Yes, that was what I meant - (not evil intent). If they are already thinking they need to do actual flight tests it seemed to indicate that they had a pretty good idea of what to look for in those tests. Of course, I can only imagine the amount of pressure they are feeling to get something resolved on this.
You can see in my post that I wasn't only suggesting that we have to figure out what's going because, yes, that is obviously required.. I was suggesting that without knowing what is going on, it's unreasonable to say something like "it's either the batteries or the charging system". It could be maintenance, or mechanical issues, or something else. It's curious that these failures happened so close together, and on the same airline. It's unlikely, but not impossible, that it's pure coincidence. As for the other incidents, not all Li-Ion batteries are created equal. Not only are there different chemistries involved (which lead to different results during failure), but there's as much difference between an aircraft Li-Ion battery and a laptop Li-Ion battery as there is between an aircraft LCD cockpit display and a cheap Chinese 15" LCD monitor. You can't judge the quality of one based on the other. After all, there are countless of millions of Li-Ion batteries (of much less quality) that travel on commercial airliners every day without incident - perhaps almost as many as there are people on those airliners.
I think it might mean they know less. I've been reading everything I can about this situation and it looks like they have turned over every rock, followed every lead, checked every variable and come up with nothing. In such cases, it is valuable to monitor the system in situ and see exactly what may be going on (if anything).
Couple things: 1. Saw a post on another thread. Boeing employee (engineer) said that they are pretty sure a this point that it is not the batteries. It looks like a control system issue. FWIW. 2. Saw this also regarding Boeing acquiring M-D. "Boeing's troubles could be traced to McDonnell Douglas purchase By Mark Lacter | January 29, 2013 9:51 AM With its 787 Dreamliner still grounded after battery fires on two planes, and no sign of when the wide-body aircraft will be back in the air, Boeing is under fire on many fronts. Too much outsourcing, too little testing, too great a technology risk - it's a full-fledged corporate nightmare. But to fully understand what happened, it might be helpful to revisit the 1997 acquisition with McDonnell Douglas (based in St. Louis but with a major operation in Long Beach). Seems as if the bean counters took control of the engineers - never a good thing. From New Yorker columnist James Surowiecki: Technically, Boeing bought McDonnell Douglas. But, as Richard Aboulafia, a noted industry analyst with the Teal Group, told me, "McDonnell Douglas in effect acquired Boeing with Boeing's money." McDonnell Douglas executives became key players in the new company, and the McDonnell Douglas culture, averse to risk and obsessed with cost-cutting, weakened Boeing's historical commitment to making big investments in new products. Aboulafia says, "After the merger, there was a real battle over the future of the company, between the engineers and the finance and sales guys." The nerds may have been running the show in Silicon Valley, but at Boeing they were increasingly marginalized by the bean counters. Under these conditions, getting the company to commit to a major project like the Dreamliner took some doing. "Some of the board of directors would rather have spent money on a walk-in humidor for shareholders than on a new plane," Aboulafia says. So the Dreamliner's advocates came up with a development strategy that was supposed to be cheaper and quicker than the traditional approach: outsourcing. And Boeing didn't outsource just the manufacturing of parts; it turned over the design, the engineering, and the manufacture of entire sections of the plane to some fifty "strategic partners." Boeing itself ended up building less than forty per cent of the plane. This strategy was trumpeted as a reinvention of manufacturing. But while the finance guys loved it--since it meant that Boeing had to put up less money--it was a huge headache for the engineers." 3. Also read several posts by M-D and Boeing people that it was McDonnell that ran Douglas into trouble, so they could not recover. Statements like "outsourcing everything as a method to cut costs" and when the Boeing engineer went to work on the 717 and the C-17 it was a mess. They were actually doing drawings for the C-17 by hand on velum... everyone else had CAD, but McDonnell was too cheap. All for what it's worth...
Lou thanks for posting the pictures of the grounded 787s on the last page. I flew two flights on the United plane you posted. I think it was Uniteds first 787 or at least the only one in service in early November. I was actually part of the group who (I also think) was the first to charter a United 787. Anyway in case anyone wants to see some video of that plane and part of our trip here's a video: http://vimeo.com/55310072
PUBLIC DOMAIN SOURCE NTSB Press Release National Transportation Safety Board Office of Public Affairs NTSB identifies origin of JAL Boeing 787 battery fire; design, certification and manufacturing processes come under scrutiny February 7, 2013 WASHINGTON - At a news conference today, NTSB Chairman Deborah A.P. Hersman identified the origin of the Jan. 7 battery fire that occurred on a Japan Airlines 787 parked at Boston Logan Airport, and said that a focus of the investigation will be on the design and certification requirements of the battery system. "U.S. airlines carry about two million people through the skies safely every day, which has been achieved in large part through design redundancy and layers of defense," said Hersman. "Our task now is to see if enough - and appropriate - layers of defense and adequate checks were built into the design, certification and manufacturing of this battery." After an exhaustive examination of the JAL lithium-ion battery, which was comprised of eight individual cells, investigators determined that the majority of evidence from the flight data recorder and both thermal and mechanical damage pointed to an initiating event in a single cell. That cell showed multiple signs of short circuiting, leading to a thermal runaway condition, which then cascaded to other cells. Charred battery components indicated that the temperature inside the battery case exceeded 500 degrees Fahrenheit. As investigators work to find the cause of the initiating short circuit, they ruled out both mechanical impact damage to the battery and external short circuiting. It was determined that signs of deformation and electrical arcing on the battery case occurred as a result of the battery malfunction and were not related to its cause. Chairman Hersman said that potential causes of the initiating short circuit currently being evaluated include battery charging, the design and construction of the battery, and the possibility of defects introduced during the manufacturing process. During the 787 certification process, Boeing studied possible failures that could occur within the battery. Those assessments included the likelihood of particular types of failures occurring, as well as the effects they could have on the battery. In tests to validate these assessments, Boeing found no evidence of cell-to-cell propagation or fire, both of which occurred in the JAL event. The NTSB learned that as part of the risk assessment Boeing conducted during the certification process, it determined that the likelihood of a smoke emission event from a 787 battery would occur less than once in every 10 million flight hours. Noting that there have been two critical battery events on the 787 fleet with fewer than 100,000 flight hours, Hersman said that "the failure rate was higher than predicted as part of the certification process and the possibility that a short circuit in a single cell could propagate to adjacent cells and result in smoke and fire must be reconsidered." As the investigation continues, which will include testing on some of the batteries that had been replaced after being in service in the 787 fleet, the NTSB will continue to share its findings in real time with the FAA, Boeing, the Japan Transport Safety Board, and the French investigative agency, the Bureau d'Enquêtes et d'Analyses. "The decision to return the fleet to flight will be made by the FAA, which underscores the importance of cooperation and coordination between our agencies," Hersman said. She also announced that the NTSB would release an interim report of factual findings within 30 days. Additional information, including a video of the today's media briefing, the PowerPoint presentation, the FAA's Special Conditions for the B-787 battery system, and related documents, can be accessed athttp://go.usa.gov/4K4J. The NTSB will provide additional factual updates as developments warrant. To be alerted to any updates or developments, follow the NTSB on Twitter at www.twitter.com/ntsb. NTSB Media Contact: Office of Public Affairs 490 L'Enfant Plaza, SW Washington, DC 20594 (202) 314-6100 Kelly Nantel [email protected] or Peter Knudson [email protected]
So can these batteries be designed so that a single cell that suffers thermal runaway does not take out the other cells? Pete
If every single cell was cased in a way the whole package had been cased I guess yes. But batteries that catch fire regularly are not acceptable anyway. I think they should change the type of batteries to maybe some kind of LiFePO4 cells. Heavier but far less failure prone.
Yes, it just takes more separation between cells, insulation between cells if necessary and more room in the A/P for the entire battery.
It doesn't really matter. As noted in the preceding article, the battery can exceed 500 degrees internally when shorted. Hanging it outside the A/P isn't going to make any difference. I will melt down from the inside out. Separation of the cells would make a difference.
IIRC, the forward battery is in lower lobe, just aft of the nose wheel well. Temps can get pretty high in the Electronics bay but nothing that should affect basic construction of the battery case. On the 777 and 767 the aft battery for the APU is located in the aft section of the aft cargo hold but again, temps don't get that high back there.
Would it be a huge thing to switch the 787 to NiCad batteries at this point? Would the charging system have to be totally re-done? I realize NiCads are heavier than the L-ion batteries.
Of course it could be done, but the question that will have to be answered first, within the upper echelons at Boeing, will be at what cost. Technical re-design and certification will take time, i.e. months, as in up to a year. Further add in the image impact. How many future sales and/or order cancellations will this cost. Boeing will do everything they can to get the current design back up and flying, even if it requires frequent replacement and/or operational restrictions (on use of the batteries). They will then work to update or change the system in the future.
Quick fix and after that a permanent solution. Question is, whether there is a safe quick fix at all and whether passengers will accept it. And if their quick fix doesn't work and there is a fire again or even a plane comes down, then they will be in big trouble.
It would and it would! [This is based on knowledge of batteries used in RC models, not "real" aviation btw.....] It could certainly be done, but Ni-Cads need to be completely discharged before recharging for example. Li-ion has no such constraint. Then the entire "conditioning" and "float" charges need to be completely different. As for going to Li-Po; You're living *very* dangerously there as of today! The model guys still recommend that they be charged in either ammo-cases or custom battery bunkers - Their storage capacity is great and they can take some abuse, but when they go, they *really* go....... I know I wouldn't want to fly with 'em on the plane. Cheers, Ian
I think this has to be the right answer. They need to get those planes in the air but they also need to assure the airlines that a permanent fix is coming and they will retrofit their planes for free. Basically they pushed the boundaries and made a mistake. If they don't address this and a fully loaded plane crashes I personally will never fly on one. I personally think Airbus has made the right decision. We are talking about aeroplanes here. You cannot pull over and put a fire out, so risk aversion is paramount. Pete
This image is already adding to the impact. This needs to be fixed by REAL airplane people, not executive management and not the bean counters. Image Unavailable, Please Login
