The news here in NZ is reporting that the entire fleet of Boeing 787 dreamliners has been grounded due to safety concerns. Apparently it’s the first time such an action has been taken for a US designed plane since 1979.
I know there are a lot of aviation posters so what are your thoughts on the issue? Are there significant dangers or are the regulators being hyper cautious? What implications are there for Boeing as a company? The entire development of the 787 seems to have been plagued with problems, was the desig just too ambitious.
Apologies for the lack of links, I don’t know how to add them from my phone.
I’m not an aviation expert, but from what I’ve heard is that one of the large new batteries is running hot, and can cause a fire. It is far better to catch it now than later. The Japanese airline who had some and had a problem grounded them first, then the FAA, and I heard this morning Europe did.
It was unclear if the problem was a design flaw in the battery or inadequate screening, so that batteries with reliability issues got installed. If the former they may have a major problem, if the latter it will just take rescreening all installed batteries and improving the manufacturing test of them. I don’t think anyone knows yet.
Given the integration issues they had during development it could have been a lot worse. Things like this happen during ramp. Unless this is a major disaster, I don’t think it will hurt in the long term. The plane has a lot of advantages in fuel efficiency to keep selling, and Marketplace noted that unless they are grounded for a long time most customers awaiting delivery will never notice.
Lithium-ion batteries have some nice advantages, like relatively low weight, greater energy storage per unit of weight, and so forth which make them very attractive for aviation purposes.
They also have drawbacks, like a propensity to burn at incredibly hot temperatures or even explode when mishandled or damaged. The fires that result can be very difficult to put out. For example, Halon 1301 will not put it out (apparently, it just turns sparks shooting out of the fire from white to red). Water will not put it out. Lack of oxygen won’t put it out, because the oxide compounds in the batteries will happily supply oxygen to continue the fire. Needless to say, an essentially inextinguishable fire on board a flying aircraft is a Very Bad Thing.
Needless to say, any lithium battery that is part of an aircraft needs to be designed to high safety standards.
I am optimistic they’ll solve these problems. After all, airplanes are full with flammable stuff called “fuel” yet they don’t spontaneously explode on a regular basis. It’s a matter of properly managing and preventing potential hazards.
I think the B787 is the first airliner to be certified with lithium batteries. As Broomstick says, there are some significant drawbacks with these batteries and they have caused problems in passenger baggage and cargo before. Boeing needs to make absolutely sure that they’ve got it right. I guess they thought they had it right to start with but now they’re finding out they didn’t. There will always be teething problems with new aircraft, but Boeing needs to be very careful they don’t let short term commercial interests override safety. The problems that plagued the DC10 ultimately destroyed its chances of being a successful airliner.
My aunt works in a police station which burned down a fortnight ago due to lithium batteries. It can’t be that uncommon. Thing is that some of this happened in flight yet no one died suggests to me, as a naive layman, that they have great fire supression - in which case nothing huge to worry about - is that not the case?
The head electrical engineer for the 747 was called out of retirement to work on the 787 project. He looked at what they had and told them it was not going to work. This I heard second hand from my good friend, his daughter.
It is not good enough to rely to such an extent on backup safety systems. They need to stop the fires from occurring, then we can feel comfortable in the knowledge that if something odd happens and a battery does catch fire, you’ll be alright.
If you keep the batteries from catching fire and you also have a fire suppression system, two systems have to fail in order for the plane to crash. (Okay, there are a lot more than two systems on the plane, but for the purposes of this scenario, we’re looking at two.)
If you don’t worry so much about the batteries catching fire because hey, there’s a fire suppression system, then only one system has to fail in order for the plane to crash. My understanding as a layperson is that after pretty much every air crash or even serious incident with an airplane, the problem is studied in detail and procedures, systems, or hardware is changed to make sure that such an incident cannot happen again. (If my understanding is incorrect I’m sure one of our aviation people will correct me.)
There are quite a few different sorts of batteries that use lithium. Some store more energy but are more unstable. Some are more stable, but don’t store as much energy or don’t release it as fast.
Casings for aviation lithium batteries are designed to retard fires. So it may be in one or another instance here a fire started and burned itself out, but was isolated enough not to set anything else on fire.
Damage to a battery can turn an otherwise safe battery into a bad situation. Some types of lithium batteries will burn or even explode if you punch a hole in them. Others will not. All will burn under some circumstances but one would hope that, for instance, no one is holding a blow torch to a lithium battery on an airliner.
So what sort of battery to use on an airplane is a trade-off between various characteristics.
So its all down to the batteries? What’s the weight advantage in a 110 tonne airplane (dry weight) by using Lion batteries rather than more well tested designs? Surely it can’t be more than 2 or 3 per cent. Which leads me to believe that the design brief was so biased towards weight saving that other considerations went out the window. Or has airliner design reached that point where a 1 or 2 per cent advantage become that vital?
All the routed hydraulics and pneumatics have been replaced by servos and electric pumps, because wires weigh less than pressure-bearing hoses and pipes. According to the wiki thing, “total available onboard power is 1.45MW”. Batteries provide a significant fraction of that, so that more engine power can be used for thrust, hence greater fuel efficiency and range.
I can’t quite envision why lithium ion batteries of sufficient size to cause sparks to fly when the Halon system operates would be used.
Perhaps for battery backup in case of power failure?
Are they actually part of the battery backup for the uninterruptible power supply (UPS)?
If so, I would assume that the casing/shielding/mounting systems would be designed with pretty efficient cooling during operation.
We recently ended a ban on lithium batteries being sent by mail in the US.
By all means ground the planes until cause effect and prevention can be assured.
That said, I hadn’t heard of in-flight issues, only on the ground which is when I would believe that the onboard UPS might actually be relied upon for certain maintenance/test functions.
Just a one cell Li battery in a pocket torch burned my thigh through my pocket when accidentally turned on.
Lithium batteries in discharge mode grow very hot, very fast. Anyone actually use a “laptop” on their laps
Judging by the wikipedia article the latest incident was in flight. The plane landed at the nearest airport because of high temperature readings in a battery compartment.
Yes, apparently this one (ANA) did not get to the point of actual fire inflight, but severe overheating to the point the casing broke and contents and fumes escaped. An airplane on the ground in Boston a few days earlier had an actual battery compartment fire detected after landing and deplaning.
Hopefully someone more knowledgeable than me will speak up…but I don’t believe they would rely on batteries for primary power during flight. Even if they did, the batteries would require recharging once they’re on the ground, and that energy has to come from somewhere, most probably the engines.
IANAAeronautical Engineer but it would seem to me reasonable it would go similarly to an automobile’s electrical system, where the system includes generators (in the engines) and batteries in line with each other and the batteries serve not just as starter/backup power but also as a way to stabilize and make constant the base load for essential functions, so the general load does affect the batteries anyway.