If, stress ‘if’ it is necessary to replace the heavy duty lithium ion batteries in the Boeing 787 Dreamliners to prevent the failures that have grounded the new airliner, the delays involved in designing and certifying the changes could be between 12-18 months according to a US report.
That report, by Seattle Times reporter Dominic Gates, focuses on the 2011 destruction of a new Cessna Citation jet by such a battery fire.
The Citation fire led rapidly to the replacement of its lithium ion battery with an older technology less volatile type of battery, and is now being followed up with a final solution that returns to lithium ion battery technology but within an armored box that is in the rigorous process of being certified to fully contain all of the potentially lethal consequences of a major malfunction like those which occurred this month in Japan Airlines and All Nippon Airways 787s.
It has been argued, at great length, in the more technical media, that such an option isn’t suitable for the 787 which is much more electric power dependent than any other airliner design, with requirements that have been compared to those of a larger suburban housing estate.
Dissenting analysis has argued that such an interim solution is workable if getting Dreamliners back into service, even without the regulatory authority to fly for long distances over oceanic routes far from emergency airports, becomes an acceptable course of action.
(This would not seem to offer any comfort to Jetstar, which was to start getting 787-8s in the second half of this year, for flights to Singapore, Beijing, Honolulu, Tokyo and Osaka.)
The US aviation media has been repeatedly quoting from assurances given by Boeing during the certification process for the Dreamliner as to how its design prevented incidents like those which led to the 787 grounding from happening.
Going on comments made by Boeing management during last night’s Q4 earnings conference call the company still has its head in 2008, when what now appears to have been a seriously wrong turn in the design and certification process was taken.
But while Boeing says that the 787 is safe, and that everything is under control and of minor importance, there should be no doubt that a maximum effort to identifying the causes of the failures and devise solutions is underway.
Boeing’s credibility is being constantly ripped apart by its past statements. It’s most recent commentary risks causing similar damage. The need to synch words with realities has not, as yet, sunk in, and when it does the past will bite it again.
So far the company has not embraced an offer of help from Elon Musk, the entrepreneur and engineer who heads the SpaceX private rocket launcher company and Telsa electric car maker, both with a track record for using lithium ion batteries with 100% reliability.
Musk has identified what he regards as a major flaw in the use of large cell lithium ion batteries by Boeing, as reviewed in the Flightglobal report.
“Unfortunately, the pack architecture supplied to Boeing is inherently unsafe,” writes Musk in an email to Flightglobal.
“Large cells without enough space between them to isolate against the cell-to-cell thermal domino effect means it is simply a matter of time before there are more incidents of this nature,” he adds.
Both Boeing and Tesla use batteries fueled by lithium cobalt oxide, which is among the most energy-dense and flammable chemistries of lithium-ion batteries on the market. While Boeing elected to use a battery with a grouping of eight large cells, Tesla’s batteries contain thousands of smaller cells that are independently separated to prevent fire in a single cell from harming the surrounding ones.
“Moreover, when thermal runaway occurs with a big cell, a proportionately larger amount of energy is released and it is very difficult to prevent that energy from then heating up the neighboring cells and causing a domino effect that results in the entire pack catching fire,” says Musk.
At this stage, the operational records of SpaceX and Tesla, and Musk’s commentary are of compelling interest, because like it or not, they may point to the solution.