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Comment by garretruh | Hacker News Reader

While I have enormous respect for Elon Musk, I would hope that Boeing engineers have just as thorough an understanding of the workings and safety implications of Lithium-ion batteries. Though Tesla's engineering is admittedly much more focused around battery technology, Boeing has decades of experience with aircraft electrical systems.

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I have enormous respect for Elon Musk, and he's right, large cells without thermal barriers between cells are dangerous.

Boeing doesn't have a "decade of experience" with Lithium-Ion batteries though. The particular type of batteries have an elevated risk profile, but are light weight. The 787 has a larger APU than previous aircraft, and requires a larger battery to start the APU.

These particular batteries are Lithium Cobalt Oxide. One of the sub-contractors, Securaplane, who made the battery controller/charger, had their factory destroyed by fire, after a battery malfunction in 2006.

Edit: Cessna had problems with their Lithium-Ion batteries in some Citations, and had to replace them with NiCADs in a emergency airworthiness directive.

It's not necessarily Boeing's engineers. A lot of the 787 design (not just fabrication) was subcontracted out, so it's just as likely to have been whatever subcontractor had the combination of low bid and business connections to win the contract.

Ref: http://www.newyorker.com/talk/financial/2013/02/04/130204ta_...

The 787 electrical design was subcontracted to Thales, who then subcontracted the battery work to GS Yuasa:

http://www.gsyuasa-lp.com/content/thales-selects-gs-yuasa-li...

I shouldn't be surprised if there aren't several people within Boeing with exactly the right expertise. Whether they were identified and listened to by management is a separate question.

If Musk is right (IANA Battery Guy), I would presume there are cost / design trade-offs involved. And some exec had to evaluate those against safety issues. Those are engineering decisions, they're also business decisions. If the execs deciding that didn't have the proper background to make an engineering evaluation himself, they are left trying to decide which engineers to trust. It isn't at all hard to see someone getting that wrong.

I'm an aeromechanical engineer, not an electrical one, but I suspect the fewer-cells design was chosen to save weight. Many unconventional design decisions in aerospace (everything with holes, novel materials which trickle down to cars and golf clubs) are driven by the need to reduce weight.

These systems replaced hydraulics for surface control, right? On a weight advantage? Making good on a decision like that is exactly what confirmation bias is all about.

The hydraulics are controlled exactly the same as any other fly by wire aircraft like the 777 or a modern airbus. The computer takes the pilot inputs and combines them with a flight computer that controls electric motors which move the flight surfaces with hydraulics.

The big increase in electrical supply (4x over the 777 i believe) is the result of the bleedless air architecture that boeing chose. There was a big push by boeing to make the system work as it was a selling point for the public and carriers. I think that decision didn't receive the scrutiny that it probably should have.

Yes, the situation you describe is not unlike the one at Morton Thiokol prior to the Challenger accident. You should look up the story of how Feynman (who was not an Aerospace engineer, gasp!) managed to bring the Challenger accident cause to light, despite some of the accident investigation committee's best efforts.

I'm sure Airbus engineers are also great with wing design, yet they recently had problems with the A380 wings because it was something new with which they didn't have as much experience. The same could be said about these advanced lithium-ion batteries, I believe.

It would appear that Boeing had a small oversight. Building a plane is not like building a car. There are different requirements. While some requirements overlap there are clear fundamental differences.

Now, with that said, it could be that SpaceX and Tesla were allowed to focus more on batteries while Boeing had to improve jet engine efficiency as well as electrical battery usage.

SpaceX and Tesla try to keep as much of this in-house as possible, so they can maintain full oversight and make changes without unnecessary cost overhead.

Boeing had 10 layers of contractors involved in this SNAFU. WWED = What Would Elon Do.

Pedantic: Boeing subcontracted the jet engine efficiency improvements to Rolls-Royce (Trent 1000) and GE (GEnx).

http://en.wikipedia.org/wiki/Rolls-Royce_Trent_1000

http://en.wikipedia.org/wiki/General_Electric_GEnx

In this case it is pretty pedantic I'm afraid. Engine subcontracting is pretty standard in aviation. Nearly all of the engine types I can think of are either GE or Rolls-Royce.

It's kind of like Rotax for motorcycles and Snowmobiles... give the designs or specifications to a supplier and have them do all of the heavy lifting.

no doubt Boeing know that even if the batteries smoke and fail they wont be a threat to safety, but Musk has a better handle on marketing. If there is smoke on a plane or car people expect the worst, regardless of if it is actually a safety issue.

I don't know, don't Li-ion batteries tend to fail fairly spectacularly? Those melted cars after Sandy come to mind.

From my limited experience with smoke in cars, sadly they often turn to fire. Because, you know, like the first humans that did create fire, very often when a fire starts there's smoke...

I've seen a Saab in which the ashtray started to smoke and then before we could pull out (on the highway) the dashboard had flames and started to melt.

And I've seen a very nice and shiny Porsche 911 Carrera model 964 whose alternator belt did broke and then started "burning" on the engine. We smelled it and then we could see smoke. By the time we opened the engine trunk (with our fire extinguisher in hand) it was on fire. Funnily enough the repair were under warranty and there wasn't much to change (the trunk needed to be repaint and one or two pieces changed).

When there is unexpected smoke on a plane it is a safety issue.

Seen that a Boeing supplier's factory went up in flames due to a battery that took fire, I'm not exactly sure there's "no doubt Boeing know that even if the batteries smoke and fail they won't be a threat to safety". Same for the 16 hybrid sport cars that burst into flames on that parking lot due to batteries shorting.

I think that: "There's no smoke without fire" may be the sentence you're after ; )

yes in a Petrol car there is a problem with smoke = fire. My whole point is that smoke in a petrol engine usually means something as either caught fire etc. Smoke in a Battery compartment may or may not.

Is it a safety issue? Probably, but not definitely. Do the general public have a problem with smoke on a plane? Hell yes.

Our experience with traditional cars and planes is that where there is smoke there is fire. That may or may not be true with the batteries, I dont know but I do know that Boeing do a LOT of testing, so would be suprised to see a plane go down due to these problems.

I believe the cars you were talking about were completely submerged in sea water and then caught fire. Presumably any car or plane submerged in sea water will get written off which is probably why they dont worry too much about it.

Li-ion fires tend to generate oxygen and so they are quite hard to put out. At 30,000 ft in the air I would consider this a fairly significant threat to safety.

Lot of shipping companies won't even handle Lithium batteries (over a certain size or quantity) on their flights.

FedEx's shipping guide, as an example: http://www.fedex.com/downloads/shared/packagingtips/battery_...

The batteries actually went up in flames though, it wasn't just smoke (I'm recalling the the adage about where there's smoke there's fire). The new flagship plane from Boeing wasn't grounded worldwide because there was no threat to safety.

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