Aerospace Engineering Online from ACE

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	Orbital drilling for delamination-free holes Sandwich constructions for space applications are typically made up of thin layers of carbon-fiber composite skins separated by an aluminum or carbon honeycomb core. A common and significant problem occurs when drilling such structures using conventional methods: delamination on the exit side of the composite layers. (read more)
	Reducing human errors in aircraft maintenance Simple, often procedural mistakes--rather than those concerned with technology--are responsible for many aircraft accidents and incidents. Maintenance human errors are of primary blame in about 6% of fatal accidents and about 15% are of contributory cause. Overall, operations errors are responsible for 70% of fatal accidents, according to John W. Saull of the International Federation of Airworthiness. (read more)
	Electromagnetic protection for life Aircraft electromagnetic protection has always focused on the design, test, and analysis required for certifying aircraft. However, this effort is now being expanded by engineers at Cessna Aircraft Co. to include the continued airworthiness of electromagnetic protection over the entire life of the aircraft. To do so, engineers will require a better understanding of the scope and magnitude of maintaining assurance over the lifetime of the aircraft. (read more)
	Keel beam design poses many engineering challenges for Airbus The A340 fuselage extension required by the -500/-600 project has created a considerable engineering and manufacturing challenge for Airbus. The extension required engineers to develop a new large keel beam, measuring 16 m in length. The keel beam provides rigidity in the fuselage center area where the landing gear is located. Due to weight and rigidity requirements, a design consisting of composite panels fastened together to form a beam of trapezoidal shape was chosen. Two beams are used on each aircraft. The level of loads to be transferred in the keel beam required the selection of fasteners with diameters above 10 mm. (read more)