is said that Boeing replaced hydraulics with electrics, which is simply wrong. The B787 has a rather traditional hydraulic layout, using three systems (A380 & A350: two). The more electrical layout is primarily sought to eliminate the bleed air system. This decision again is not weight driven. Airbus’ approach might appear more traditional (or in Aboulafia’s words: backwards oriented), but was apparently reasoned by a less beneficial analysis of the bleedless design. The choice of lithium batteries is in no way associated with the general architecture, and in absolutely no way with hydraulics.
    The “more electric” does further not automatically require more battery power: the largest consumer of electric power is wing anti-ice, commercial loads and environemntal control system. All of those would be shut down immediately if power becomes scarce, and no battery in this world can power such systems for any meaningful time.

    So, Beoing went for the Li-Design for weight reasons. In my opinion the right decision. They have problems in the electric system design. That doesn’t prove that modern batteries are not useful for aircraft.

    Fun fact: the early B-52 models (up to version E) had bleed lines running from the engine to the fuselage, where the bleed air powered a turbine located in the fuselage. This turbine turned extremely fast, and tended to disintegrate. Boeing protected the rest of the fuselage with some sort of armor to prevent the pieces of the turbine blades from destroying other systems. The elimination of this system in the F-model allowed the usage of an integral fuel tank in the G and H-model, thus culminating in the most successful versions.

  14. From R.A.’s bio page: “He has a Masters degree in War Studies from King’s College, University of London and a Bachelors degree from George Washington University.”
    Zero tech background.

    Additionally Boeing has muddied the “detail waters” with care.

    You either have rather superficial systems description or intricate keyhole views on details.
    Comparisons by Boeing are invariably done in relation to the technology wise ancient 767 and not to state of the art planes like the A330/A340/A380.

    A lot is hidden behind smoke and mirrors and rather disingenious information presentation.
    You will find fibs like the “lowest cabin altiture for a (plastic) airliner” all over the place.

    My guess would be that the A380/A350 flight control systems are at least equivalent to the 787 usage of electrics ( and more refined at that ) The real electric hogs are the electric deice and cabin air conditioning. “complex” and “integrated” are not neccesarily positive design attributes.
    The A350 seems to demand less power for flight controls than previous Airbus types.

    • You do know the B-7X7 (later the B-767) and the A-300-B9/-B11 (later the TA-9 and TA-11, then the A-330 and A-340) were developed at about the same time in the 1970s, don’t you? The B-767′s debut was at the 1982 FAS and the A-340 debut at the 1985 PAS.

      Perhaps the developement of the A-340/A-330 (than the B-767/B-757) was slower due to the slower European culture of ‘design by committee’? Airbus was competeing with no one at the time of the A-340 developement on the contenent. Meanwhile, Boeing was developing the B-767 while at the same time competeing with Lockheed and MacDonald-Douglas.

      The B-787 has a cabin altitude of 6000′ compared to the A-350′s ‘traditional’ (read old technology) 8000′. How is that a fib?

      The A-350 uses less electrical power because it uses old technology systems, like bleed air for wing deice and cabin air conditioning. Meanwhile Boeing is trying to stay on the ‘leading edge of technology’ by developing new ways to accomplish comfortable and safe flying.

      The A-350 proved to be to heavy to use the RR Trent-900 engines from the A-380, they didn’t have enpugh thrust to lift the beast. The A-350 couldn’t even use RR’s most advanced engine, the Trent-1000 from the B-787. Since the A-350 uses old technology bleed air, the proposed RR engine would have been the Trent-1700, but again it didn’t have enough power to lift this new Airbus elephant, so they needed a new RR engine, the Trent-XWB, and it is the only engine offered. Then we find out the A-3510 neede even more thrust, so the Trent-XWB-92 is redsigned to have 97,000 lbs of thrust compared to the original 92,000 lbs of thrust.

      The A-350 has a sales gimic calling it the “XWB” for extra wide body, yet it is actually narrower than the airplane it is designed to compete against, the B-777. Isn’t that ‘false advertising’? Oh wait, I guess it is true, it is an A-3510 as it just keeps getting fatter and fatter in weight. You do know there is about a 125,000 lb weight difference between the A-358 and the A-3510 for about the same range and about a 100 seat difference in seat count (2 class), also about just 14 LD3s (including 5 LD3s for the additional pax baggage) or 5 pallets of cargo.

      So, tell me again about how “technological advanced” the ‘partial plastic’ the A-350 is over the B-787? Come on, let’s each put on our respective cheerleader hats.

      • kc135topboom :
        The A-350 proved to be to heavy to use the RR Trent-900 engines from the A-380, they didn’t have enpugh thrust to lift the beast. The A-350 couldn’t even use RR’s most advanced engine, the Trent-1000 from the B-787.

        So nothing to do with the fact that it’s a large twin then? Larger than a 787 and twinnier than an A380?

        kc135topboom :
        So, tell me again about how “technological advanced” the ‘partial plastic’ the A-350 is over the B-787? Come on, let’s each put on our respective cheerleader hats.

        No, let’s not.

      • So you tell me the 767 is a technology contemporary of the early A300.
        Which I deem correct. Only the 767 lags the A300 by a about decade. contemporary to the 767 is the A310 introducing partial FBW. A320, A340/A330 are fully FBW and generationally significantly ahead of the 767.

        Boeing advertised lower cabin altitude on the 787 as a first for airliners.

        Your A350 explanations don’t hold much water either, do they ?

      • RR never intended the T900 for the A350. A bleed version of the T1000 was proposed (as was a bleed version of the GEnx-1B, the GEnx-1A by GE).

        When the mk1 was revamped to be today’s offering, the thrust had grown so the T1000 and GEnx-1A offerings were already too small, so RR proposed the TXWB.

        The recent growth need for the 3510 is unfortunate from an engine perspective, but little different from the 777 with two different engines (albeit similar name).

        The XWB is in reference to the A350 mk 1 (same diameter as A330). At least its how it was pitched to the engine OEM’s at the time. So no intended reference to 787, but no doubt that is how everyone reads it (which was perhaps a hidden reason, who knows?). But as you say: the real comparison is the 777, and IMO the XWB reference should therefore be quite unambigous.

        • No sir, the A-350 went through 5 design changes before we got to the A-350 of today. It was originally offered (A-350 Mk. I, was also called the A-330-200LITE) as a warmed over, reengined A-330, what some are proposing today as the A-330NEO. Then the Mk.II had new tail surfaces, the Mk.III a new wing, then the Mk.IV with a composite fuselarge (all of these had the same A-300 cross section), and finally what we have today, the 11″ narrower fuselarge than the B-777, the XWB. Some of these versions had the GEnx-2B engine, until GE said no.

          These early designs were all rejected by the likes of IFLC, GECAS, and even Singapore, which were all some of Airbus’s biggest customers.

      • “The B-767′s debut was at the 1982 FAS and the A-340 debut at the 1985 PAS.

        Perhaps the developement of the A-340/A-330 (than the B-767/B-757) was slower due to the slower European culture of ‘design by committee’? ”

        I’ll leave the xenophobia for the blog owners to comment on and restrict myself to facts.

        The first flight of the A340 was in 1991, not in 1985 (unless Airbus did not just make it fly-by-wire but also fly-back-in-time). Launch was in 1987, first delivery in 1993. I guess you’ll find that was quicker than the 787.

        http://www.airliners.net/aircraft-data/stats.main?id=27

  15. From Top Boom !

    The A-350 proved to be to heavy to use the RR Trent-900 engines from the A-380, they didn’t have enpugh thrust to lift the beast. The A-350 couldn’t even use RR’s most advanced engine, the Trent-1000 from the B-787. Since the A-350 uses old technology bleed air, the proposed RR engine would have been the Trent-1700, but again it didn’t have enough power to lift this new Airbus elephant, so they needed a new RR engine, the Trent-XWB, and it is the only engine offered. Then we find out the A-3510 neede even more thrust, so the Trent-XWB-92 is redsigned to have 97,000 lbs of thrust compared to the original 92,000 lbs of thrust.

    —————-

    The TXWB, is ending 5-6 % better that the T1000 , and the TXWB 97 000 lbs version, with some RR T° improvements, will get the same SFC …
    The result, is 20% or more economics, vs the B777 ER … hard to ask for more today …

    I just hope RR will go ASAP to CFRP fans, since the very high pressure TXWB, is not a light engine ! 7,2 tons wet !

    Now, it’s up to the B777-XX (And GE) to send a credible answer … and when ??

  16. The B-787 has a cabin altitude of 6000′ compared to the A-350′s ‘traditional’ (read old technology) 8000′.

    Dear Topboom!
    Read the the specs. A350 has the same 6000′ cabin pressure as the B787.

  17. Schorsch :
    The “more electric” does further not automatically require more battery power: the largest consumer of electric power is wing anti-ice, commercial loads and environemntal control system.

    The 787 needs a more powerful battery because of its electric braking system. The Bombardier CSeries also has electric brakes, but uses traditional Ni-Cd battery power. That means Li-ion is not absolutely required for electric brakes, only a more potent battery is.

    Aboulafia says “Boeing needs a faster response time. It needs Lithium-ion.” I have no idea why the 787 would require a faster recharge from the battery. If anything, the faster recharge characteristic is actually an impediment from a safety perspective. The faster the recharge is the more prone to thermal runaways the battery will be.

    The MAIN battery is never used except when the aircraft is on the ground; or in flight for a transitory period during an emergency. And the other battery, the one for the APU, is used only to start the APU about once or twice per flight cycle.

    The irony here is that these two batteries play a minor, yet essential, role in the overall systems architecture of the aircraft. But they can bring an entire fleet of aircraft to a complete standstill for a prolong period.

    • Funny, Airbus has never claimed this. The only ones who ever do are the Airbus fanb… er cheerleaders. Airbus themselves haven’t ever made the claim, because it’s not true. A380 uses the same differential pressure as all the rest of the non-composite fleets. Only 787 and A350 are true 6000 ft cabins.

      • direct from the horses mouth:
        http://a380airbus.com/airbus-a380-cabins/

        The Airbus A380 Cabin and Interior
        The cabin has features to reduce traveller fatigue such as a quieter interior and higher pressurisation than previous aircraft; the A380 has 50% less cabin noise than the 747-400 and is pressurised to the equivalent of 1,520 m (5,000 ft) altitude versus 2,440 m (8,000 ft) on the 747-400.

        I’ve placed a question with Airbus to confirm.

      • Yes, I saw Howard”s reply in my mail and was compelled to come here to say he’s right…

        The A380 doesn’t have 6000 feet pressure – it’s *lower* at 5000 feet!

      • Well, that’s not what the manufacturer of the Cabin Pressurization system says, so like I said… you keep being that fanbo… er cheerleader. Sing another round of “Airbus Uber Alles” and waive your little Airbus flag. Maybe that’ll help change facts.

  18. anfromme :
    I believe the FAA and NTSB have made it clear that their main focus is the fact that the battery containment was needed in the first place.

    Why would a containment be necessary if Li-ion batteries are safe? ;)

  19. From The Seattle Times:

    “Good engineers will know how to get the heat out of these cells,” Battaglia said. “If anyone knows how to do that, it’s Boeing.” He added that the original battery design was probably done by the Japanese manufacturer, GS Yuasa, not Boeing.”

    That statement is unbelievably arrogant and contemptuous towards the Japanese company. Why is it then that Boeing has awarded a $208.8 million contract to GS Yuasa for 27 batteries ($8,000,000 – 425 lbs each) to replace the existing ones on the International Space Station?

    If we are to believe Vince Battaglia, from the Lawrence Berkeley National Laboratory in California, Boeing engineers know more about battery design than the GS Yuasa engineers!
    If the Boeing engineers are so good why did they accept the GS Yuasa design in the first place?

    Make no mistake, the 787 GS Yuasa battery looks to me like bad engineering indeed. But that design was selected by Thales, accepted and approved by Boeing and certified by the FAA.

    http://seattletimes.com/html/businesstechnology/2020373450_boeing787xml.html?prmid=4939#.USDlHOg1p-w.twitter

    • That statement is unbelievably arrogant and contemptuous towards the Japanese company. Why is it then that Boeing has awarded a $208.8 million contract to GS Yuasa for 27 batteries ($8,000,000 – 425 lbs each) to replace the existing ones on the International Space Station?

      I don’t know if the arrogance charge is really fair or necessary. Only half of this is actually a quote, and that is entirely out of context just as a result of the Battaglia discussion not really being central to the article as a whole. His quote itself is complimentary to Boeing, and nothing more. It may be based on work he has done with the company, and not necessarily in the commercial division. As was discussed in the PSBJ article, much has changed in Li Ion tech since those Yuasa engineers did their work, so the fact that this source feels Boeing now has the expertise to improve upon what does appear to be a wanting design is not necessarily as much of a condemnation of the original engineers as it may seem.

      I do wonder though how much this guy has actually considered the particular problem of getting the heat out of the cells within the context of maintaining the current certification of the system as a whole, and in a form factor that will fit within the space and weight constraints of the plane.

      • Boeing and expertise, hmm.

        Boeing seems to have been unwilling/unable/uninterested in going forward with a chemistry change discussed in 2008.
        ( and they knew they had a potential issue at hand )

        IMHO Boeings expertise may well be limited to facilitating faster battery exchanges ( via lobbying in Washington ) .

      • I was only addressing the question of arrogance on the part of Berkely lab guy.

        IMHO Boeings expertise may well be limited to facilitating faster battery exchanges ( via lobbying in Washington ) .

        No expertise whatsoever? Surely, not everyone at a company of that size is US educated? ;-)

      • “No expertise whatsoever? Surely, not everyone at a company of that size is US educated? ”

        If it exists it must be accessible.

        The observable “Blood–brain barrier” at Boeing speaks against this being accessible. ;-)

    • My very tentative guess going by the detailing is that the battery box was designed by US educated engineers at GSYuasa Lithium Power ( in Roswell, Georgia/US ).
      ( actually a simplistic copy of the regular NICd enclosure for aircraft
      imho indicating that the Li-Ion cells were assumed to be even more save than
      the regular NiCd ones also no projected maintainance )

      It just does not fit in with what I have seen from japanese engineers up to now.

      The Li-Ion battery that Securaplane offers has very similar details.

      Thales mentions these batteries exclusively in context of the 787 program.
      Thus I don’t think Thales actively decided on either the battery nor the charger/apustarter supplier. These parts were “gifted” on Thales.

      Who owns the battery certification : Thales or Boeing ?
      Thales as designed in liability buffer ?

      But we have heard nothing from Thales re the batteries in the last 2 month!

      • My understanding is:

        1- GS Yuasa designed the battery (in Japan or US).
        2- Thales selected GS Yuasa and its design.
        3- Boeing accepted and approved the design.
        4- The FAA certified the battery system.

      • topview of vented NiCd battery http://en.wikipedia.org/wiki/File:NiCd_battery_top.jpg
        the similarities are obvious. For the 787 battery the design errors start with nonvented cells arranged tightly as if vented.

        detail: NICd bat: top has quick release fasteners for maintainance. the Li-Ion bat has the top screwed on “no maintainance” ;-)
        for the 787 : though the cells have burstplates there is no provision in the box to enable controled discharge.

        the whole design revolves around the cells being “defined” 100% save.
        No further effort was undertaken to refine the design.

  20. kc135topboom :
    So, you don’t dispute what I said. The A-350 is to fat (heavy) and old technology?

    @ topboom

    If that’s the case how do you explain the fact that airlines have placed 600 + firm orders for an aircraft model that has not yet flown and which has a price tag of up to $320 millions a copy? According to your vision of things there must be a lot of foolish airline managers out there!

    You will have to accept the fact that the A350XWB, in all its variants, poses a serious threat to both the 787 and 777. And if the A350 was so fat and heavy and outdated like you pretend, there would not be all that pressure on Boeing to come out with a 787-10 and a 777X as soon as possible.

    If Boeing decided not to reply, or waited too long to respond, to the genuine threat posed by the A350XWB, the once great American corporation would become history.

    • Normand, you and I both know airlines buy airplanes based on their own needs and bottom line. Very few airlines are ‘loyal’ to Boeing or Airbus products to the extent they don’t even talk to the other OEM about new purchases.

      Almost no airplanes are sold just on the OEM’s sales pitch about its capabilities and promised performance. Airline customers take months, sometimes years evaluating an airplane model before signing up to buy them.

      Yes, the A-350 has about 600 orders, but the B-777 still has nearly 400 orders to fill too, and the B-787 is approaching 900 orders (including the 50 delivered to date). The listed price doesn’t mean a hill of beans as no one I can think of actually pays listed prices for new build airplanes.

      Price of an airplane, even a discounted price, is only one factor in deciding which airplane model to buy. Other factors include potential revenue the airplane can generate on one mission, costs of ownership, including operating costs and maintenance costs, etc.

      Boeing is responding to the A-350 with both the B-7810 and the B-77X programs. But right now the company is trying to get the B-787 issue(s) behind them. Airbus already did that by announcing they were switching from Li-Ion batteries to Ni-Cad batteries for the A-350. Since only one A-350 is currently built, they don’t have a fleet of them to modify. But no one is asking about the Li-Ion batteries that power emergency lighting systems in the A-380. Why is that? That emergency lighting is inspected and tested on some schedule, and don’t the batteries get recharged from the A-380′s massive electrical system? Is Airbus just going to quietly eliminate Li-Ion batteries on the A-380 just in case these batteries are banded for use in commerical aircraft?

      • “Boeing is responding to the A-350 with both the B-7810 and the B-77X programs.”
        Boeing is responding to the A330 with the 787 -8 & 787-9 and, more recently, the 787-10. How many ways does Boeing need to kill something?!

        “But no one is asking about the Li-Ion batteries that power emergency lighting systems in the A-380. Why is that? ”
        Hmmmm, maybe because their have been no incidents!!
        Airbus should thank you for soing their PR work for them.

        Should Airbus decide to get rid of the LI-Ion batteries on the A380, they would most likely announce it to the workd and let everybody else ask why Boeing continues to insist on using Li-Ion without really knowing how it behaves.

        By the way, if Li-Ion is banned form commercial aircraft use, both Airbus and Boeing would not be quiet about eliminating that technology.

  21. Normand Hamel :

    kc135topboom :So, you don’t dispute what I said. The A-350 is to fat (heavy) and old technology?

    @ topboom
    If that’s the case how do you explain the fact that airlines have placed 600 + firm orders for an aircraft model that has not yet flown and which has a price tag of up to $320 millions a copy? According to your vision of things there must be a lot of foolish airline managers out there!

    Yeah, but the airlines ordered 800 plus “DREAM-Liners” and look at where they are now!
    How many airlines will Boeing have killed off with the 787? Question is if Boeing can convince any AIrbus customers to switch to them after all of this plays out?

      • Why cancel when one gets such a sweetheart deal on the price? Problem is that a few airlines bet the farm on being able to expand based on the OEM’s advertised schedule.

        I would not be surprised if airlines start insisting on harsher penalties for delays, irrespective of labour action.

      • Labor action is selfafflicted by Boeing management, .Thus imho no recourse from customer complaints.
        Anyway I don’t see 787 delays caused by labor action.
        Not in the past and not in the near future. The process was stopped up independent of a strike or not.

      • But then you need to ask where you find 800 the vacant A330 slots. Oh and Airbus will be feeling the pressure now to do the A330 NEO, heavy “old fashioned” frame or not.

  22. kc135topboom :
    But no one is asking about the Li-Ion batteries that power emergency lighting systems in the A-380. Why is that? That emergency lighting is inspected and tested on some schedule, and don’t the batteries get recharged from the A-380′s massive electrical system? Is Airbus just going to quietly eliminate Li-Ion batteries on the A-380 just in case these batteries are banded for use in commerical aircraft?

    The A380 batteries are already certified. The A350′s are not. But if the FAA decides to ban Li-ion batteries from all commercial aircraft, Airbus would probably have to replace the emergency lighting batteries on the A380, even if the system has been working well so far.

    I am not sure what the NTSB will have to say in its final report about Li-ion batteries on board aircraft. Deborah Hersman said that the NTSB was necessarily against that technology. And of course we don’t know how the FAA will react to whatever report the NTSB will produce.

    But Airbus did not wait for the NTSB and FAA to make up its own mind about the technology. They decided to switch to Ni-Cd to save themselves a lot of trouble. The fact that Airbus already had a plan “B” in place is because they knew that Li-ion was risky. And contrary to Boeing with the Dreamliner, Airbus has tried to remove as much risk as possible with the A350.

    I believe the main reason why Airbus acted so swiftly is because they are in the middle of certification, and if a new system is required it’s the best time to implement one. But in the end they have probably figured out that the flying public would be reluctant to fly on board aircraft equipped with Li-ion batteries.

    Boeing will now have to sell the Li-ion battery concept to each of the following parties:

    1- Flying public.
    2- Political authorities.
    3- Governmental agencies (NTSB + FAA).
    4- Airlines.
    5- Insurance companies.

    • That is mostly correct. Yes, the batteries on the A-380 are certified, but so were the batteries on the B-787.

      Airbus had been proceeding all along with Li-Ion batteries for the A-350, that is up until the B-787 grounding because of them. I didn’t think Airbus actually had a plan B, but I was wrong. They quickly transistioned from Li-Ion to Ni-Cad after it became apparent to everyone the problem is with the batteries and not the B-787. I am sure one of the activities going on now with A-350 MSN-001 now is modifying the electrical system for the battery change as it was most likely built with Li-Ions in mind.

      “Deborah Hersman said that the NTSB was necessarily against that technology”.

      I had not seen that statement from Ms. Hersman, but if that is what she actually said, that is very unprofessional for the NTSB to come out with a negitive opinion before its investigation is completed, esspecially for the Chairperson of the NTSB to say such a thing.

      I agree, Boeing does have to convince the flying public, FAA, EASA, NTSB, JTSB, etc. the batteries are safe, assuming Boeing stays with Li-Ions.

      But, most of the flying public have no idea what kind of airplane they are flying on, or who built it. In that respect, the entire industry has a PR problem.

      As far as the politicians go, who really cares what they think. All they ever want to do is showmanship in front of the public eye. They won’t do anything about it anyway.

      Do you know where is the most dangerous place in Washington, DC is? Standing between Chuck Schumer and a TV camera.

      • I am sorry but I made a typo. The statement should read “Deborah Hersman said that the NTSB was not necessarily against the technology.” I apologize for the confusion the missing word brought to the debate.

        The original statement surprised me as much as my erroneous statement, the one with the typo, surprised you. That’s why I eagerly await the NTSB final report to see if the NTSB will recommend a ban on Lithium-ion batteries, or if it will only recommend additional safety measures.

    • Normand Hamel :
      I am sorry but I made a typo. The statement should read “Deborah Hersman said that the NTSB was not necessarily against the technology.” I apologize for the confusion the missing word brought to the debate.
      The original statement surprised me as much as my erroneous statement, the one with the typo, surprised you. That’s why I eagerly await the NTSB final report to see if the NTSB will recommend a ban on Lithium-ion batteries, or if it will only recommend additional safety measures.

      Thank you for the correction to her statement. I still think it is unprofessional because the NTSB should remain as neutral as possible.

      • Could you explain what you see as unprofessional in Ms. Hersman’s statement?

        “No fundamental unfittness of Li-Ion tech” is a (professional) statement of position.

      • She may have said that while answering a question. Whatever the context, it may have been stated to point out that the NTSB has no particular bias against Lithium-ion.

  23. KC135TopBoom :
    But, most of the flying public have no idea what kind of airplane they are flying on, or who built it. In that respect, the entire industry has a PR problem.

    That’s true for most aircraft except the A380 and the Dreamliner. The A380 because it’s the largest passenger aircraft in the world. The Dreamliner because of all the hype that surrounded the launch; also because of the multiple manufacturing delays it had to face before it entered service; and more recently because of the safety concerns that still keep the entire fleet grounded after more than a month.

    • Seems to have been first published around Feb. 7 ?
      archive.org does not have a trawl yet.
      Also google has the 404 document in it’s cache. That would indicate some (initially) missing links.

      Which road will they take with it. Suffocating visitors in PR and Newspeak or publish some tangible facts?

  24. If I recall correctly, Ms. Hersman claimed that NTSB were not in favour of anything in an aircraft that could ignite in an uncontrolled manner,(not her exact words) and this is certainly what Li-on batteries have demonstrated an ability so to do “in-spades”

    • What she said is that fires are not something they expect on board aircraft. When I read the original statement I interpreted it to mean that fires are not tolerated, even if they are contained.

  25. “But no one is asking about the Li-Ion batteries that power emergency lighting systems in the A-380. Why is that? ” Maybe because they don’t have thermal ‘events’ at a rate of 1:50,000 flight hours?

    Just a thought.

  26. Don Shuper :
    Check out this BA site for facts re 787 ?
    http://787updates.newairplane.com/787-Electrical-Systems/Batteries-and-Advanced-Airplanes#

    What Boeing are saying is basically what their specification would have said when they issues requests for proposals for the 787 battery .
    What essentially is missing are the following items:
    Must demonstrate reliability.
    Must demonstrate that they are safe.
    Those in my opinion are glaring omissions from the quoted Boeing article.

    • But but but – its the BA official position ! and the PR team worked hours on it !

      I’m shocked anyone would question it !! :_P

      and there is other info on that site

      After all – that presentation must have worked in the board room!

      then power point rangers no doubt got high fives- and now they want to spread the . . . . uh word ??

      Gnight all

  27. Normand Hamel :

    airtommy :Dear Topboom!Read the the specs. A350 has the same 6000′ cabin pressure as the B787.

    So does the A380.

    Some people live by the motto, “Let’s not cloud the issue with facts!”
    He was very unclouded yesterday.

  28. en590swe :Dominic, where are the spray you write about? I have not seen any spray of battery innards in any pictures, I have seen pictures of electrolyte running down the side of the containment, but that would hardly be a spray as in a jet of electrolyte. Sounds just a bit sensationalist to me.

    Try opening your eyes. Your comment sounds like that of someone in denial.

  29. Considering that Boeing appears to be fixated on the battery it looks to me like the possibilities are:

    a) Problem is confined to the battery, it can’t cope with the load of buffering an inherantly unstable electrical system, and all Boeing need to do is cool it better annd improve the containment.

    b) Boeing are publicly concentrating on the battery containment as that is the only thing they know how to fix at the moment, and can show progress on, while they work on finding out what happened .

    Let’s hope it is case a)

    • Boeing speak off “complex and integrated” in context of the battery.
      I do not have the impression that Yuasa designed the cells used for just 6 month service life.
      Also this would be completely contra the expressed product design objectives : low/zero maintainance and long check intervals.

      Thus there might be another possibility around:

      c) The batteries are abused by an intrinsic property of the 787 electrical design.
      Either component interaction, setup of the ground return network, large inductances in supply lines, .. whatever.
      If they cannot harden the battery the scope for fixing growth by serveral magnitudes.

      lastly
      d) Boeing is still trying to effect a political solution: “Dispense for being Boeing”.

      apropos: How does the FAA handle Airbus certification items. Is that also done by Boeing employees posted to FAA work now ;-?

      • If it is point c), and comments seem to indicate that Li-Ion is intrinsic to some systems (brakes) then “Houston, we have a problem” and a 6 month grounding would be a light let off and many frames will be nearer 5 years delayed!

        It will be getting hard for Boeing to convince customers that they should be launch customers for future new programs, like 777X

      • propos: How does the FAA handle Airbus certification items. Is that also done by Boeing employees posted to FAA work now ;-?..

        well maybe not IF SPEEA goes on strike

        Chief engineer already said the company line ” we dont need no engineers “

  30. A very interesting conclusion from Boeing PR !

    Now, the “Cell/Hour” count, is in the 2,2 million, non flight hours included !
    Next to come the Atom / Second Trillion statistic count that may help to convince Deborah to wait some time, for the next battery fusion ?? !

    http://787updates.newairplane.com/787-Electrical-Systems/Batteries-and-Advanced-Airplanes

    —————————-

    Since entering service, Boeing 787 Lithium-Ion batteries, each with eight cells, have logged more than 2.2 million cell-hours on the ground and in the air during more than 50,000 flight-hours. No battery-related incidents occurred before January 2013, when the airplane experienced two events.

    —————————–

    No more to comment !

    • Some fun facts:
      2.2e6 cell hours is 77 battery years ;-)
      correcting for prototypes, labtesting, .. this “supplies” 50 frames for ~250 days each with 2 batteries.

      50,000 hours in flight is the first reliable value on real utilisation.
      also 50,000 flight hours is the Boeing equivalent of 800,000 cell hours.;-)
      5000 hours were done in flight testing. i.e. customers did <45,000 hours.

      Under the assumption that the 50 delivered frames were on average 200 days ( first ~500days, last ~30days ) available I get about

      4.5 flight hours per day and customer frame.
      (ref: A380 : 156.000 hours in 2 years for an average of ~14 frames : ~~15h/day)

  31. Statistic’s… a Magician stuff ??

    Just imagine 800 B787 flying 12 hours a day, at the end of the decade …
    They could get … in the state of today’s art …
    One melted battery every 2-3 days !

    Japanese fondue ??
    Or Boeing Electro Shock ??

    Since they seem to have found more “may be” “deformed Cells” in fact the second APU battery on the first ANA grounded plane (It took me some delay to understand well the Reuters info !)

    http://www.nytimes.com/reuters/2013/02/19/business/19reuters-boeing-dreamliner-japan.html?partner=rss&emc=rss&smid=tw-nytimes&_r=0

  32. MartinA :
    …Problem is confined to the battery, it can’t cope with the load of buffering an inherantly unstable electrical system…

    That’s my favourite theory.

  33. 50k hours with 2 batteries at 8 cells each makes:
    50k x 2 x 8 = 800k cell-hours.

    Of the 2200k cell-hours, 1400k have been performed in testing.
    A single test rig (with 2 batteries at 8 cells each) would need 10 years of continuous testing (including nights, Sunday and Christmas).
    So how many test rigs do they have?

  34. MartinA :
    …Comments seem to indicate that Li-Ion is intrinsic to some systems (brakes)…

    Like I have mentioned in an earlier post (#39), the 787 has an electric braking system and because of that the battery has to be more powerful. But the CSeries also has an electric braking system but utilizes the standard Ni-Cd batteries.

    To summarize and clarify what this means:

    1- Aircraft equipped with electric brakes require a larger battery.
    2- That battery does not necessarily have to be Li-ion.

    Some people seem to think that the Dreamliner needs to have Li-ion batteries because they recharge faster. That is a myth. The only reason is to save weight.

    • Good point, but then why are Boeing so determined to stick with Li-Ion? There seems to have been questions about this for 4 years.

      • On the A350 Airbus would have saved 175 lbs by using Li-ion batteries. Considering that the A350 batteries are three times less powerful than the 787′s, that translates to a saving of several hundred pounds for the Dreamliner. It’s a huge incentive.

      • Just for the fun of it:
        The 787 has _2_ 30Vnominal ( 8 Li-Ion@3.7V cells) batteries of 65Ah each ~= 1.95kAh. for the ship : 3.9kWh

        The A380 has _4_ 24Vnominal ( 20 NiCd cells ) batteries of 50Ah each ~= 1.2kAh. for the ship : 3.8kWh

        The A350 has _4_ batteries. ( and is said to have slightly less energy hunger )

        My educated guess ( hello Howard ) is that each battery will demand slightly less capacity than the A380 ones.

        This would fit in with the notorious Saft VL4* series of cells ~40..45Ah. ( which have comparable (dis)charging characteristics of the Yuasa cells )

        alternative ( Airbus choice? ): take the A330/340/A380 battery ( SAFT 505CH, 505CH2, ..) or a 21/22 cell variant?.

        My assumption is that Airbus did not taylor fit the electronics
        to some faint battery properties.

        ( reference links available for all information )

  35. Howard :
    A380 uses the same differential pressure as all the rest of the non-composite fleets. Only 787 and A350 are true 6000 ft cabins.

    Andrew, you may be right to point out that the A380 does not have a 6,000 ft cabin altitude. Apparently the correct figure is 5,000 ft.

    Wikipedia:

    “The cabin has features to reduce traveller fatigue such as a quieter interior and higher pressurisation than previous aircraft; the A380 has 50% less cabin noise than the 747-400 and is pressurised to the equivalent of 1,520 m (5,000 ft) altitude versus 2,440 m (8,000 ft) on the 747-400.”

    http://en.wikipedia.org/wiki/Airbus_A380

  36. Howard :Funny, Airbus has never claimed this. The only ones who ever do are the Airbus fanb… er cheerleaders. Airbus themselves haven’t ever made the claim, because it’s not true. A380 uses the same differential pressure as all the rest of the non-composite fleets. Only 787 and A350 are true 6000 ft cabins.

    Quite right Howie. As others have already pointed out, with references no less, the A380 does not have a 6000 foot cabin pressure like the 787 but rather only a 5000 foot cabin pressure.

    Isn’t it wonderful what one can find out when one spends more time doing some research rather than devoting ones time to making snide remarks?!

    • Google is your friend. Try A380 cabin pressure TTTech. they made the cabin pressurization system, and their PDF has a nice little performance graph of cabin altitude vs. aircraft altitude. A380 is quite conventional.

      • I went on a long search in the wee hours since I couldn’t sleep last night. Seems Airbus itself is coy and only claims “more comfortable cabin altitude”, Hamilton Sundstrand (pressurisation system supplier, TTTech is a subcontractor for IT parts within that system) claims “no more than 7,000 feet while flying up to 41,000 feet”:

        http://www.hamiltonsundstrand.com/StaticFiles/HS/Communications/General/Documents/A380%20Fact%20Sheet_June%202011.pdf (page 2)

        Of course, that doesn’t preclude a 5000 foot cabin altitude at normal (lower) operating altitudes. That’s probably part of the problem we’re having… the usual thing where a single-value statement is actually quite useless for a nuanced comparison when things depend on multiple factors (just like 747-8 “uses less fuel” than an A380, etc.)

        By the way, if you were going on the TTTech presentation:

        http://www.tttech.com/fileadmin/content/pdf/2-3-3-3/TTTech-Nord_Micro-Casestudy-A380.pdf (graph, bottom of page 3)

        … please note that none of the images there are actually referencing the A380! The aircraft shown is a twin… Also,the graph shows a cabin altitude approaching 8000 feet for an altitude approaching 40000 feet – clearly not within the limits stated by Hamilton Sundstrand.

        So in conclusion, we have a number of semi-authoritative / media outlets (not fanboys!) stating it’s 5000 feet, and they presumably got that figure from somewhere:

        http://en.wikipedia.org/wiki/Cabin_pressurization
        http://www.arabianbusiness.com/inside-a380-57068.html
        http://www.globalaircraft.org/planes/airbus_a380.pl

        (there are many, many more – but here is the Wikipedia reference most people will use, plus its sources)

        If this was not a typo somewhere (no-one seems to be correcting them, after all) then presumably this *was* an official PR figure relating to typical operation at some point. Of course, the reality is more complex, depending as it does on definitions and conditions, which leads Airbus to its “more comfortable” stance and HS’s qualified 7000ft @ 41000ft.

  37. Howard :Now why don’t you run a calculation of how long between A380 wing rib cracks?
    See isn’t schadenfreude fun?

    Do you actually have anything useful to say or is it all just sarcasm and cynicysm?
    Even if there are some accuracy issues, most other people here actually have something to say.

  38. Howard :
    Now why don’t you run a calculation of how long between A380 wing rib cracks?
    See isn’t schadenfreude fun?

    Seriously…?!

    This is only “fun” in the sense of the touch of soap-opera keeping me glued to the news. But apart from that I am in no way laughing at Boeing’s troubles. In fact, I was expecting improved containment would be the temporary fix some time before that option became a public talking point.

  39. Containment , spacing between the cells, a gaz (And melt matter)drain, and some monitoring improvements are the only solution to send the B787 in the air before summer … otherwise the drama may extend to the end of 2013 !

    • “L’A350 demande trois fois moins de puissance aux batteries de Saft que le B787 aux batteries du fabricant japonais, analyse-t-on chez Airbus.”
      google translate says:
      “The A350 requires three times less power than the batteries Saft batteries B787 Japanese manufacturer, does one analysis at Airbus.”

      It says “power ( requirement)” not “energy (storage)” ? i.e. Power requirement is 1/3 of the Dreamliner setup.
      I would expect Airbus to use the Li-Ion bat in a NiCd emulation mode first.
      i.e. not use intrinsic properties beyond reduced weight.

      Looks like Airbus was carefull to not taylor their systems too tightly
      to Li-Ion battery properties.
      Afaics they may have planned that in the next generation.

      A: Fly Li-Ion in less demanding usage : ( emergency lighting A380 )
      B: Fly Li-Ion in a central function but do not utilise special properties ( main and aux batteries A350 )
      C: Fly Li-Ion in all functions and utilise specific properties.
      (.. my thinking on how Airbus thinks. They never jumped into anything unprepared and unexperienced like Boeing did with the 787 )

      • Unless La Tribune did not take into account that the load was split between two units. In which case the power would be only one and a half times instead of three times more. Which would make more sense.

      • IMHO you are missing the different metrics.

        What laTribune reports is that the load on the batteries “Power consumed/required ( kW )” is one third of what the 787 draws from its batteries in regular use.
        On a.net an astonishingly large value of ~140A / ~4kW for the 787 was mentioned ( and 17A for the 777 ), sorry lost link)

        What I know for the A380 and 787 and postulated for the A350 is that the battery size ( Energy storage in kWh are similar @ slightly less than 4kWh divided into 2 batteries on the 787 and 4 batteries on the Airbus planes.

        Assuming the batteries are evenly used, A380 and A350 should have three times the endurange on batteries only than the 787. ( were does the 787 get its juice for minimal internal lighting from? the main/apu battery? Airbus has dedicated Li-Ion battereries for those. )

  40. Uwe :
    What La Tribune reports is that the load on the batteries “Power consumed/required ( kW )” is one third of what the 787 draws from its batteries in regular use.
    On a.net an astonishingly large value of ~140A / ~4kW for the 787 was mentioned ( and 17A for the 777 ).

    The 787 batteries should only draw that king of power when starting the APU and when activating the parking brakes on the ground, plus other minor lighting functions. Other than that I can’t see where and when the batteries would draw any power at all. Except in an emergency of course.

    • I would expect the APU starter to draw in the vicinity of “savely below” max rated current for the batteries ( 5C ~= 325A ) say around 275A?
      that would be in the range of 7..9 kW per battery and starter generator ? ( use both and you reach required UPM ( 50%N1 ?? ) faster )
      I haven’t found references to actual starter dimension power wise.
      What I’ve found was a reference to a single APU start taking ~15% of battery charge. plugging the numbers and taking some losses into account I get 90s..120s cycle time.
      Looks like my numbers are not glaringly wrong.
      I would assume the A380 and A350 APU start numbers to be 10..20% higher ( larger APU )
      explains why lump battery capacity is similar.

      ( just for a reference: the main engine starter ( GEnx-1B ) requires 350kW max )

  41. The best comments I can read, often are from Andrea Rothmans, from Bloomberg … not very precise, in thiscase, but not much has been seen !
    100 Kg more, for Airbus CAD-Nickel Battery !
    http://www.bloomberg.com/news/2013-02-15/airbus-to-use-standard-battery-for-a350-to-avoid-lithium.html

    info :

    Honeywell A350 APU, 1700 HP !
    http://www.flightglobal.com/news/articles/honeywell-completes-initial-ground-tests-of-a350-apu-339083/

    Hamilton B787 APU, 1100 HP
    http://www.prnewswire.com/news-releases/hamilton-sundstrand-auxiliary-power-unit-for-boeing-787-program-undergoes-successful-testing-52123507.html

    I doubt, the B787 APU, may use more power to strat than the A350 one !

    Refering to parking brakes , I don’t know … but I think they may be not need energy from another world too …

  42. Rensim :
    I doubt, the B787 APU, may use more power to strat than the A350 one !

    Well, I think you should. The A350 APU is more powerful only because it has a load compressor and the 787 APU does not. That’s because of the bleedless architecture of the Dreamliner.

    But the two starter generators on the 787 are considerably more powerful, and heavier, than the ones on the A350, and represent a huge moving mass for the APU battery to crank.

    In short, the power draw on the 787 APU battery is higher because the rotating mass is higher, even though the A350 APU is more powerful.

    • No ;-)

      If you look at the diagram for the GEnx Starter ( pdf link 1..2days ago )
      you can see that sustainer ( i.e. only friction, aerodynamic and nonadiabatic compression losses at starting UPM ) power requirements are about 2/3..3/5th of the
      required max power. That should scale with design mass throughput.
      generators are geared down from the turbine shaft. in contrast the bleed air turbine
      if fixed on the main shaft should produce quite a load during start.

  43. Rensim :
    Refering to parking brakes , I don’t know … but I think they may be not need energy from another world too …

    You don’t have to believe me because I know very little about the Dreamliner. But you can ask CM, like I did. If anyone on this blog knows a few things about the 787 it is CM. And the reason that was given to me by CM to explain why the MAIN battery was more powerful, is that the electric braking system requires the extra power to activate the parking brakes. And if I got this wrong CM will jump in to straighten the record.

    In regards to the APU battery I found the information doing my own research. I know that the APU and MAIN batteries are interchangeable on the 787. Which brings me to reason that if the MAIN battery is more powerful, so is the APU battery. And the reason I came up with to explain that is the higher rotating mass of the 787 APU starter generators.

  44. Thank you Norman !
    I just hope the A350 do not start the APU, with the bleed air loading everithing unecessarily !
    Yes, the B787 APU has two starter generators, and some more inertia to move !

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