Hacker News Reader

Comment by nullsandwich | Hacker News Reader

Currently, Boeing can not replace the 737 with a Carbon Fiber plane because there isn't enough Carbon Fiber produced on earth to keep up with the production line completing three aircraft a day. However, if enough Carbon Fibre could be created to logistically allow Boeing to move away from aluminum I am sure you would see a whole new level of demand for Carbon Fibre. Needless to say, the Carbon Fibre created would need to met Boeing spec, as Carbon Fibre does not have a single global quality standard, unlike aluminum (thank you WWII).

View on HN

The traditional carbon fiber production process uses polyacrylonitrile (PAN) and is very energy intensive. It is also slow.

There is a big push for new production processes / material sources.

Here's an example of technology using cheaper and less energy intensive acrylic instead: https://phys.org/news/2016-03-ornl-low-cost-carbon-fiber.htm... Or a plasma method making it from PAN but faster: https://www.youtube.com/watch?v=SLmU0BmLmFE

So there is potential for large drops in price and increases in supply in the future. Probably the wind energy market is driving this.

> Carbon Fibre does not have a single global quality standard, unlike aluminum

Carbon fibre also has many more degrees of freedom than aluminium. Not all of these degrees and their interactions, e.g. this arrangement of fibres with some other resin cured at that temperature, are well understood.

Why wouldn't Boeing make their own? They certainly have the money, the experience and the time to invest in such a technology if it is as critical to their success as you suggest.

Probably doesn't scale as well as aluminium; it'd be a lot more expensive to produce, as carbon fiber is very labor intensive. It's the same reason why Apple isn't likely to switch to ceramic phone bodies - the aluminimum milling facilities are already scaled up to extreme levels, with hundreds if not thousands of machines milling aluminium to keep up with demands.

see: http://atomicdelights.com/blog/why-your-next-iphone-wont-be-...

Boeing has a $6bn contract buying carbon fiber from Toray Industries, a Japanese company. I guess it's a tricky specialist process making the stuff. The 787 has 35 tons of fiber per plane and the 737 uses carbon fiber for the horizontal bit of the tail.

>> Why wouldn't Boeing make their own?

As this article points out, the new facility in Australia is state of the art. They claim it may produce better carbon fiber than anywhere else. So imagine Boeing made a massive investment in equipment to make their own, only to have someone come along and do better. They make airplanes and let the industry figure out how to make the fiber, that way they can always buy the best if they want to.

A complicated mix of Trade Secret, Patents, and Domain knowledge are the primary issues. I'm really hoping Boeing/Ford/GM/<big company that manufactures vehicles>/Tesla will buy out a couple of the manufacturers and then open the market up. Sadly because of the aforementioned this is unlikely to happen as it would trigger anti-trust concerns, and AFAIK almost all the best firms are privately held.

Simple because they don't want to. Even carbon fibers being a promise new business to invest, Boeing can just have a better ROI investing in something else.

> three aircraft a day

Is that the current production rate for 737s?

Not historically. While they have thousands on order, they seemed to have cranked out ~490 planes per year over the last 3 years, averaging 1.34 per day.

https://en.wikipedia.org/wiki/Boeing_737#Orders_and_deliveri...

Over 250 working days it's just under 2/day.

Does the 737 production line shut down on weekends? That would somewhat surprise me.

Nearly 2 a day at Renton: http://boeing.mediaroom.com/2014-10-02-Boeing-to-Increase-73...

It could be three airframes per day, but that doesn't necessarily mean three completed planes per day.

Why not? In what warehouse are the airframes being stockpiled while increasing numbers of them wait to be turned into completed frames?

Or are some significant fraction of airframes scrapped due to defects before the next stage?

I doubt that they are scrapping airframes. My previous statement wasn't accurate, and I understand why it would be questioned. I'd been conflating the airframe construction, part storage, and transfer times with the time it takes to complete a plane.

As an aside, here's an interesting article if you're interested in the process works (or worked at the time of publication): http://www.seattletimes.com/business/boeing-aerospace/boeing...

What kind and scale of impact (e.g. efficiency gain, design improvement, airfares) would happen if carbon fiber is widely used in planes?

I have absolutely no credentials what so ever...

My opinion though, if the strength is matched if not exceeded of a metal airframe, but weight is I don't know effectively halved or more... less fuel, farther flights, should be cheaper air fare, possibly less maintenance if carbon fibre doesn't have fatigue problems... but the cost.

Operating jets is all about opex, though. Airlines seem to be happy to plough billions into capex purchases as long as the long term total cost of ownership is good in terms of passenger miles.

Less gas is less gas, though! The long term cost is the real question.

As a cyclist, I have a perception of carbon as kinda fragile; take a good hit, and you really need to replace your fork. This makes me think the carbon will mainly be used for internal structure, which would still greatly reduce the weight of the plane (and this the base amount of fuel used), and bring down those lifetime costs. But if it's too fragile, then the overall lifespan of the plane is reduced, which would counterbalance the gains.

I had this impression for a long time as well, because it was true, but it may not be true any more. I can't pull it up right now (at work) but Santa Cruz did a great video comparing the strength of their carbon fiber frames to their aluminum frames, and in all scenarios carbon fiber frames proved the strongest. This included dropping weights on frames and forks, hitting them with hammers, etc... it changed my mind quite a bit about the resilience of carbon fiber.

The 787 is made from carbon fiber. That's what allows it to have higher cabin pressure and humidity.

Would it lower the fuel costs of the plane?

Yes. F1 car body is made of carbon fibre for lighter weight and strength. Fuel efficiency is very important in F1

In the F1 realm, improved fuel efficiency is a fringe benefit of lower weight, high-strength components. Low mass for improved acceleration, braking, and turning, as well as strength and stiffness for handling chassis and aerodynamic loads, are significantly more important than the tenths or hundredths of an mpg you get from not having to push the metal these parts would otherwise be made of around.

To respond to GP, if you can make an aerospace component lighter, once it's made, the thing the component goes on will be better than if it were heavy. Planes have to carry enough fuel to sustain altitude and also to push the plane to the destination. If the plane is lighter, you use less fuel to sustain altitude, saving money every moment the plane's in the air. If you can cut off enough weight, you can tweak the design of the plane itself because it won't need as much lift at speed, making it even more efficient (or faster per unit fuel burned).

Makes you wonder about the technologies that would evolve during WWIII..

Equally interesting to ponder what technologies are evolving because of our current situation

WW3 would have to last long enough for there to be any developments.

I'd certainly not bet any money on that happening.

Scrap metal recycling would have a boom.

If Einstein is to be believed, the main technologies to come out of WW3 will be sticks and stones.

I, for one, believe him.

carbon-fiber sticks and smart stones?

Well, we already saw the use of JDAM Cement in Libya.

I don't think he took into account that we could become an interplanetary species. WW3 could lead to death star style weaponry.

Encryption, for one. Distributed computing, for another.

If would be far more humane to hike taxes or cut financial aid funding and Medicare/Medicaid in order to pour massive amounts of money in staging giant televised robot prize fights over some atoll in the Pacific.

If by Aluminum, you mean Aluminium, then yes.

Reply on news.ycombinator.com