News reports say that this is not an interim fix but a permanent fix to mitigate problems that may arise if there was another short circuit and thermal runaway in the cells of the battery.
Boeing proposed changes includes (according to media reports):
1) A fire proof case to house the the eight cells of the battery to contain any smoke and fire from the rest of the electrical and electronics in the two E/E Bays
2) Venting of any smoke and gases out of the aircraft through pipes installed in the new case. This is to ensure that smoke does not get into the cockpit or the cabin
3) Wider spacing between the the eight individual cells and ceramic partitions between the cells
4) Enhanced and improve monitoring of the cells with information presented to the pilots throughout all phases of flight on each of the battery cells.
5) New battery monitoring procedure to be performed by the pilots before, during and after each flight.
Boeing says that they have had made good progress on addressing the battery issues and that today's meeting was "productive" (whatever that means). but the blunt statement by the FAA tells it all:
Deputy Transportation Secretary John Porcari, FAA Administrator Michael P. Huerta and other FAA officials met with senior executives from The Boeing Company today to discuss the status of ongoing work to address 787 battery issues. The FAA is reviewing a Boeing proposal and will analyze it closely. The safety of the flying public is our top priority and we won't allow the 787 to return to commercial service until we're confident that any proposed solution has addressed the battery failure risks.The FAA is certainly not going to give Boeing a pass on this and given that the NTSB still has not determined the root cause of the short circuiting, the FAA is going to look over their proposal and more than likely have additional conditions and tests that Boeing will have to carry out.
A good thing is that Boeing has been in constant contact with the FAA about the investigation and their plans but it is still the FAA's decision whether to accept Boeing's plan and allow them to test and certify the fixes.
According to the reports that have been circulating for the past couple of days, Boeing is planning to get the testing, certification and fixes implemented so that the world wide fleet of 787s can resume flying by around late March to April.
So while the FAA is drawing a hardline (as evidenced by their statement today) they will undoubtedly take into account a couple of things:
1) Root cause of the short circuiting has not been determined and may not ever be known
2) The batteries, until January, did not exhibit any short circuiting and thermal runaway issues.
3) There is a substantial economic loss both a t the carriers that have the aircraft and at Boeing
Given the above, the FAA will probably move to allow Boeing to test and certify the fixes but I wouldn't be surprised if Boeing and GS Yuasa, the maker of the lithium ion battery look to make changes to the design to enhance the safe operation of the cells.
What Boeing is proposing are preventative measures to stop a battery issue from getting out of control. Without a root cause they cannot address the design of the battery that would prevent a recurrence of the short circuiting and thermal runaway. This is probably the best option that Boeing currently has and is probably also the most aggressive option.
I do believe that Boeing will be able to return the aircraft to revenue flights but it will not be until late April to mid May before that happens. In the meantime, Everett will add on at least 10 more 787s while Charleston will add 2 to 3 787s to those waiting to be delivered. I think the FAA will come back with a response to Boeing's proposal fairly quickly (within the next one week).
In some good news, the JTSB (Japanese Transport Safety Board) has discovered what caused the the fuel spillage from a JAL 787 on January 9th at Logan International. It was small piece of FOD (foreign object debris) that prevented the closure of a valve. During a test on the same aircraft later in January, there was another fuel leak. The second one was attributable to a micro switch that was painted in a protective coating. The painting had left behind a small piece of hair from the brush causing the the switch to lock. Boeing is going to make sure that the micro switches are not painted in the protective coating again.