Breaking: Electrical redesign to push 787 first delivery (Update3)

Boeing says its first 787 delivery will slide due to software and minor hardware changes to the electrical system, an assessment the company says will be completed within “the next few weeks.”

The airframer needs to implement changes to the software that manages and protect power distribution on the aircraft, as well as a minor hardware change to the P100 distribution panel to prevent foreign object debris (FOD) ingestion.

“We have successfully simulated key aspects of the on-board event inour laboratory and are moving forward with developing design fixes,”says 787 vice president and general manager Scott Fancher

Boeing says foreign debris “most likely” caused the November 9 fire aboard ZA002 that has halted 787 certification operations.

The company adds that “engineers have determined the fault began as either a short circuit or an electrical arc in the P100 power distribution panel” which sits against the left wall of the 787′s aft electronic equipment bay and manages power generated by the aircraft’s left engine.

Randy Tinseth, Boeing vice president of marketing, says: “Whatever this foreign debris was, it wasn’t something big – such as a tool – it was probably something small. We’re taking the right steps to ensure the power distribution panels are better protected against foreign debris.”

Boeing says it remains unsure how the FOD got into the P100 panel in the first place, and could have been in the panel for sometime, though the company concedes it won’t know how it got there.

As for the six grounded flight test aircraft, Boeing has not yet determined whether or not the design changes would have to be implemented before resuming certification activities, saying only: “Boeing is developing a plan to enable a return to 787 flight test activities and will present it to the US Federal Aviation Administration (FAA) as soon as it is complete.”

In the interim, Boeing will continue ground testing the fleet and may ferry ZA003 from Everett to Boeing Field in the near future.

Boeing says it is now “assessing the time required to complete the design changes and software updates that are being developed.”

24 Responses to Breaking: Electrical redesign to push 787 first delivery (Update3)

  1. Dave B. November 24, 2010 at 6:11 pm #

    Thanks Jon for the update. As always you’re right on top of things. Let’s hope this latest delay will be a short one.

  2. Wilbur Wrong November 24, 2010 at 6:17 pm #

    Jon,

    Please correct the last line, “This is a breaking story and will be update.”

    There ought to be a “d” at the end of update.

  3. Rob42 November 24, 2010 at 6:22 pm #

    Any comment on how the FOD found its way to the panel?

  4. John S. November 24, 2010 at 6:36 pm #

    “Whatever this foreign debris was, it wasn’t something big – such as a tool – it was probably something small.”

    So much for the reports that the fire was caused by a left behind tool.

    http://www.reuters.com/article/idUSN229809820101122

  5. iamlucky13 November 24, 2010 at 7:35 pm #

    There’s lots of possible root causes. Electrical systems often have an ingress protection rating (IPxy) describing their resistance to dust or other solids (x) and liquids (y). The protection could have been insufficient in this case or faulty.

    Or it could have been something left in there during manufacture. Or something that came loose inside.

    The good news: this doesn’t seem to be a deep-seated flaw. Let’s hope the delay is minimal.

    JohnS – Nice example of silliness in a media industry that can’t (and legitimately so) cite Wikipedia because of questionable veracity, but will take unverified claims from others at face value without having a clue of the problem. Then again, they didn’t even see anything wrong with using Twitter as an original source during the Iran riots, so this is no surprise.

  6. Steve November 25, 2010 at 1:30 am #

    FOD issue, despite triggering this incident, has always been secondary IMO. Of greater concern is what went wrong in the backup system / design / hierarchy. All I’ve heard from Boeing thus far are a bunch of vague statements coupled with the traditional spin. To say backup electrical systems including RAT kicked in and performed as expected doesn’t say much, really. The chain was severed somewhere in the middle. Maybe we’ll learn more details soon but I’m not holding my breath.

  7. Yazdi November 25, 2010 at 2:41 am #

    Your updates are incisive as always, John, but this time all is not adding up. Boeing has to reveal more on the back-up/ redundancy systems available and why they did not perform.

  8. Aero Ninja November 25, 2010 at 3:24 am #

    Does anyone know if the grounding was ordered by the FAA?
    Reading between the lines, I get the distinct impression that it was not a Bleing decision.

  9. Randolf Parkin November 25, 2010 at 4:27 am #

    This is terrible worrying!

    Boeing can explain the root cause of the fire (FOD), but they have discovered to their horror that their systems redundancy doesn’t work as expected.
    [Just like Airbus discovered with the recent Qantas A380 incident]

    Luckily, no aircraft or lives were lost, but both manufacturers and the flight authorities face a mountain of work over the next few months. And I for one can’t wait to read what the air worthiness directives decree until permanent fixes get implemented.

    OPEN QUESTION
    Can composite aircraft handle fire any better than conventional aircraft?

  10. DA-Pilot November 25, 2010 at 5:14 am #

    Hi John,

    thanks a lot for the (as always) wonderful insight.

    I’m sure Boeing will solve the problem. Too bad managers set impossible timelines for an otherwise wonderful and brave project. It makes it look worse than it is. The guys at Boeing have just re-invented how planes are built! Hurrah for those who take risks. I’ll keep the fingers crossed for a soon enter into service.

    A side topic: Do you have any news regarding the 747-8i? My company (Lufthansa) bought several of those birds, and I’m wondering when I could see them around.

    And thank you John, keep up the good work!

  11. AUG November 25, 2010 at 5:30 am #

    Has Boeing really established the root problem? No, they are speculating that a foreign object shorted the unit, they have not found the object, rather dubious and what caused the item to create the short right that moment is beyond me. Can Boeing tell us that the plane made severe movements that made the item move and create the short right at the time thye were pulling max load? It smells…

  12. Paul November 25, 2010 at 5:38 am #

    The A380 redundancy worked exactly as expected. That two separate wire bundles were severed by different pieces of debris was bad luck.

  13. HaHaHa November 25, 2010 at 5:49 am #

    There was absolutely nothing wrong with the A380′s redundancy systems. The aircraft suffered a major incident and still landed with none of the people on board injured or killed. The turbine disks of an engine are not designed to be stopped by the engine casing, so the fact the turbine released at all put the aircraft in grave danger. Only the fact the A380 is so well designed helped to bring it back to the ground more or less in one piece.

    If anyone is to blame in the QANTAS incident it’s Rolls Royce because the engine has an inherent flaw.

  14. Dr J P Sullivan November 25, 2010 at 6:48 am #

    Randy Tinseth, Boeing vice president of marketing, says: “Whatever this foreign debris was, it wasn’t something big – such as a tool – it was probably something small. We’re taking the right steps to ensure the power distribution panels are better protected against foreign debris.”

    -> Worth to note the use of the words “whatever it was” and “probably”. The statement is rather aiming to quell the public discussion, it will certainly not suffice to close the case.
    ->The investigation only *starts* with the identification of the root cause. The major issue is the analysis of the chain of events that ensued from the “initial spark”, to determine whether the system redundancies worked as designed. There are indications for a domino-like cascading failure. In case, Boeing has to define with the authorities where the systems behavior needs to be adapted or changed by modifying software and/or hardware. This is going to take some time, because the changes not only need to be defined, they need to be validated.

  15. Empire37 November 25, 2010 at 12:03 pm #

    Burned stringers after a 30 sec fire? Hmmm

  16. Andreas November 25, 2010 at 12:06 pm #

    “No, they are speculating that a foreign object shorted the unit, they have not found the object, rather dubious…”

    If a metal foreign object makes a shortcut in a 2000 Amp circuit (as the P100 panel is), the object will be vaporized. You won’t find it anymore.

    Best regards from Germany
    Andreas

  17. Patrick November 25, 2010 at 6:44 pm #

    Anybody know if they have condensation protection in these panels, or do they rely on rectifier heat to prevent it? For an arc fault, all you need is a tiny bit of filings, dust, or water vapor to break down air resistance. To have a bolted short circuit, you need enough metal to short between busses.

  18. T. Varadaraj November 27, 2010 at 1:44 am #

    Citing anonymous sources, Bloomberg is now reporting that it was a stray washer that caused the short. So it’s a workmanship and not a design issue and a minor one at that, though the consequences could have been catastrophic. Wish there was a way of turning the airplane upside down, shaking it and letting all the loose parts, tools and any other debris drop to the floor to be vacuumed up.

  19. Guru Josh November 28, 2010 at 3:38 pm #

    Does P100 have a liquid-cooled backpanel?

  20. kman November 29, 2010 at 3:39 am #

    Before their investigation is completed, by the way is far from being completed. Just astounding how anyone could believe, or make a statement that it was foreign object debris? They can’t find the foreign object don’t know how big it was, where it was, or how it got there! But, they are telling the media/public it was foreign object debris. Come on boy’s you better come up with a better one then that! Is Boeing changing their maintenance manuals to reflect this area of concern?
    Boeing Maintenance Section #787 #1 Check all power panel bolts prior to takeoff or landing! They have a tendency to vibrate loose we think! #2 Emergency Wrench located in P100 panel if it isn’t a post toastie already! #3 Hope everything is tight and hit the gas !!!!!!!!!!!!!!!!!!!!!!!!!!

  21. AUG November 30, 2010 at 8:35 am #

    i am aware, but you are unable to prove what cause the fire. As such to speculate that a foreign object caused the fire seems odd. In addition, why did this happen when they were pulling max amp through the system?

  22. Layman November 30, 2010 at 9:18 am #

    Let’s hope for Boeing’s sake that the A350 delivery date is delayed. It would be embarrasing if A350 customers get their planes before a B787 is delivered.

  23. Geoffrey C December 15, 2010 at 1:11 pm #

    I have come to a conclusion that Boeing needs to find a way to extract the oxygen out of the equipment bays, having an all nitrogen environment, where the electrical equipment is located. This does two things, which is to minimize fires, and corrosion. I saw the pics of the fire, and it looks like there was plenty of oxygen to feed the fire. I really hope that Boeing can look at this idea.

    Geoff C

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