Hm seems still quite a bit noisier than airbus 350 (why isn't it mentioned even once in the article?)
Be careful about trying to judge the relative loudness of the two planes based on YouTube videos since the sound levels in the video will depend on the type (omnidirectional vs cardioid), frequency response of the mics, and location of the mics (distance from the plane, position relative to noise emitting components, etc) as well as how the video is mixed and other factors.
It's not mentioned because the planes are so different that there is little point in comparing them? A350 is 3x larger, has 2x the range, and is 4x the price. Seems to me that the use cases they've been designed for have to be completely different, and one can in no way be substituted with the other.
But the article does say that Airbus and Boeing each had a major project in recent years (A380 and 787) and they're unlikely to have anything major for the next decade. A350 sounds pretty major to me.
I wonder if Boeing and Airbus will increase the pace of new plane releases...
The A380 and B787 introductions were very rocky, with delays added to delays added to delays. On the other hand so far the testing of the A350 as been incredibly smooth.
I know that it's too early to draw any conclusion, and that the A350 is still one year from EIS. But when you take into account the actual competence of making a new plane, and how quickly it can be lost, I wouldn't be surprised if the lesson learned is that it is more economical for Airbus and Boeing to release new planes more often...
Well, the A350 has a long and painful history, it should have flown for years if customers had not threatened to boycott it. I can't see a fast release schedule, considering the price of developing a new plane.
You are right that Airbus had a hard time figuring out which plane to make, rushing a couple of A350 concepts before settling on the so called A350-XWB.
But once it was settled the engineering went smoothly. Or, should I say, has been going smoothly so far.
The skills involved in designing a plane are vastly different from that of figuring out which plane your customers will want 5 to 30 years from now.
The former Soviet Union also has a lot of airports that are too close to the city centre to handle noisy passenger air traffic. So there is a huge market in countries like Russia, Ukraine and Kazakhstan, all of which are spread out over great distances. In fact the ability to use a shorter than normal runway would make it possible for many of Siberia's towns to build an airport that could handle the Bombardier jets. And next door to Siberia is China which also has some considerable distances to deal with.
Does reduced noise necessarily mean increased efficiency? Short of using heavy sound deadening material, I'd imagine that reducing the noise in an aircraft means saving a lot of that previously noisy energy for useful work.
Your inclinations seem right. There is a positive correlation between friction (viscosity) and noise, and also between friction and energy waste. It is in part from that connection that reducing noise would boost efficiency.
I know this article is focused on noise, but the most important part about this engine is the efficiency. The fuel savings alone from having the high pressure section running at peak RPM in any situation is incredible. Billions and billions of dollars in fuel savings for a modern fleet.
Think of it as an orbital reduction gear more than a transmission that allows two different sections of the same axel to spin at differen speeds.
Checkout fuel burn vs. other engines. [1] The maintenance cost ratios across an entire fleet versus the fuel savings make it an absolute no brainer for regional fleets.
Source: My father a DER at MTU Aero Engines who developed the geared turbofan with Pratt & Whitney. DERs develop and sign off repairs in accordance with FAA regulations. He was also certified is EASA repairs.
That is correct. The short story here is the FAA simply can't keep up with the innovation so they certify a group of people that can certify a repair as safe, and effective. It can than be used, while the FAA eventually full approves the change. The DER assumes full responsibility for the repair, and it's safeness. There have been stressful Christmas eves when approving the duct taping of a loose part of a V2500 so a plane full of troops can make it home for Christmas. Don't worry, it was a single flight one direction approval (but it happens all the time)
they are not driving an axle or anything... are they?
They sure are, just not in the way internal combustion engines do. A turbofan is a turbine hooked up to a fan. The turbine does work by rotating a shaft, and the fan pushes extra air around it.
All engines have the potential to be maintenance / reliability nightmares. Over time we've learned how to make engines more efficient and more complex without failing often. This is just the next step - in a couple of decades, most passenger jets will have gearboxes.
The engine core (hot part) works best at a different speed than the fan part - fast and hot, vs slow and cool. hence they have a gearbox. But it's not like a cars gearbox, it has a single gear.
Aren't we talking about geared turbofans, as described in the article and http://en.wikipedia.org/wiki/Geared_turbofan ? Geared turbofans, unlike the ungeared GEnx, presumably have gears in gearboxes.
The person I replied to implied that all turbofan engines have gearboxes, that gearing was necessary to have the fan rotate at a slower speed than the "main engine". In reality, the vast majority of the turbofan engines currently used in commercial aviation do not have gearboxes. The engines referred to in the wikipedia article you cite are still in development or just entering production.
The wikipedia article explains the deets, but basically yes, the turbine at the back of the engine is connected to the fan at the front of the engine, and the compressor and whatnot, and the gearbox somewhat decouples the speed of the former and the latter. It would be a bit of a shame if said gearbox fails in flight, of course.
Without knowing a lot about geared turbofans, it would be cool to have a gearbox bypass such that if the gearbox fails, the engine could stop, engage the bypass, and restart in an emergency mode that's less efficient but gets thrust.
i know nothing about turbofans, geared or not, but i would guess that any kind of 'failure' of a gearing system at jet engine speeds means the entire thing is exploding, not just failing over to a backup system.
Large airliners are a big-money duopoly with a US incumbent. A single deal can make or break a project, or a company. I wonder how worried the Canadians are about industrial espionage by the NSA, as may have happened in Brazil and Germany.
I assume Canada is spied on, but Canada also appears to be an active spyer. Leaked NSA documents have revealed that Canada has been participating in industrial related spying on Brazil.
It's useful to note that Brazil is home to Bombardier's primary competitor, Embraer. The Canadian and Brazilian governments have both accused each other of subsidies in the aerospace market: http://en.wikipedia.org/wiki/Bombardier_Aerospace_and_Embrae...
I'll be interested in this when (ha) I hear that airlines are using that boosted efficiency to make coach seats more comfortable on the same profit margin, rather than continuing sardine-packing and pocketing the difference. Until then, it's entirely academic.
That stuff isn't new in passenger airlines? I was under the impression (and seemingly the vast majority of media coverage) that the majority of it has been introduced in the past few years with the A380 and 787. Is that wrong? What company do you work for that was making LCD cockpits for passenger airliners?
Argh, Bombardier make me angry! They're probably the main contender for showing how Canada still fails to understand the benefit of free market economics. The main problem here is all this stuff is essentially funded by things pulled out of the ground on the other side of the country, but rather than allowing the market to function you have a class of bureaucrats scratching each others backs in order to pass subsidies off to whoever bought them the best lunch last week or gave them a season ticket to the Canadiens.
That isn't to say there isn't a market for this kind of thing, but if there was really a market Bombardier could have done it properly, even via the stock market. Too much Canadian business is built around exploiting whatever the government is chucking around that week rather than being sustainable.
Whether other countries choose to subsidise development in a particular industry is irrelevant, and if they choose to essentially export their money then that's up to them. It's not like there aren't plenty of other things these people could be doing. If you reach the level of China style product dumping then you have a trade war situation and things are different, but that's not (quite) what is going on here, though if Boeing or Airbus gained a monopoly it would sure look like that.
What is really happening is risks are socialised, profits (if any) are privatised.
> What is really happening is risks are socialised, profits (if any) are privatised.
Well not quite, given companies pay tax too. Not only that, but large industries like Aerospace spend money on other stuff. I agree it's clumsy, but it isn't as simple as you put it.
Seems to me with the level of subsidy Boeing/Airbus/Bombardier receive, why aren't they just nationalised.
To add to this, aerospace companies contribute plenty to the economy, in jobs, scientific research - much more than most other corporations that are of a similar size.
And speaking as a Canadian, it's nice that we still do have Bombardier, otherwise those jobs would simply go down south (probably the actual talent too). Canada needs to invest in industries other than resources... And of course Bombardier IS profitable (forward P/E of 9.71 on the stock).
Do you seriously believe that the government subsidies of Airbus/EADS and Boeing in the 60s and 70s have been a net negative benefit to their home countries economic and employment wise, now that those two companies dominate the jet airliner market?
Well Porter as an airline is likely making a big bet on this for their downtown airport in Toronto so there is definitely a use-case there. I'm not sure if this is a contingency plan on their campaign to get the runway extended and noise by-laws lifted, but it sure seems like they're hedging their bets on this.
* Written from the downtown Toronto airport lounge.
Yes, as they rightly observe the plane does have uses, but if it really had enough, with potential customers to prove it, then they would have been able to get the development cash on the open market.
Gambling with other people's money is a lot easier than doing it with your own.
Speaking as a Canadian, I personally would rather funnel money into projects that keep Canadians employed. There is a rather difficult problem with competing against other larger nations in the west (especially our friendly neighbour) who too have large tax subsidies and grants.
Canada exports most of its oil refinery to the United States so it can double dip on taxes. It as a result employs Americans in the refineries. Should we stop subsidizing American jobs then?
The point is the government doesn't know where to best spend the money. Quite why it has so much to spend is the other question, especially in Quebec where there are other rather pressing needs.
I don't think many Canadians realise just how many non-Canadian workers they are subsidising as a result of all of this. There is the official logic of training locals in skills that get imported alongside government incentives, however, what seems to happen is you get a mobile group of people that just follow the incentives around from province to province.
One thing Bombardier do have in their favour is they are a local entity and the taxes on any profits do return to the system, so I can't fault them on that.
Most Canadians are aware of how Bombardier gets a large amounts of subsidiaries. Subsidisation is a large part of the Canadian economy so if you were to ask any alert person here if Bombardier was getting subsidised, it would range from "probably" to "yes".
I am not sure why you're angry unless you're Canadian yourself then I guess you're justified.
Subsidisation is a large part of the Canadian economy, primarily in provinces where the economy is a disaster area. They're not disaster areas that will be fixed by subsidisation; they're maintained and made worse by market distortions of this kind.
I'm angry because Canada would be far better off as a whole without this, and the parasitic bureaucracy that sucks the life out of the non-subsidised parts of the system.
> I don't think many Canadians realise just how many non-Canadian workers they are subsidising as a result of all of this.
The non-Canadian workers are still paying Canadian taxes - Quebec taxes, even. Quebec's government wants its population to grow fast, especially so when they're high-earners. The investment absolutely makes sense from that respect.
I think this a case where free market economics would not have produced the sort of improvements and innovations that we see with this new model. You need a lot of stability do pull this of over a long period of time. Stock market doesn't allow that.
Without subsidies, there would be no Bombardier. Is that what you would prefer? I'm not sure how it's irrelevant that competitors are receiving subsidies. If it's easier to build with other people's money, isn't that a prudent course?
Shouldn't there always be a manual flying mechanism failsafe in the case of electrical failure? Fly-By-Wire doesn't seem very safe to me... in the same way I have doubts about Drive-By-Wire.
The A320 (introduced in 1988) uses only fly-by-wire. There's been almost 6000 of them built since. The Boeing 777, 787, Airbus A330, A340, A380 and forthcoming A350 are all fly by wire. It's a proven technology which has millions of flight hours behind it.
To fly something the size of a modern airliner, you need assistance. Even if they all used traditional control systems you'd still need functioning hydraulics to control the aircraft. That's why we build lots of levels of redundancy into the system. Rather than making something which can gracefully degrade to manual control, we make something which is so failure resistant that it never loses power.
virtuz: It seems your account is dead. Not sure why - your comment history doesn't make it obvious. Maybe worth asking HN admins about?
Mechanical systems fail too. Cables can snap, gears can shear off, pedals can bend. As long as you require an appropriate level of redundancy, there's no reason an all-electronic plane should be any less safe.
In both of these cases, rapid decompression from a failure of the cargo door caused parts of the floor to collapse and sever or restrict the mechanical cables leading to the aft control surfaces of the plane. Although the American Airlines pilots were able to land the plane safely (they still had some control), the Turkish Airlines pilots were not so lucky.
Furthermore, even mechanical systems are assisted by hydraulics. Hydraulic systems can fail, usually through draining, leaving the flight uncontrollable. So to add to the comments by both lmm and leoedin, safety has no bearing on whether the aircraft is mechanically controlled or electronically. There are also deployable ram air turbines[1] that can provide a small amount of emergency backup power in the event of a total failure of all engines:
http://www.youtube.com/watch?v=h3AiGiJgf9Y
http://www.youtube.com/watch?v=_3SMaNrsaoI
But it's cool we got to see so many first flights this year!
Here is some detail on why it is so quiet
http://www.flightglobal.com/news/articles/airbus-a350-xwb-se...