The great and safe accident that involves aviation glass nearly 10 years is few, these infrequent accidents refracted problem of aviation glass safety, what component of industry of boat of the countryman in also letting more person understand produces is short board
Global aviation glass is supplied basic by forestall of manufacturer of 3 big abroad. Graph / Xinhua News Agency
Aviation glass, the material that this one original little somebody pays close attention to, make social central point for a short while. On May 29, airliner of capital aviation JD421 is taking off before long late unripe mechanical failure returns to base, it is windscreen via checking outer vitreous craze. Before half month, sichuan airline (next weighing " plain boat " ) 3U8633 airliner is carrying out Chongqing - when Lhasa airliner task, cockpit is right before windscreen glass burst falls off, this airliner uses aircraft of model of empty guest A319.
After plain boat incident, chinese civil aviation bureau already was investigated to French aviation accident bureau (BEA) issue an announcement with empty customer firm, the law just will expedite professional technology personnel to come China the investigation that participates in incident works. Area of empty guest China to " finance and economics " the reporter expresses, according to civil aviation bureau and safety of law countryman boat investigation analyses the requirement of the bureau, airbus already the technical group with special assign, the investigation that is dominant of civil aviation bureau provides support.
Chief inspector of safety of civil aviation bureau holds Tang Weibin of director of aviation safety office concurrently to express, from eye antecedent condition looks, design, make, the respect such as craft is investigation direction.
For example the production methods of subassembly of the structural design of the plane, plane and aviation glass and process. Findings has not give heat, by associate with experience the likelihood needs last a period of time one year above, " finance and economics " reporter from be close to personage of accident board of inquiry to be in know, still did not eliminate any possibilities at present.
Outside dividing attention safety incident, aviation glass is supplied also become focal issue. Global aviation glass is at present basic by forestall of manufacturer of 3 big abroad.
A variety of likelihoods cause vitreous rupture
Aviation glass is the main component of the plane, rise not only transparent action, basically involve the function that maintains pressure boost of plane pneumatic appearance, cabin. According to installation position, it can divide the shipboard pane that is cockpit glass and cabin.
Before all aviation glass are applied by outfit machine, need to have a series of strict tests, must have fight bump, fight the function such as crackle.
To manage afore-mentioned functions, the windscreen glass of cockpit is needed by multilayer glass is combined and become. General hot toughened glass is the outerest, middle-level and lining are chemical aggrandizement glass, PVB is used between layer and layer (polyvinyl alcohol shrinks fourth aldehyde) or PU (polyurethane) or PVB+PU is united in wedlock together. Such design is to increase fight bump ability.
Windscreen glass needs to do tripartite face test and verify on structural intensity: (1) ultimate strength test and verify; (2) damaged safety test and verify; (3) fatigue test and verify.
A technologist that pursues job of plane windscreen glass tells " finance and economics " reporter, do not exceed 13700 meters type to designing moving height, windscreen glass serves as pressure cabin make a part, should bear quite the pressure that the biggest set is worth a powerful person of cockpit pressure release of 1.33 times; And consider the safety factor of 1.5 times, still need additional use coefficient the influence of the 2 function decline that will enclothe material function to be used fluctuantly, for a long time, ambient conditions. Accordingly, to prove the carrying capacity of this one maximum of windscreen, need is in 1.5 × of 1.33 × 2=4 pressure of cost of the biggest setting lays the pressure release a powerful person of times (the pressure tolerance upper limit that considers pressure release a powerful person) experiment assessment.
In addition, after windscreen glass itself produces an any damaged, requirement windscreen must can endure cockpit the carrying capacity of the biggest load that press difference and critical pneumatic pressure, consider the impact of temperature; Because this is the damaged safety ability that proves windscreen, need is in only the circumstance of a glass of relatively fragile whole structure layer leaves surplus, with cockpit the biggest use the 2 times load that difference presses after pressing difference and the biggest pneumatic to press poor overlay to undertake experimenting assessing.
Afore-mentioned experts express, in special risk, the bird that windscreen should prove to be carried so that stay in 1.8 kilograms is in what rate of cruise of the biggest sea level leaves the plane to bump, guarantee against is penetrable, and at least lining glass won't produce those who injure air man to fly off content.
Except prevent outside bumping, windscreen glass has the function of deice demist even. Accordingly, the outerest the inside of toughened glass still covers film of transparent electric conduction - heat film, this device is to help windscreen glass deice. Contain among lining glass demist device.
Will look according to afore-mentioned circumstances, aviation of the university that be the same as aid and navy of Shenyang of mechanical college professor tell " finance and economics " reporter, windscreen glass burst may be put in 4 big reasons. It is the exotic in high speed motion is bumped, for example bird, hail; 2 it is window frame and installation fastener problem; 3 it is vitreous quality problem; 4 it is to heat systematic breakdown.
According to the case that the civil aviation bureau reports, airliner of plain boat 3U8633 is come in normal climb when 9800 meters of headroom, cockpit is right before windscreen glass is abrupt burst falls off. 9800 meters of height are close to Yu Ping to shed a layer, shen Haijun expresses, in such height, existence flyer, hail is exterior the possibility that strikes thing is very small.
But this possibility still cannot eliminate completely at present, afore-mentioned windscreen glass experts to " finance and economics " the reporter expresses, chengdu - Lhasa course crosses headroom bird to bump with respect to Ceng Fasheng.
Window frame and installation fastener issue exist possibly also. This expert introduces, because plain boat incident is medium, in good condition reservation is in windscreen window frame, pressing plate, fastener former position, have no the evidence of blemish of any window frame, fastener. "Possible reason is to be in installation process, design a requirement without what install completely according to windscreen, bring about windscreen glass to have thereby taller force to assemble stress, caused the local loss of windscreen glass possibly. The plane is in long-term flight process, encounter some the higher load that press difference, flight load and force to assemble stress combination, exceed burst intensity to produce sudden burst so, loss of exhaustion of place of initiative perhaps blemish is accumulated, bring about sudden burst finally. Bring about sudden burst finally..
As we have learned, the west side wind that airliner of plain boat 3U8633 falls off blocks glass to be installed formerly for this machine, before throwing operation to the accident, have no any out of service record. If fall off this,investigation hind belongs to installation problem truly, so accident responsibility ascribes to probably center of empty guest general assembly.
Vitreous quality problem also nots allow to ignore. Appear this the plane of the accident is empty guest 319 model plane, belong to series of empty guest A320, 2011 consign plain boat. If leave factory when existence flaw, in the flight of year in year out, because exhaustion is laden,cause flaw occurrence problem possibly also.
The windscreen glass of airliner of plain boat 3U8633 is produced by group of class of French emperor dagger. Holy dagger class (China) respect of investment limited company tells " finance and economics " reporter, this is very infrequent accident. Chinese civil aviation bureau already organized a related side to launch investigation, before formal findings is released, inconvenience accepts any interviewing.
Heat whether is the system put in breakdown, it is investigation key likewise. Added among windscreen glass heat film, if heat systematic breakdown, the likelihood puts in local short circuit, electric arc (note: Phenomenon of a kind of gas discharge, have very big destruction to touching a head not only action, and make the time of open circuit is lengthened) problem, cause rupture of plane windscreen glass then.
This one problem Yi Youxian exemple. In October 2013, chinese civil aviation bureau ever released comfortable boat to dictate, the requirement is checked and change the windscreen of fixed window heats contact. Instruction of CAD2012-MULT-02R1 comfortable boat points out, person of a few operation reports, in cruise phase discovery the cockpit since number appears scorch odour and (or) the circumstance of occurrence aerosol. Investigate discovery, the windscreen connect that the reason of these incident is production of company of holy dagger class extreme piece scorchs. Involve relevant type of A330 and A340.
Afore-mentioned windscreen glass technologists express, air man to when changing cockpit glass has speech right more. If appear,slight cut perhaps wears away, after be being checked by manual, affirm accord with the condition that continues to use, personnel of the air man, discharged that sign a school does not ask to change likely glass. Usually, the service life of cockpit glass can amount to 10 years.
Cabin porthole glass, have the laden capacity of such high strength than doing not have the glass of cockpit, but have likewise fight the function such as pressure, and it is double deck glass commonly. Before accident of cracked of much pane having board, mostly by outside content is bumped and cause.
The investigation method of flower boat accident
There also is precedent of similar aviation glass accident on the history, most of well known is 1990 the accident that British airline produces. The findings after two years shows advocate because be maintenance,manage not to be pooh-poohed.
Airliner of British airline BAC1-11 5390 took off from Birmingham International Airport 7:20 in the morning on June 10, 1990, fly to Spanish Ma La to add. In British Oxfordshire Didekete in the sky 17300 feet of place, the windscreen burst of aircraft nose left falls off, pilot by epispastic window outside, hang in the side outside airframe, 3 panic-stricken sky inside cockpit take personnel to holding his double leg in the arms. Be in finally pair of driving operation below, the plane descended successfully in airport of the An Pudui austral England 7:55.
After accident happening, office of investigation of British aviation accident combines other and relevant section (institute of aeromedicine of place of air traffic control, civil aviation bureau, royal air force) compositive accident board of inquiry, to staff of airliner information, unit, plane communication of condition of damage, weather, plane is mixed the information such as pathology of record equipment, medical treatment undertook be checkupped in the round, it is investigation key and method below.
Board of inquiry had imitate test and research above all, the fixed bolt norms that goes up to windscreen glass, size, area undertakes detecting, examined to repair the screwdriver of windscreen glass.
Undertook checkup to the airworthiness attestation of the plane next, content includes: The model of BAC One-Eleven plane is eligible, the demand that the plane maintains, airline quality standard, maintain engineer license, company authorization, maintain manual.
Undertook examining to the infrastructure of British airline again, the administrative role from inside airline quality supervisory system, quality supervisory system, quality examines process, maintenance to control program, ground service to report content had thorough investigation.
Investigated British airline to be organized in the management of Birmingham finally, program of the facilities facilities of the responsibility that includes a tissue, organization, air terminal, inventory government, quality makes sure practice grooms, the E1022 program that Birmingham uses.
Last a period of time of board of inquiry completes investigation two years. British civil aviation bureau to " finance and economics " the findings report that the reporter provides shows, ying Hang ever changed before 5390 flights have an accident 27 hours windscreen glass. Investigate a discovery, in installing 90 screw in windscreen glass, 84 diameter is 0.026 inches (1 millimeter) , what should compare a level is small; 6 length of the others are 0.1 inches (3 millimeter) , what compare a level is short, add the effect that is reduced by the atmospheric pressure inside cabin, what bring about glass finally is broken fall off.
The member that investigate discloses, the engineer of British maintenance division is measured because of working load at that time big, when picking a part much with naked eye experience " as far as possible similar " for criterion, and the maintenance record that does not have referenced plane and storehouse provide personnel opinion, bring about accident happening.
Besides afore-mentioned immediate causes, british civil aviation bureau thinks to still have remote cause. Board of inquiry thinks, the security that maintains the job fails to get height takes seriously, because secure the quality of bolt to be in charge of by a person only, and after fittings is installed, fly directly, check without the course.
Manager of maintenance of plane in rotation is installed in windscreen glass nurse in the process not good at, existence is undesirable trade behavior, inobservant company level and use improper device, affected the quality of maintenance and the judgement to breakdown. And management department of British airline place, the trade catalogue that did not monitor in rotation to maintain a manager to use and quality audit do not accord with a standard, because they do not have the job of manager of maintenance of direct monitoring in rotation.
3 tycoons hold the market
These infrequent accidents refracted problem of aviation glass safety, what component of industry of boat of the countryman in also letting more person understand produces is short board.
Global aviation glass is supplied basic by forestall of manufacturer of 3 big abroad, the GKN company of the group of holy dagger class that is France respectively, England (LSE: GKN) and American PPG company (NYSE: PPG) .
The Shenggebansuli below division of group of holy dagger class company (Saint-Gobain Sully) hold the position of aviation glass to produce the job. Its are in 50 old the aerostat such as plane of a trunk plane that is the whole world, jet aircraft, branch line, helicopter, battleplan offers glasswork.
The Yierkute that the main client of company of holy dagger Ban Suli is empty customer firm and Russia aircraft company. Familial, A330, A340, A380 and Yierkute's MS21 all use empty guest A320 the aviation glass that Shenggebansheng produces. China also is holy dagger class Wu of one great undertaking develops the land. According to " finance and economics " reporter understanding, the III that holy dagger class is Chinese Shang Fei kind supplier, chinese business flies to what ARJ21 model plane of production uses is the aviation glass that Shenggebansheng produces.
British GKN company is European mainland glass of another big aviation produces a tycoon. The GKN Aerospace business below GKN banner distributings to be mixed at Europe the United States. The product basically involves aviation construction, push system and aviation glass. At present the client has GKN company Boeing, empty guest and business of operation of much home plane.
The American PPG company in 3 tycoons was Ford Tri-Motor plane to provide a window 1927. After this offers vitreous face plate for the army all the time. At present industry of empty guest, Boeing, Ba Hang and Pang Badi this whole world the client that manufacturer of 4 big aircrafts is PPG company.
Aircraft industry of China also is growing quickly in, drive downstream industry catenary necessarily rise abruptly. But the field is produced in aviation glass, still do not have occurrence breakthrough.
relatively wait for glasswork at automobile glass, difficulty of aviation glass production is extremely tall. GKN company side tells " finance and economics " reporter, the technical camp of aviation glass basically depends on how making sure diaphaneity asks. Need of plane windscreen glass undertakes lamination in very clean environment, in order to ensure the smallest optical blemish. In addition, aviation glass figuration also is a distinctive technology, need room of special oven, vacuum, and the tool such as 5 axes machine.
Be based on the existence of afore-mentioned technical camp, glass of whole world aviation produces can be counted on one's fingers.
Zang Shuguang of assistant dean of academy of science of glass of total courtyard of research of science of Chinese housing materials is being accepted " finance and economics " when the reporter is interviewed, express, this courtyard is in on 50 time can produce the century aviation glass, chinese boat also can produce aviation glass below hair banner 621 times. The military plan at that time and carry the 7 aviation glass that wait for civilian machine to all use two afore-mentioned units to produce.
However as a result of China the twists and turns of civilian engine facilities, civil aviation glass produces business to lack actual application experience all the time.
Foreign plane produces business to won't come to China choose a vendor, ordinary draw on local resources. Mainer is, civil aviation glass involves the issue of comfortable boat attestation, foreign supplier has passed American confederative Air Safety Board or the attestation of European Air Safety Board, the Chinese glass that without afore-mentioned orgnaizations comfortable boat attestation crosses produces business, cannot enter the supplier list of international tycoon.
Zang Shuguang thinks, if domestic civilian machine uses homebred aviation glass, pass comfortable boat attestation, business of production of Chinese aviation glass can infiltrate the market.
Above all, the plane designs an unit to should give vitreous business technology the demand, vitreous business offers design program and make appearance. Complete all sorts of tests and assessment next. Test-fly conclusion is obtained after holding plane trial flight. Vitreous business is OK alone or obtain comfortable boat evidence along with the plane. Obtain comfortable boat branch to approbate, after issueing letter, outfit of this product ability arrives on corresponding type. Branch of comfortable in the process boat all should intervene ahead of schedule.
Nevertheless, national engine facilities just starts afresh in, taller to the dependability requirement of each components. Lack of Chinese aviation glass carries out experience, dependability respect comes without enough data confirm, accordingly, the glass of civil aircraft supplies the country to still come from foreign tycoon in.
In recent years, what boat industry standard falls in is medium Hang Sanxin Inc. (002163.SZ, say below " in Hang Sanxin " ) make special type glass production is new army. Those who held water 1995 is medium glass of project of wall of deep treatment of glass of special type of development of Hang Sanxin key and technology, act and airport of be open to navigation or air traffic, smooth hot season and project of smooth hot season 3 big industries.
According to " Hainan daily " report, the boat in the Hainan that Hang Sanxin banner issues in is special the Hainan of settle of base of high-end glass production of Bo data limited company. First phase produces base to always cover an area of a face to accumulate 641 mus, share 4 product line that are regarded as to save priority discipline.
Among them, a line is electronic chip vitreous product line transforms a project, 2 lines transform a project to transcend product line of glass of TCO of white solar energy, 3 lines produce online Low-E plated film for complete oxygen combustion energy-saving glass product line, 4 lines are aviation and product line of tall iron glass, all produce 600 tons big project for day.
The aviation glass that the Hang Sanxin in developing C919 prototype of production to ever was used independently produces China. Hang Sanxin respect expresses in, have not form dimensions up to now, follow-up order affirms further in. Many personage inside civil aviaton course of study looks, prototype cannot be used on behalf of final business, chinese aviation glass produces actual strength to remain to rise.
Machine of the countryman in relying on is produced, the hopeful of Chinese component enterprise such as aviation glass breaks the monopoly of Euramerican company, but should master the most advanced technology and equipment, way is long still. Zang Shuguang expresses, civilian aircraft manufacturer can let aviation glass produce business as a child make, accumulate experience, progressively education expands the confidence of pair of homebred products, just expand next industry.
