The MS-21, a new single aisle airliner produced by Russia's United Aircraft Corporation, is the first passenger plane borne aloft by lightweight carbon-composite wings built without a costly pressurized oven called an autoclave.
[...] Under the new technology, instead of using fiber that is pre-impregnated with resin, parts are made from a dry-fiber engineered textile which is placed in a mould and then infused with resin under a vacuum.
The parts can then be cured in an oven without pressure, a process estimated to cost 25 percent more than metal. Ultimately, that gap needs to narrow significantly or disappear.
Boatbuilders and windfarm makers have used this method for years. Secondary airplane parts have also been made that way.
But although Canada's Bombardier partly used the technique for its CSeries, it was rare for flight-critical parts before the designers of the new Russian plane chose it for the wing.
previous stories:
Irkut Shows New MC-21 Airliner
The Little Gear That Could Reshape the Jet Engine
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Pratt & Whitney's new PurePower Geared Turbofan aircraft engines are impressive beasts. Scheduled to enter commercial service before the end of the year, they burn 16 percent less fuel than today's best jet engines, Pratt says. They pollute less. They have fewer parts, which increases reliability. And they create up to 75 percent less noise on the ground, enabling carriers to pay lower noise fees and travel over some residential areas that are no-fly zones for regular planes.
Airbus, Bombardier, Embraer, Irkut, and Mitsubishi have certified the engines for use on their narrowbody craft. JetBlue, Lufthansa, Air New Zealand, Malaysia's Flymojo, and Japan Airlines are among the engine's 70 buyers in more than 30 countries. To people outside the aircraft business, what may be most remarkable about the engines is that they took almost 30 years to develop.
The PurePower GTF began to take shape in 1988, when Pratt staffers in East Hartford, Conn., including a 28-year-old engineer named Michael McCune, started developing a gizmo to slow the fan—the big rotating blades at the front of the engine that provide most of a jetliner's propulsion. For planes flying at typical speeds, a slow fan that moves large volumes of air at a moderate velocity is more efficient than a fast-spinning fan that accelerates a smaller volume of air. (The slow fan's also quieter.)
Russia's Irkut Corp. has shown, in its Irkutsk factory, the first completed MC-21 jetliner. It may be built in versions that carry about 130 to 211 passengers.
The company hopes to commence flight testing by the end of the year. As shown, the aircraft had a pair of Pratt & Whitney PurePower PW1400G-JM geared turbofan engines, but when manufacturing begins in earnest, it may be equipped with the Russian-built Aviadvigatel PD-14, which is still in testing.
The aircraft is scheduled to mark its first flight in 2017 and is planned be handed over to its first customers in 2019-20.
The МС-21 family includes two aircraft with a high degree of design commonality. МС-21-200 designed for 132 to 165 passengers and МС-21-300 designed for 163 to 211 passengers.
Coverage:
- Business Insider
- TASS (owned by Russian government)
- Air Transport World
- Aviation International News
- Sputnik News (sponsored by Russian government; has video)
- Defenseworld.net (Tor-friendly copy)
- ChannelNewsAsia
- Pravda.ru
(Score: 2) by richtopia on Wednesday May 31 2017, @04:59PM
The article has a bubble map with the range, seats, and number of orders for new narrow body planes. What is interesting is that it includes Bombadier and Embradier on the same chart as Airbus and Boeing. You can see the regional jet manufacturers still don't compete for number of seats per plane, but to consider them competitors starts to erode the duopoly that Airbus and Boeing have on medium range jets.
It will be interesting to see how the C919 and MS-21 compete. The existing players (Airbus and Boeing) already have a lot of experience and yet they still have been in court with each other over unfair government subsidies. That is not a market I would want to enter, but I suspect that the Chinese and Russian governments will be helping their respective manufacturers also.
(Score: 2) by DannyB on Wednesday May 31 2017, @05:55PM (2 children)
Please don't accuse me of looking at the article, but . . .
and
So how long does the fuel savings take to make up for the higher manufacture cost? How far into the aircraft's life?
Separate thought. Isn't aircraft life measured in 'cycles'? Would this material allow a larger number of cycles and thus a longer service life to recoup the higher manufacture cost?
Oh my. I don't know about cost, but aluminum takes a lot of energy to manufacture. So much so that it costs less to recycle and melt down aluminum rather than make more of it.
I'm assuming these composites would not be affected by gallium the same way that aluminum would be.
The anti vax hysteria didn't stop, it just died down.
(Score: 2, Insightful) by Anonymous Coward on Wednesday May 31 2017, @06:12PM
Carbon fiber also takes a great deal of energy to make, but don't have a comparison with aluminum. One advantage to aluminum is ease and low cost of recycling; I have not seen any effective methods for reclaiming carbon fibers from an epoxy-carbon composite.
As far as resin-transfer molding vs autoclave molding, it's hard to see how the low pressure process could possibly produce composite parts with the same compaction as a pressure autoclave. Compaction, minimum resin and maximum carbon, is historically the goal for high quality and minimum weight composite parts. Weight is super important on airplanes, any small weight savings means less fuel required for the life of the aircraft, which can be huge.
(Score: 0) by Anonymous Coward on Thursday June 01 2017, @10:11AM
So you mean it takes a lot of energy to smelt? It doesn't take much energy to manufacture.
(Score: 3, Interesting) by kaszz on Wednesday May 31 2017, @07:26PM (6 children)
If the material is hardened without heat there must be some other factor that initiate the process to make it hard. Just vacuum is unlikely to do that by itself. Something is missing in the description.
And then, will this material handle long term rough handling? burning sun, freezing cold, pressure cycling, bending, cracking, brittlement etc? are failure mode gradual or rapid and thus catastrophic?
How about Bisphenol-A a hormone disruptive poison? vapor pressure into the cabin?
Recycling?
(Score: 4, Informative) by Anonymous Coward on Wednesday May 31 2017, @08:32PM (3 children)
> If the material is hardened without heat
Epoxy resin (the most common binder used in carbon fiber composites) is a two part catalyzing reaction. Depending on the specific formulation, some varieties cure (harden) very slowly when cold. Typically the "pre-preg" material (carbon fiber and epoxy combined together) is stored in a refrigerator until use. Other formulations require a certain heating cycle to develop full strength. If the finished part is being designed for a high temperature application, then special epoxy or other high temp materials will be specified, and these may require a cure at even higher temperature.
(Score: 3, Interesting) by LoRdTAW on Wednesday May 31 2017, @10:59PM (1 child)
Adding to this, the vacuum is most likely there to remove air from the material to allow the resin to fill all voids ensuring no air pockets exist to weaken the finished product.
(Score: 3, Touché) by mhajicek on Wednesday May 31 2017, @11:30PM
That and to squeeze the fibers together so there are minimum voids for the resin to fill.
The spacelike surfaces of time foliations can have a cusp at the surface of discontinuity. - P. Hajicek
(Score: 1) by khallow on Thursday June 01 2017, @02:06AM
Slow curing can be used for a variety of complex tasks. For example, I did a project (roughly rectangular base for a movable robot, so I was told) where due to the complexity of the project, I used a slow cure epoxy combined with 35-40 F temperatures (crudely, 2-5 C) to put on a layer with some complex structure. It took almost two hours at a time to place the layer's various pieces and make sure they were properly wetted by hand. With most epoxy formulations the thing will start hardening 15 minutes to an hour into the process. Then I brought up the temperature of the piece (applied together with some vacuum bagging) to roughly 85 F (30 C) to cure it. The first layer went on like a dream, but I messed the second layer up (poor planning, ran out of plastic peel ply which is necessary for vacuum bagging so the part doesn't stick to what is soaking up excess resin).
An example more along the lines of AC's comment is the construction of the Orion spacecraft by Lockheed Martin (as prime contractor). As I understand it, the base structure is constructed of preformed carbon fiber parts and flaps which are then soaked in epoxy resin and refrigerated, prior to construction. I gather through a carefully choreographed construction process, the structure is carefully put together in a series of cold phases each followed by a phase where it is baked in an autoclave to harden the current state of construction. Perhaps someone with more knowledge of the construction of this process could describe it further?
(Score: 1) by Roger Murdock on Thursday June 01 2017, @03:46AM
FTS:
They're just using an oven to provide the heat rather than an autoclave. There's still pressure and heat involved, just from separate sources. Without reading the article I assume they're talking about Resin Transfer Molding, where the vacuum that the part is subjected to draws resin through the formed part. It seems to be a popular method in industrial settings now.
(Score: 2) by engblom on Thursday June 01 2017, @05:09AM
Unless I have got my information wrong, heat does not make it harder, it actually makes it more soft and elastic, thus less brittle.