Oops! it happened again......nut and bolt. yeah very little thing to hold two pieces together again slow down the production of deamliner. Itgonna be dream again for Boeing. This time not only fastener delayed their schedule, they are having trouble attachng structres.
In the most recent glitch, a pressurization test on a Dreamliner fuselage revealed a small gap under the heads of thousands of fasteners. The problem occurred on the floor grid and other structures installed inside the fuselage shell where titanium was fastened to carbon fiber composite. This means they have to replace thousands of fasteners. Currently 12 dreamlines are in production assembly. Earlier the productionof dreamlined was delayed because of fastener supplier. This time it is their design glitch. They didn't define the specification of attachingtitanium to the compoisite shell. The specifications were developed by Boeing engineering staff.
Here is the engineering description of fastener specificaton:Cadmium coatings are applied to ferrous and nonferrous metals to provide resistance to corrosion. Like zinc, cadmium also provides sacrificial protection to a substrate such as steel by being preferentially corroded when the coating is damaged and small areas of the substrate are exposed. Electroplating accounts for more than 90 percent of all cadmium used in coatings and is normally specified in thicknesses between 10 and 30 microns.Because of incorrect specification now some of the fasteners are not flush and some have gap between the structre and the head of the fastener.Beoing has stated the problem as"fastener with incorrect length"
Tuesday, December 16, 2008
New Fastener Glitches Slow the Dreamliner Again
Posted by Mechanical Sky at 10:19 PM
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