Transcript Document
Used in construction on new technology aircraft and considerations in their use Péter Marosszéky FRAeS MIFA MAOPA (USA) Adjunct Senior Lecturer & Research Fellow University of New South Wales School of Aviation Faculty of Science 17/07/2015 New Technology composites 1 The areas that need to be considered: • • • • • • • • 17/07/2015 Occupational Health and Safety Advanced composites Damage tolerance and assessment Repair Assessments Repair schemes & processes Specialized equipment & tooling Approved MRO’s Training New Technology composites 2 Risks & hazards can be controlled • • • • • • 17/07/2015 Use of MSDS data A wide range of safety procedures have been developed and approved Current FAR 145.163 and EASA Advisory Circular 65-33 requirements High overheads & retraining Manufacturer programs ie: Boeing’s “Gold Care” program New Technology composites 3 A range of advanced composites in use on new generation aircraft • Two primary advanced composites are in use on the Boeing 787 and the Airbus A350XB • Boeing have opted for the Torayca 3900series highly toughened carbon fibrereinforced epoxy prepreg – unidirectional tape (various widths) & narrow slit tape (for fibre replacement) and woven fabric forms Majority of the 3900 – series made from intermediate modulus T800S fibre. 17/07/2015 New Technology composites 4 • Boeing continued: • The surface finishing provides resistance against moisture and contaminant ingress: Cytec SurfaceMaster 905. A high-temperature bisaleimide composite material, that allows application & removal of paint without compromising the integrity of the substructure • 17/07/2015 New Technology composites 5 17/07/2015 New Technology composites 6 • Other primary structures • Window frames & Engine Nacelles use Hexcel HexMC trademarked as HexPly AS4 carbon fibre prepreg (350°C/177°F cure) 8552 epoxy prepreg resin (Nordam) Wing & Trailing edge components use Hexcel’s HexFlow RTM6 with Cytec Surface Master 905 Some landing gear components utilize Hexcel IM-7 fibre. • • 17/07/2015 New Technology composites 7 • Primary structure: Empennage – Carbon fibre reinforced plastic (CFRP) • Fin leading edge – Glass fibre reinforced plastic (GFRP) • Radome – Quartz fibre reinforced plastic (QRFP) • Upper sections of fuselage – Glass reinforced Aluminium Laminate (GLARE) • 17/07/2015 New Technology composites 8 17/07/2015 New Technology composites 9 Airbus have selected the Hexcel HEXPLY M21E Carbon fibre toughened epoxy prepreg composite for primary structures 17/07/2015 New Technology composites 10 • • • Advanced composites have Significant weight, stiffness and strength advantages over Aluminium Advanced composites are susceptible to damage with greater resistance than Aluminium Advanced composites are susceptible to sunlight (infra-red) exposure, however pre-spun prepreg carbon fibre is less affected due to the tight weave reducing surface area of resins/catalysts 17/07/2015 New Technology composites 11 Boeing and Airbus tests have been validated by the ASTM Advanced Carbon fibre in use on the 787 and A350 has been certified to allow continued airworthiness if impact contact does not leave a visible sign, no further action need be taken If damage is visible then action must be taken in accordance with the respective SRM (Structural Repair Manual) • 17/07/2015 New Technology composites 12 An example of the effects of damage and subsequent fatigue propagation, tests have shown that in tight weave carbon fibre a breach of the structure not exceeding 2.54cm/1.0in. Will not propagate any further Larger areas of damage repaired and processed in accordance with manufacturer specifications will have permanent repair status. 17/07/2015 New Technology composites 13 Airbus research and assessment (validated by (ASTM) has shown the damage tolerance of GLARE is significantly better than Aluminium, however not as resistant Carbon fibre prepreg 17/07/2015 New Technology composites 14 Electrical and Fluid exposure damage. • • • • 17/07/2015 Electrical: Advanced Carbon composites are electrical conductors Copper mesh is embedded in the structure to provide for conductivity and earth return for electrical systems as the “earth return” New Technology composites 15 • • • • 17/07/2015 Fluid exposure: Coatings applied during manufacture provide protection against phosphate ester fluid (Hydraulic fluids) ingress Water and waste protection against ingress Corrosion is prevented by the use of Titanium fasteners New Technology composites 16 17/07/2015 New Technology composites 17 • Considerations of damage assessment • • • • • 17/07/2015 Area of damage Location Structural requirements Type of material Equipment and materials available at location New Technology composites 18 Repair must be in accordance with manufacturers SRM • • • • • 17/07/2015 Must consider: Proximity to major structural elements Aerodynamic cleanliness especially for RVSM and RNP factors Repair permanency New Technology composites 19 • • • Portable FTIR4100 Fourier Transform InfraRed (FTIR) spectroscopy to measure the effect of heat damage caused by lightning strikes, fire and engine exhaust • Olympus NDT35RDC hand held device check for possible impact damage include sub-surface damage BondMaster1000e multi-mode test device to check for disbonding & delaminations. OmniScan MX and Epoch 1000i using two similar ultrasonic phased array device to detect cracks, delaminations and inclusions 17/07/2015 New Technology composites 20 • • Most repairs envisaged for in-service will be conducted in-situ, manufacturers have designed specific repair schemes for the range of materials & structures MRO’s are developing processes for repair & maintenance of advanced composites eg; Lufthansa Technik AG has developed a method for the semi-automated repair of fibre composites, process uses scanning to within 1/100th of a millimetre using optical measurement techniques & computer controlled milling machine to create the bonded surface & perfectly matched precuts of individual composite layers. 17/07/2015 New Technology composites 21 Some of these include: The HEATCON HCS9200B Dual zone hot bonder • The HEATCON HCS9000B Single zone hot bonder • The HEATCON HCS2046-02 Phosphoric Acid Containment System (PACS) • A range of Composite Cutting Tools (CCT) for accurate and damage free machining & shaping • • 17/07/2015 New Technology composites 22 • Currently most MRO’s and airline MRO’s are gearing up for regulator & manufacturer accreditation • OEM’s also provide after market services for operators that do not have access to approved organizations. 17/07/2015 New Technology composites 23 There are a number of training organizations that provide Advanced Composite training in addition to OEM’s. This type of training is referred to as Advanced Skills training, requiring ongoing refresher training to retain qualifications and proficiency. A Part 145 organization must receive training from a Part 147 training organization. 17/07/2015 New Technology composites 24 Thank you 17/07/2015 New Technology composites 25