As Boeing's GEnx powered 787 initiated test flights to gather data on the operating environment of the aircraft's lithium ion batteries many questions still are circulating not the least which is when will the FAA allow the 787s to resume revenue flights by the world's airlines.
Here's a rundown of the latest news:
Lithium Ion Battery Investigation
The NTSB, in preliminary report, has narrowed down the origin of the fire to cell 6 (of 8) in the battery in the aft E/E bay of ZA183 (LN 84, JA829J). The thermal runaway ("an uncontrolled chemical reaction at high temperatures") was caused by several short circuits in cell 6 which propagated to the adjacent cells (primarily cells 5, 7, and 8). Cells 1 through 4 were also damaged but as you can see from the picture above, they weren't damaged as badly as the cells. The root cause of the short circuiting has yet to be determined but the NTSB is looking at various factors in the search of the root cause. These factors include design, certification and manufacturing processes of the lithium ion battery. They did rule out external short circuiting as well as any external damage that caused the cell to short circuit. Investigators will look at battery charging as well as as any other external factors that may have had affected the cell thus the NTSB has a long way to go.
Already though the NTSB is looking at the certification of the battery by the FAA charging that this battery should not have been certified under the special conditions that were set forth. Additionally, Boeing had predicted, based on their testing, that a smoke event from the lithium ion batteries would occur once in 10,000,000 flight hours. However, 2 smoke events have occurred in less than 100,000 flight hours across the worldwide 787 fleet. Thus NTSB Chairperson 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." Additionally, the NTSB said "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."
In other words, the certification process by the FAA and Boeing for the lithium ion batteries is severely flawed and if these batteries are to be used on the 787 then the FAA and Boeing needs to reconsider how these batteries are to be tested along with containment and monitoring along different failure modes because the fire did show cell to cell propagation whereas Boeing testing (and FAA sign off) did not show that it would occur.
The NTSB will release an interim report in about 4 weeks but it is not known if they would have found the root cause of the battery incident in Boston. Lastly, it'll be interesting to note if the JTSB would find a similar short circuiting cell from the ANA (ZA102, LN 9, JA804A) battery. Thus far both batteries have shown signs of thermal runaway and short circuiting though the ANA battery did not catch fire. Still there was significant high temperature damage to that battery.
Here is the press release from the NTSB on Thursday:
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 at http://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.
Resumption of 787 flights
Last Wednesday the FAA gave approval to Boeing to conduct a one off ferry flight of a 787 for China Southern Airlines 787, ZA382 (LN 43, B-2727) that was stuck in Ft. Worth, Texas for painting when the grounding occurred in mid January. The ferry flight was from Ft. Worth to Everett and had a number of restrictions placed on it to ensure the safety of the flight crew on board. The aircraft flew to Everett on Thursday and landed among a media circus gathered at Paine Field that evening. Later that night , the FAA gave approval to Boeing's request to conduct flight tests using ZA005 (LN 5, N787FT) for the purposes of gather data on the lithium ion batteries while in flight. Boeing will be looking to record data on moisture, vibrations and other environmental factors which may have contributed to the short circuiting of the cell. Additionally, Boeing is hoping to conduct test on possible containment and venting systems as well as a more robust battery monitoring system to mitigate the risks of another lithium ion battery thermal event. It is known that Boeing is working on a plan to submit per the FAA's emergency airworthiness directive that forced the 787 grounding. It is rumored that Boeing wold like to have this temporary solution on the customer airplanes and re certify them by the end of March though that may be very optimistic. Boeing would have to convince the FAA on the soundness of their approach (which is being characterized as interim). Additionally Boeing can forget, for now, on obtaining ETOPS 330 for the 787 based on the the battery issue as well as the other issues that has caused the FAA to imitate the 787 program review in early January.
There maybe some one off 787 flights to reposition 787s that are stranded away from the their home bases (like the Polish LOT 787 in Chicago). I don't have any data on the 787s that are stranded. Air India conducted several ferry flights from Delhi to Mumbai of their 787s. In my opinion, I believe the 787s can see a return to flights status around the April to May time frame. The FAA is not going to rush them back to the air but they won't be 1000% safe as Ray LaHood promises that they will be.
Battery Plan
As mentioned earlier, Boeing is drawing up a plan to return the 787s to flight and to resume deliveries. The FAA emergency airworthiness directive states "Before further flight, operators of U.S.-registered, Boeing 787 aircraft must demonstrate to the Federal Aviation Administration (FAA) that the batteries are safe.
The FAA will work with the manufacturer and carriers to develop a corrective action plan to allow the U.S. 787 fleet to resume operations as quickly and safely as possible."
This leaves a lot of leeway for Boeing to introduce a new battery protocol that would encompass monitoring, containment and venting in to the 787s fleet. However, given the seriousness of the problem, this plan is being viewed as more of a temporary step with a view that Boeing may have to completely redesign and re certify (under more presumably stringent conditions) the lithium ion batteries. The redesign and recertification may take up to a year to complete. Boeing is reiterating that they will continue to use the lithium ion batteries.
Production and Flight Testing
Currently between North Charleston and Everett, Boeing has 19 787s that are complete and need to finish the typical Boeing/customer flight and ground test program that occurs prior to delivery. There are 15 787s at Everett that are complete and 4 at Boeing Charleston. Boeing is adding about 1 airplane per week to that total as production is continuing full tilt at both final assembly sites not including 787s coming from the EMC. At this rate Boeing can double the number (to about 40) of 787s parked at both Charleston and Everett by the end of May if there isn't progress on the battery issue and a restart of deliveries. Boeing is planning to deliver at least 9 re-worked 787s in 2013 along with about 55 or more non re-worked airplanes in 2013. Some customers have already been alerted that near term deliveries will be delayed but I believe that the delays may extended into the summer due to the grounding. If there is an extended grounding, Boeing may free up room around Everett by conducting the B-1 flights of 747s, 777s, and 767s from Everett but have them land at Boeing Field to finish the testing and delivery process. This way spots can open up at Everett for more 787s that have to be parked. Additionally there is room at the tower ramp, Runway 11/29 and the south ramp area at Everett. On a brighter note, Boeing was able to finalize the order for 42 787s with American Airlines this past week. That firm order will comprise of 20 787-8 and 22 787-9 plus 58 options which would encompass all 787 derivatives. The first one is to be delivered in November 2014...about 21 months from now.
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