COMAC C919

vincent

vincent

Grumpy Old Man
Staff member
Moderator - World Affairs
SinoSoldier said:
Did you read my previous posts? Boeing also sources much of its 737 components from overseas countries, but most of them are produced in factories operating under US-based companies. Additionally, the crucial parts of the aircraft (e.g. engine) could be sourced from US companies.

What the C919 represents, once again, is an exercise in human resource management, project leadership, and COMAC's first attempt at a major project (and a tough one at that). What the Chinese actually produced for the C919, they've been doing the same for Boeing/Airbus/etc. for years now. The C919 is not a technical marvel in this sense.

I'd like to see some sources for the 95% claim. The last time COMAC made a peep about their forthcoming projects, it seems that they were quite happy to get Russian assistance (no surprise there really).
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Guy, designing and building a complex product is not just "human resource management, project leadership". There are lots of engineering work involved. It's not just putting pieces together and expect the end result to work. One have to make sure each piece meet the specs and they fit with each other. Computer systems are able to communicate with each other. The hydraulic systems respond to the control system at the right time with the right amount of force and with the right duration. The sensors pass the right information in the correct format....
 
K

KIENCHIN

Junior Member
Registered Member
vincent said:
@SinoSoldier, you obviously haven't been involved in large engineering projects. In software development, developers don't write codes from the ground up. They generally use components and frameworks developed by others. I wouldn't not use an encryption scheme developed by some new grads. It is simply stupid to re-invent the wheel, especially there is a good chance the new wheel is worst than the existing ones. Look at the dependencies of open source softwares, they all have tons of dependencies

Since China wants to break into the aviation industry, it is simply STUPID for them to develop everything themselves because the amount of time and treasure involved. They made the wise choice of developing things they can do in a reasonable time and outsource the rest. COMAC is doing what in the software development world called the Agile methodology. One develops a workable product with added features one phase at a time
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Well said Vincent, why re-invent the wheel when it had already been invented, improve on it and move on to the next step, that's what I always say to my stubborn apprentices. Take the example of a certain country who attempted to do too much in building their first indegeniois fighter that had ended up being a FUBAR.
 
A

antiterror13

Brigadier
SinoSoldier said:
The original deal did include common technical features between C919 and CSeries, including (and not limited to) electrical systems, interface, flight deck (later dropped), and cockpit (later dropped). In fact, the list is probably a lot more expansive than what is mentioned here due to a lack of details on the deal.

I've no doubt that both COMAC and the public knows that the C919 is merely COMAC's baby steps in the aviation industry, for which it is important for the company to stand on the shoulders of giants. For the time being, the current C919 is no more than an exercise in management & project execution.

But for those heralding the C919's flight as a symbol of achievement for China's aerospace industry, it is hardly the case. Not one major subsystem was sourced from a Chinese company. Everything from the HUD to the powerplant have been imported and assembled.

The C919 is, merely put, a test run for COMAC's management and perhaps for its involved engineers. Its flight does not imply any sort of advancement, on the technical side, of China's aerospace industry.
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wowww, you are really disrespectful to thousands bright Chinese engineers who put together all pieces/puzzles tirelessly for months into C919. I am really wondering whether you have such experience in design?

It is really big achievement ...... I understand that it is no where near Boeing or Airbus (at least not yet)
 
Quickie

Quickie

Colonel
The body and wing of the aircraft are among if not the biggest components of the aircraft. Designing and building them would require years of aerodynamics study and testing on computers as well as in the wind tunnels.

Another thing is no manufacturer will sell you a ready-make airliner aircraft/wing design as they would the engines or the avionics. The whole thing about how they would design and build a new airliner is a trade secret that they would earnestly keep for the survival of the company.
 
N

nemo

Junior Member
SinoSoldier said:
But for those heralding the C919's flight as a symbol of achievement for China's aerospace industry, it is hardly the case. Not one major subsystem was sourced from a Chinese company. Everything from the HUD to the powerplant have been imported and assembled.
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The issue of subsystems is commercial expediency rather than technical reason. Everything that is on the aircraft need to be certified. And if you have a lot of vendors that need certification, that will delay the projects. Better get your aircraft certified first with subsystem already certified to reduce both technical and schedule risk, then replace the subsystems with domestic vendors incrementally.
 
J

JsCh

Junior Member
640

640

Link to weixin of AVIC's institute of aviation optoelectronic about their HUD used in C919 (in mandarin)
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Blackstone

Blackstone

Brigadier
MwRYum said:
Reminds me of the same bunch of whinners who dizz at MIC whenever the opportunity arises, and all I need to remind them is pointing at their iPhone, said "it still haven't blown your hands off, right?"

What if I remind you that China has been building components like vertical stabilizers for Boeing and Airbus for 30+ years? Or there's an A320 assembly line in Chongqing? How about a 737 assembly line planning for China (date for it coming online is unknown at this time)?

Simply put, C919 like everything else, has to start from somewhere. Project management, components and system integration are the key points this time, increasing domestically-produced components will be targets to attain in future production batches and successive projects, such as C929 and C939.

The key goal is as much as to produce a full aircraft as to build up an entire home-based production and supply chain. Think Samsung: they produce an entire smartphone as they OEM all aspects of hardware key to smartphone - battery (hmmm, dicey!), semiconductors, display/touchscreen, processors, solidstate memory chips, circuitry....now think about the supply chain for commercial aviation. It's not that different fundamentally. The said production cluster can equally compete for component supplyer status as they'd provide for their own home-grown industries. Market competition comes in many forms and levels.
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Maybe you mean something different in bold part of your message, but if COMAC's goal is what you described, then the C-919 is so far a failure since many of its most important subsystems are imported from other countries. More likely the 919 is continuing education to build on what COMAC learned making the ARJ-21. In other words, its the next important step in the 'journey of a thousand miles.'
 
Blackstone

Blackstone

Brigadier
vincent said:
Jesus, you really believe designing and building products are like putting Lego pieces together. Do you know how many components in an iPhones are actually designed and built by Apple itself? The answer is not a whole lot.(
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). Can you say Apple is just an assembler? Is Lenovo? Dell? HP?

There are plenty of engineering work in designing the body, wings, tail and other systems of the plane. There are the static test, wind tunnel test, flight test, passenger escape test, etc. Lots and lots engineering work. I'm sure getting the plane off the ground requires a lot of blood and tears. There is nothing wrong with applauding the achievement

COMAC is expected to increase the amount of domestic source to 95%. I!m sure they will succeed because of the government backing.
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Where did 95% come from? It sounds way too high, given previous posts in this very thread showing foreign suppliers for major subsystems and plane components.
 
Blackstone

Blackstone

Brigadier
antiterror13 said:
wowww, you are really disrespectful to thousands bright Chinese engineers who put together all pieces/puzzles tirelessly for months into C919. I am really wondering whether you have such experience in design?

It is really big achievement ...... I understand that it is no where near Boeing or Airbus (at least not yet)
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Agreed C-919 is a big achievement for COMAC and its many local (Chinese) suppliers, but what Sinosoldier said is essentially true and he or she doesn't need to be an aircraft and/or its subsystems designer to summarize publicly available information to form reasonable theories and conclusions.
 
Blackstone

Blackstone

Brigadier
nemo said:
The issue of subsystems is commercial expediency rather than technical reason. Everything that is on the aircraft need to be certified. And if you have a lot of vendors that need certification, that will delay the projects. Better get your aircraft certified first with subsystem already certified to reduce both technical and schedule risk, then replace the subsystems with domestic vendors incrementally.
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Nemo, your message sounds good, and it does look like that's COMAC's current objective. It also falsify some posters' claims of utilizing domestic supply chain for most of C-919's construction.
 
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