Japan restarts operating Dreamliner flights
Japan’s biggest airline- All Nippon Airways (ANA) has resumed Boeings 787 Dreamliner flights. It is for the first time for the Boeing 787 Dreamliner when its flights were resumed after the planes were grounded worldwide after two incidents on Japanese-owned planes involving overheating of the lithium-ion battery packs in January 2013.
The US and Japan had earlier grounded their Boeing 787 Dreamliner aircrafts due to concerns over it battery safety. Recently, a battery-fault warning on an All Nippon Airways Dreamliner in Japan forced an emergency landing. A battery overheated and started a fire in an empty 787 operated by Japan Airlines (JAL) at Boston’s Logan International Airport. The aviation authority of the US, the Federal Aviation Administration (FAA) ordered that 787s in the United States be grounded until their batteries are shown to be safe, the first such action since 1979. United Airlines reported a problem in one of its six 787s with the wiring in the same area as the battery fire on JAL’s airliner.
Why Lithium batteries?
- Unusually high energy density
- Can be moulded into a variety of shapes
Although all air-planes have batteries, but the Dreamliner requires powerful batteries because Dreamliner’s control systems are driven entirely by electrical signals in place of the hydraulic controls found in traditional generations of jets. So, Boeing depends in part on lithium-ion batteries, which provide quick and powerful charges.Designers needed something which is light in weight and at the same time gives high power output. So, they opted for Lithium-ion technology batteries which have an unusually high energy density, which means the units can be smaller and thus lighter for a given amount of power than traditional batteries.
Lithium-ion technology is the same technology that we see in in the batteries of most modern smartphones and laptop computers, where the demands are rather similar, but on a much smaller scale.
Another big advantage of using Lithium-ion units: These can be moulded into a variety of shapes and thus, provide flexibility to design and fit them in awkward places, which is a key concern when space is at a premium.
Airbus A380 superjumbo also uses the same technology in batteries but in the Drealiners these batteries are used on a much more extensive scale.
Now, with advantages, there is a potential disadvantage of using lithium-ion batteries:
- Lithium-ion batteries require more careful management than other types of battery due to the ‘Thermal Runaway problem’.
We all remember the reports in Newspapers, TV Channels about batteries in laptops and mobile-phones smoking and catching fire.Thus, Lithium ion batteries can be prone to what is referred to as thermal runaway as a result of the very of chemistry involved. As a battery reaches a specific temperature, it can start self-heating with potentially disastrous consequences.
Also these batteries are Vulnerable to problems and leaks of battery fluid. When the problem of leakage starts, the fuel can in turn ignite automatically.