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Boeing prepares plan for interim fix for 787
Boeing will propose to regulators as early as this week a short-term fix to bolster the 787's defenses in case of battery fires such as those that have kept the jet grounded for a month. The goal is to get the planes flying passengers again, according to multiple sources with knowledge of the matter, while Boeing works on a comprehensive redesign of the lithium-ion battery system that could take nine months or more to implement. (www.chicagotribune.com) Más...Sort type: [Top] [Newest]
A good day for that 767-300! Bad day for Boeing, they have to get this right, the first time. Some have compared to the DC10 pressurization problems, the main difference is that a 787 has not fallen from the sky yet, Lord willing it never will.
May I suggest a reduction in the hyperbole. Although I do have some issue with Boeing's behavior as this story unfolds, I believe both in Boeing's intellectual ability to 'solve' the problem and in the basic logic of their initial 'containment' approach. Understand that the 787 electrical system is unique in aviation history. It manages energy at levels heretofore only dreamed of (probably by some pretty geeky engineers). This particular design just pushed the envelope of LIon technology just a LITTLE to far. They got bitten simply because the LIon technology has such razor thin margins at the edges. But they designed a fundamentally sound architecture to cope with the temperament of these batteries. I firmly believe two things will save the day for Boeing. But first from the Boeing web-site, "After extensive testing, Boeing ultimately selected the lithium-ion type battery because it has the right functionality and chemistry to deliver a large amount of power in a short period of time to do a high-energy task like start a jet engine. It then has the ability to recharge in a relatively short period of time so that it is available for the critical backup role that it plays during flight." So, save-the-day-thing1: The incidents so far indicate clearly that the margin of error (in terms of energy) is small because there has only been one fire and the overheat incidents were contained by systems operating as they should. Yes,Yes, I know, fire bad, but bare with me. Remember heat in a LIon battery goes non-linear in a hurry. I have heard nothing that would lead me to believe there have been any malfunctions in the sense of system behavior outside of design spec. Save-the-day-thing2: Given Thing1, and any of the incident causing flight profiles so far, it should not take much reduction in some energy flow, either in or out of the batteries, to reduce the level of heat in the battery box(es) back to a normal operational range. Now, a quick reference back to the Boeing quote above, note, "the lithium-ion type battery because it has the right functionality and chemistry to deliver a large amount of power in a short period of time to do a high-energy task like start a jet engine." The APU in the 787 does not start the engines, the batteries do! I firmly believe this 'problem' is an operational profile problem. If they can retro-fit access to external power for initial engine starts, they will have more than adequate thermal margins for safe flight. All the fires and overheat incidents are during climb-out, while they are recharging from engine start done on the ground, without access to nice cool air at altitude. I do believe that because both charging and discharging generate heat, the current battery boxes are inherently unsafe with the current battery-start operational profile. Maybe it would be easier to retrofit external cooling for ground start, without more details I don't know, but I am sure it is a solvable problem.
The description of the 'fix' in the article is not so much a fix as a containment strategy for when this happens again. Not very comforting to future passengers, the airline customers or investors in Boeing who will all start to vote with their feet unless Boeing gets to the bottom of this issue and creates a proper fix instead of the current direction they are headed with containment.
This whole episode reminds me of the dangers of allowing engineers to make prudent business decisions. And before anyone cruxifies me for that statement, Steve Jobs had constant run-ins with his engineers and had to constantly ride herd on them to come up with solutions that made business sense. And he was proven right tima and time again. Boeing's so called interim fix may contain a proven danger from an engineering standpoint, but people who have a personal (butts in seats) or financial interest in a real fix don't care one iota about what the engineers think. Users form their own perceptions about safety and risk despite what engineers or the company says. And rest assured, Boeing is NOT saying the right things about this issue when people's lives are on the line.
This whole episode reminds me of the dangers of allowing engineers to make prudent business decisions. And before anyone cruxifies me for that statement, Steve Jobs had constant run-ins with his engineers and had to constantly ride herd on them to come up with solutions that made business sense. And he was proven right tima and time again. Boeing's so called interim fix may contain a proven danger from an engineering standpoint, but people who have a personal (butts in seats) or financial interest in a real fix don't care one iota about what the engineers think. Users form their own perceptions about safety and risk despite what engineers or the company says. And rest assured, Boeing is NOT saying the right things about this issue when people's lives are on the line.
I certainly agree with your assessment. The general public hasn't caught on yet as to how serious this is but as the media starts drumming it to death it will take a huge business toll. I have no interest in riding on a 787 with a containment box: no matter how much free Jack Daniels they serve. Lol
That is a novel temporary solution ( to say the least) for a problem that they don't know the cause of. I feel bad for Boeing.
I wonder why Boeing is not considering Ni-MH, Nickle Metal Hydride batteries. They are used in the Toyota Prius, and VARTA makes a 24 volt Ni-MH battery. The energy density of Ni-MH approaches that of Lithium-ion, and the technology is well proven.