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#1 |
Now. Do it now.
Join Date: Sep 2012
Location: UK
Posts: 22,767
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Boeing 787s grounded by Japan
What's going on with the "Dreamliner"? Grounded in Japan until further notice, a recent fire on board, fuel leaks, cracked cockpit window and some brake problems.......all on a very new product.
Mike |
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#2 |
Critical Thinker
Join Date: Jan 2009
Posts: 348
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Seems typical so far. The only item on the list of problems that is a concern for me is the electrical fire. They need to get to the bottom of that quickly. The rest seem like typical maintenance issues.
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#3 |
Illuminator
Join Date: Nov 2003
Posts: 4,286
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It should be noted that, as far as I know based on a news report this morning, Japan Airlines was the first airline to receive 787s. Any problem still remaining with such a new design would show up first in those planes.
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#4 |
Penultimate Amazing
Join Date: Jan 2003
Posts: 22,755
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FAA also ordered a safety review.
I don't think that a few hiccups is particularly unusual for a new model of airplane. But I did hear that they outsourced a lot more parts than previously. |
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#5 |
Penultimate Amazing
Join Date: Jan 2003
Posts: 22,755
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From the OP link:
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#6 |
Critical Thinker
Join Date: Jan 2009
Posts: 348
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Hmm... Lithium batteries in aircraft are a no brainer due to their capacity vs size/weight performance. But the Dreamliner and AB380 are the first two I have become aware of that use them.
This isnt likley to be any kind of fatal flaw...but it could be quite problematic. Most other aircraft used to use nicad batteries. But maintaining these batteries was expensive and had high labor cost. Nicad batts also routinely caused aircraft to be grounded for excessive time because doing repairs and capacity checks routinely take 2-3 days. No way around it. Parts and cells were also very very expensive. For the last 10-15 years sealed lead acid batteries have displaced nicads as the preferred power source. They were much cheaper and if there was an issue operators just replace them since they were 60-90% less in cost than nicads. By just replacing these lower cost batteries they drastically increased departure reliability. But replacing a nicad with a sealed lead acid was usually a straight forward process. The nicad and its replacement were usually of similar dimensions and electrical capacities. Keep in mind you can not just replace parts on aircraft because they fit. When the aircraft is certified it is done so with each and every chosen component in mind and it is all documented. Any deviation in any way from that type certificate must be accompanied by engineering approval. This includes using a different PN battery or battery type. The procedure for that deviation is known as a "supplemental type certificate" or STC. Once an STC is done it is logged in the aircraft logbooks with pertinent info including updated "weight and balance" info. Once an STC has been approved by the FAA many times it is approved not just for the one aircraft...but all the aircraft of that particular model. In some cases thousands of aircraft. Anyways...knowing that and looking at the Dreamliner battery issue....it could be a bit of a problem. Unless Boeing worked with more than one source for these batteries....there is likely only one supplier. Also due to the drastic performance of Lithium batteries...the size of the mount/cradle for these batteries is not likely to correspond to some other off the shelf, readily available battery since other batteries are almost exclusively nicad or sealed lead-acid. Any change from the current design will require engineering and FAA approval. Of course this can be fast tracked but your still probably looking at many days or weeks for the STC to be done followed by more time to outfit each airplane. The most likely scenario is that Boeing, the FAA and the battery manufacturer are all looking at the failed battery packs at this moment and are coming up with a plan to fix the issue with the current packs. This could be as simple as a tweak in the assembly process. It may also be a tweak on the aircraft such as additional cooling or ventilation. But if the battery has a difficult to spot flaw and this is the only battery approved..it could be a royal PITA for Boeing in the short term. Also if Boeing hasn't done so already they should be starting the process for alternative sources of this pack or looking into an STC for older more reliable lead acid batteries to be retro-fitted. |
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#8 |
Critical Thinker
Join Date: Jan 2009
Posts: 348
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From the CNN story:
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The rest of those items in the article are normal maintenance items. |
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#9 |
Penultimate Amazing
Join Date: Jan 2003
Posts: 22,755
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Some more on Lithium Ion battery fires:
Battery fires: keeping the Li-ion caged
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A fool thinks himself to be wise, but a wise man knows himself to be a fool. William Shakespeare |
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#10 |
Critical Thinker
Join Date: Jan 2009
Posts: 348
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typical compliment of batteries on a medium or large jet are main ship batteries and
various standby batteries. These are used to power various emergency systems such as standby gyro and nav, emergency lights etc in the event of a complete electrical failure. Emergency lights are for the passenger egress. The standby equipment is for safe operation for a period of time with complete electrical failure. I am not familiar with the Dreamliner and large fly by wire aircraft. It may have larger batteries beside main ship batteries to power electrical portion of control systems for the fly by wire as well. When the aircraft is in flight...these batteries are always being charged and all other systems power is supplied by engine drive AC and/or DC generators. The batteries are only there for reserve power during emergencies. |
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#11 |
Critical Thinker
Join Date: Jan 2009
Posts: 348
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If main batteries overheat there are usually battery disconnects that can be engaged.
For smaller standby batteries many times there are circuit breakers that can be pulled. But they are not always accessible by crew. The dreamliner though has the newer systems that have virtual circuit breakers. They are now remote controlled through a central computer. Problem is when you actually have a true thermal runaway...you can isolate the battery completely and it will still cook its self. Very rare...but it happens. |
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#12 |
Non credunt, semper verificare
Join Date: Aug 2003
Location: Sigil, the city of doors
Posts: 14,581
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Fancy that I remember discussion about the airbus at the time and the small problem it had and people telling its was a crap airplane. Not necessarly here. But i smirk that now the comment section of US based site are all "it is normal" reassuring tone whereas it was with Airbus "a flying coffin"
![]() Basically in both case there are growing pain and the first few years of life of an airplane are rife with small or sometimes big problem. They usually are sorted out relatively rapidely. I am still a bit surprised at the grounding action, I can't remember a fleet being grounded in recent time, even after the suspicion on airbus pitote... Phased replacement during maintenance yes but not downright grounding. Bad memory on my side maybe ? |
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#13 |
Illuminator
Join Date: Feb 2008
Posts: 3,876
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Sigh. My first reaction to this round of bad news was, "The name is still Boeing, but the quality is MacDac. When Boeing 'merged' with MacDonald-Douglas, the senior MacDac brass took over the Board and the executive suite of the merged entity. Boeing had a reputation for high quality aircraft; apparently, that wasn't profitable enough for the new company.
My husband commented that the battery problem not be a problem with the batteries per se, but rather that the charging mechanism is not working correctly. So right now they're probably trying to reproduce the problem and testing both further batteries and their settings in the planes to determine where the trouble is coming from. And, as another poster already noted, Boeing out-sourced a lot of work that used to be done in-house on this plane. There is a lesson here. |
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#14 |
Penultimate Amazing
Join Date: Jan 2003
Posts: 22,755
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FAA Relied on Boeing-Generated Battery Data
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#15 |
Penultimate Amazing
Join Date: Jan 2003
Posts: 22,755
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Praised but Fire-Prone, Battery Fails Test in 787
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#16 |
Critical Thinker
Join Date: Jan 2009
Posts: 348
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Sure seems that way. I was reading about Litium ion batteries the other day. They apparently have several fail safe mechanisms built into each cell. And that apparently goes for all type from cordless drill to phone batteries. Sure seems like a supplier problem. Funny thing is apparently the manufacturer of these particular units is a Japanese company. I also saw a picture of the battery pack in question. It was a complete melt down.
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#17 |
Director of Hatcheries and Conditioning
Join Date: Jul 2002
Location: Waiting for the pod bay door to open.
Posts: 38,616
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Continually pushing the boundaries of mediocrity. Everything is possible, but not everything is probable. For if a man pretend to me that God hath spoken to him supernaturally, and immediately, and I make doubt of it, I cannot easily perceive what argument he can produce to oblige me to believe it. Hobbes |
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#18 |
Director of Hatcheries and Conditioning
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It's not the only problem. Being Lithium batteries, you have to build a failsafe backup system that protects against thermal runaway. This failed, flammable brown liquid came out of the battery when it over heated, even though it never became so hot that it caught fire like the first one.
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Continually pushing the boundaries of mediocrity. Everything is possible, but not everything is probable. For if a man pretend to me that God hath spoken to him supernaturally, and immediately, and I make doubt of it, I cannot easily perceive what argument he can produce to oblige me to believe it. Hobbes |
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#19 |
Penultimate Amazing
Join Date: Jan 2003
Posts: 22,755
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Oh, my. Well, that's no guarantee of superior quality.
Wasn't it Sony or some other Japanese company that had an issue with lithium batteries for notebook computers catching fire a couple years ago? Sony has really gone downhill since the good old days. Their bonds are considered junk bonds these days. |
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A fool thinks himself to be wise, but a wise man knows himself to be a fool. William Shakespeare |
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#20 |
Penultimate Amazing
Join Date: Apr 2003
Location: 16 miles from 7 lakes
Posts: 11,032
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"Political correctness is a doctrine,...,which holds forth the proposition that it is entirely possible to pick up a turd by the clean end." "I pointed out that his argument was wrong in every particular, but he rightfully took me to task for attacking only the weak points." Myriad http://forums.randi.org/showthread.php?postid=6853275#post6853275 |
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#21 |
Thinker
Join Date: Oct 2010
Posts: 130
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Here is a PC world arctical from 2006 about the dell laptop recall, it lists models affected and claims Sony made the batteries.
http://www.pcworld.com/article/126735/article.html |
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#22 |
Philosopher
Join Date: Dec 2008
Location: Planet earth on slow boil
Posts: 7,848
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Quote:
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#23 |
"más divertido"
Join Date: Jul 2009
Posts: 17,888
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Japanese company makes faulty batteries that ground US-made planes sold to Japanese airlines? Wow.
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#24 |
Perfectly Poisonous Person
Join Date: Mar 2003
Location: Wacky Washington Way Out West
Posts: 4,309
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Which did not happen with the 777. They built a full prototype in a building to check all the wiring in place, but more easily replace in the Systems Integratoin Lab. It even had a full flight deck, etc. A paper about here.
They refused to do that for the 787, and just did the testing using the van that checks it out after it is built before first flights. |
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I used to be intelligent... but then I had kids "HCN, I hate you!" ( so sayeth Deetee at http://forums.randi.org/showthread.php?p=1077344 )... What I get for linking to http://scienceblogs.com/insolence/ ![]() |
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#25 |
Philosopher
Join Date: Jul 2006
Posts: 6,387
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You need to do a better job of making the batteries, and you need a better way of burning in the units before you install them. Nobody cares if 1% of your batteries fail during their month in the "airplane-mockup vibration/pressure/temperature/charge-cycling test stand".
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#26 |
Critical Thinker
Join Date: Jan 2009
Posts: 348
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Good point. The battery packs are "life limited" components. Typically battery pack cells or the entire battery pack must be changed out every 2 years give or take. There is also usually a recuring "cap check" inspection at various intervals. In many cases that is every 6 months. These Lithium batteries may have lengthier life limits and mid point inspections...I dont know. But the safety factor can actually be addressed in two distinct ways. 1) find out what led to the failure and fix it 2) rearrange inspection intervals so failures may be detected sooner. Sometimes when a defect is uncovered option 2 is the only recourse in the short term. I have seen many instances where a major defect was uncovered and because there was no immediate fix, inspection intervals were severely shortened and the aircraft put back in to service with a new inspection interval. In some case aircraft operated this way for years. If the Lithium battery inspection interval for capacity check is currently 1 year....the parties involved could shorten that interval to say...every 30 days and potentially feel confidant about returning the aircraft to service. Of course that depends on the circumstances and nature of the failures. Cap checks on packs like that take quite a bit of time...usually 2 days minimum. So operators have "rotables" or spare components that are on the shelf, fully inspected, and ready to go. This way the downtime is kept to a minimum by swapping out entire battery packs. The cap check of the removed battery pack involves charging for usually 24 hours. Doing a capacity check at rated amp hour (ah) and then fully recharging for another 12-24 hours. This usually exposes any weakness or issues with the packs and really puts them through their paces. I am sure this is an option they are looking at currently. I am willing to bet every battery machine available has these packs hooked up doing cap checks to see if a dividing line can be identified between good packs and bad packs. They will be looking at lot numbers/manufacture dates etc to see if there are any patterns. Funny thing is...sometimes issues like this are traced to one or two guys at a facility who read the tech data/assembly instructions wrong...lol. I am betting the initial fix will be to cap check and inspect every pack in every aircraft and all spares/rotables. When that is done the data gained will guide a new inspection interval in the short term that is likely to be drastically reduced to 7-30 days. |
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#27 |
post-pre-born
Join Date: Dec 2003
Location: Santa Barbara, CA
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#28 |
Philosopher
Join Date: Dec 2008
Location: Planet earth on slow boil
Posts: 7,848
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Didn't happen with the 777??
seems Boeings Chief engineer disagrees with you
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but what does he know? ![]() |
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#29 |
Philosopher
Join Date: Dec 2008
Location: Planet earth on slow boil
Posts: 7,848
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Does not draw power from the engines/??
Pray tell how do the batteries get charged then??? I suspect this is what you are referring to in terms of savings.
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Mainstream climate science sources • http://www.skepticalscience.com/empi...al-warming.htm • http://ossfoundation.us/projects/env...g/human-caused • http://arstechnica.com/science/2013/...e-responsible/ ![]() ![]() |
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#30 |
Director of Hatcheries and Conditioning
Join Date: Jul 2002
Location: Waiting for the pod bay door to open.
Posts: 38,616
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__________________
Continually pushing the boundaries of mediocrity. Everything is possible, but not everything is probable. For if a man pretend to me that God hath spoken to him supernaturally, and immediately, and I make doubt of it, I cannot easily perceive what argument he can produce to oblige me to believe it. Hobbes |
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#31 |
Director of Hatcheries and Conditioning
Join Date: Jul 2002
Location: Waiting for the pod bay door to open.
Posts: 38,616
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__________________
Continually pushing the boundaries of mediocrity. Everything is possible, but not everything is probable. For if a man pretend to me that God hath spoken to him supernaturally, and immediately, and I make doubt of it, I cannot easily perceive what argument he can produce to oblige me to believe it. Hobbes |
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#32 |
Critical Thinker
Join Date: Jan 2009
Posts: 348
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Not saying you are wrong. But you would have to show me something for me to believe that. These airplane operate for hours on end throughout the work day. I dont see how any significant advantage could be gained by charging a small battery pack during overnight checks just so it can power some small system throughout the day to unload 1/5000 of the aircraft's electrical load. That makes no sense.
And if you are saying these are huge batteries that power all systems....I am sure that is not the case. Banks of huge batteries to run systems will have a negative impact in the form of excess weight and space. Not sure if you realize the power requirements of a modern aircraft...but they are HUGE. Anyways...there may be some new design on the Dreamliner I am not aware of that has these batteries operating in flight. But in my 25 years of working on aircraft...I have not encountered it yet. |
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#33 |
Philosopher
Join Date: Nov 2006
Posts: 7,110
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Indeed. One leading suspicion is the failure occurred during an overcharge.
http://www.kansas.com/2013/01/19/264...batteries.html |
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REJ (Robert E Jones) posting anonymously under my real name for 30 years. Make a fire for a man and you keep him warm for a day. Set him on fire and you keep him warm for the rest of his life. |
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#34 |
Perfectly Poisonous Person
Join Date: Mar 2003
Location: Wacky Washington Way Out West
Posts: 4,309
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My thought exactly. There is a difference between a few squawks and a fire resulting in grounding.
I found this blog to have some interesting thoughts on it: http://leehamnews.wordpress.com/2013...ve-on-the-787/ |
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I used to be intelligent... but then I had kids "HCN, I hate you!" ( so sayeth Deetee at http://forums.randi.org/showthread.php?p=1077344 )... What I get for linking to http://scienceblogs.com/insolence/ ![]() |
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#35 |
Illuminator
Join Date: Aug 2006
Posts: 4,080
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Okay, here's the deal on not drawing power. The engines are bleedless, save for handling bleeds, they do not take customer air for anything. There are two big starter generators on the gearbox and everything required for the aircraft is powered electrically. ie electric hydraulic pumps, electric pressurization compressors, wing anti/de-ice.
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#36 |
post-pre-born
Join Date: Dec 2003
Location: Santa Barbara, CA
Posts: 22,524
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Yes, Fitter is more correct than I. I reread the article I used as a source and it was either not clear or I did not read for comprehension.
The 787 is different because it does not use bleed air but rather uses the engines to generate electricity directly. See here. |
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#37 |
Critical Thinker
Join Date: Jan 2009
Posts: 348
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here is a good reference covering the bleedless engines. Very different!
http://www.boeing.com/commercial/aer...7_article2.pdf Its also has a very rudimentary schematic Here is a pic of the actual battery. It is labeled APU battery. http://www.guardian.co.uk/business/2...liner-grounded Either way...these batteries are typically in charge mode when APU/engines are running or really at any time you aren't starting something. Back up and emergency batteries are typically charging during normal operation..which is 99.999 percent of the time. So it sounds like it now may be a suspected charging circuit. It could also be both parties saying the other is at fault...lol. |
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#38 |
Philosopher
Join Date: Jul 2006
Posts: 6,387
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Yep. It's sort of terrifying how easily this can happen.
That's why, if you're procuring mission-critical parts, it feels like you ask for $100 worth of materials-traking, certifications, inspections, inspector-certifications, and similar paperwork for every $1 worth of hardware. And it's not overkill, because any slightly more "casual" procurement has a million ways to go slightly wrong. |
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#39 |
Illuminator
Join Date: Aug 2006
Posts: 4,080
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Boeing 787s grounded by Japan
My bad, it seems it does have an hydraulic pump, should be two I'd think, on the engine. In my defence in development world we only run with hyds when the test calls for them specifically and I only ran one Trent 1000 during training. My apologies for if I misled anyone.
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#40 |
Illuminator
Join Date: Aug 2006
Posts: 4,080
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Interesting article on the FAA's review. http://www.aviationweek.com/Article....p25-537815.xml
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