us: investigation shows gov\'t approval of boeing 787\'s batteries should be reconsidered

WASHINGTON -The U. S.
S. Top accident investigators say the government should re-evaluate its safety approval for Boeing 78 7 lithium-ion batteries, raising questions about whether the plane\'s failure can be quickly remedied.
Switching to a different type of battery increases the weight of the aircraft
Fuel efficiency is one of the main selling points of 78 7.
Boeing was licensed on Thursday to conduct limited test flights under special safeguards
A key step in solving aircraft failures.
The planes have been grounded in the past three weeks.
Boeing needs to be able to test the battery in flight conditions before it can approve the solution.
Flights will take place in uninhabited areas and in
Flight testing and inspection
The Federal Aviation Administration said in a statement that flight surveillance was necessary.
The National Transportation Safety Commission is investigating a battery fire last month at Japan Airlines\'s 787 Dreamliner in Boston.
Deborah Hersman, chairman of the board, said the results so far contradict some of the assumptions that the system has obtained government approval for battery safety.
The NTSB survey showed that the fire was caused by multiple short circuits.
She says one of the eight batteries of the battery is a circuit.
This creates an uncontrolled chemical reaction called \"heat out of control\", characterized by a gradual increase in temperature.
Short spread-
She said she had a short circuit with other cells and caused a fire.
Hersmann said the findings were inconsistent with what Boeing told the FAA when it worked to certify the company\'s latest, state-of-the-art aircraft.
Boeing said its tests showed that even if it tried to induce short
She told reporters at a press conference that the circuit, conditions and any fire were contained in a battery to prevent heat from getting out of control and the spread of the fire.
The Boeing test also showed that the battery could only cause 1 smoke in 10 million flight hours, she said.
But nine days later, a full-day air carrier plane landed in Japan in an emergency, followed by a Boston fire.
Hersman pointed out that the flight time of the 787 fleet is less than 100,000 hours.
The plane that caught fire in Boston was delivered to Japan Airlines less than three weeks before the fire and recorded only 169 flight hours on 22 flights.
\"Two battery incidents have now occurred, resulting in less than two weeks apart of smoke on two different aircraft,\" Hersman said . \".
\"This survey shows that short circuits in individual cells can spread to adjacent cells and cause smoke and fire.
Assumptions used to prove the battery must be reconsidered.
\"All 787 people have been banned since January. 16.
In the absence of an end, stopping has become a nightmare for Boeing, which has ordered about 800 aircraft from airlines around the world.
The company\'s customers have been frustrated over three years after 787, as the first product was delivered at the end of 2011.
Analysts say Boeing loses money every time it delivers 787 units and increases cash consumption every time it delivers.
Investigators are still trying to determine why the first battery is low.
But the commission\'s findings appear to question whether the FAA\'s safety certification of 78 7 batteries is thorough and whether Boeing can solve the problem by adding some quick safeguards.
The FAA typically entrusts testing of the design of the new aircraft to the manufacturer, while supervising whether the testing meets the requirements of the agency.
The agency also relies to some extent on the expertise of the manufacturer\'s engineers, especially in the case of cutting
Edge plane like 787.
Following a fire at Boston Logan International Airport, Transport Minister Ray LaHood and FAA director Michael Hurta ordered a review of the design, certification, manufacturing and assembly of 78 7
The review is still in progress.
\"We have to finish this work before we conclude on what changes or improvements the FAA should make in the future,\" LaHood and Huerta said in a joint statement on Thursday . \".
\"Leading experts in this area are working to understand what\'s going on and how we can safely get these aircraft back into use.
But John gorlia, a former NTSB board member and aviation safety expert, said the NTSB finding means the government may ask Boeing to re-
Certified battery.
\"Certification is not completely painless and fast,\" he said . \".
\"It could be a big, painted-out thing.
The meaning of \"NTSB discovery\" is that if this can happen --
Security analysts believe this will not happen.
Then, security analysis is no longer effective, \"said Jon Hansmann, a professor of aviation at MIT and a member of the FAA\'s Research and Development Advisory Board.
Battery experts say Boeing can try to make more safeguards for batteries by using more smaller batteries and placing more insulation between them.
Or, they say, the aircraft manufacturer can switch to different types of lithium-ion batteries that have been approved for aviation.
The main batteries of some business jets are lithium-ion batteries.
Switch to another type of battery such as leadacid or nickel-
They say the CD battery is another possibility, but it also needs to change the charging system.
New battery-
Probably a revised charging system.
Prior to installation, it is required to be designed and tested by Boeing and approved by the FAA.
Boeing said in a statement that it is working to resolve issues regarding its testing and compliance with certification requirements, \"We will not hesitate to make changes to improve the testing process and products.
\"On the same day as Japan\'s emergency landing, FAA officials orderedS.
Operator of 787s
United Airlines with six planesto ground them.
Aviation authorities in other countries quickly followed suit.
Seven airlines in six countries have a total of 50 aircraft grounded.
787 is the first passenger plane to use lithium batteries widely.
In addition to being lighter, the battery charges faster, can store more energy than other batteries of the same size, and can be molded into strange spaces suitable for aircraft.
The Airbus A350, which is expected to go public next year, will also use lithium-ion batteries widely.
Manufacturers also want to transform existing aircraft to replace other types of batteries with lithium ion.
But in general, lithium batteries are more likely to be short.
If other batteries are damaged, a fire can be caused if there is a manufacturing defect or if it is exposed to an overheated environment.
In 2007, the FAA issued special conditions that Boeing had to meet for the use of lithium-ion batteries in 787, because the agency\'s safety regulations did not include the standards for such battery systems at that time.
Compared to hydraulic or mechanical systems, 787 is more dependent on electrical systems.
The battery helps run these electrical systems and is also used to power up-
Generate an engine at the rear of the aircraft.
The battery is manufactured by GS Yuasa in Japan.
Air Japan investigators investigating the cause of ANA\'s battery failure also found heat out of control.
Investigators ruled out the possibility of mechanical damage or external short circuit
Possible cause of initial internal battery short circuit --
Hersman said.
Investigators and technical experts are now looking for evidence of defects inside the battery, such as pink, wrinkles or folds, she said.
\"We are working on a number of scenarios, including the charging status of the battery, the manufacturing process, and the design of the battery,\" Hersman said . \".
\"At this point, we have not reached any conclusions yet,\" she said . \".
\"We really have a lot of work to do.
Donations released from the city of Minneapolis.