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International Civil Aviation Organization (ICAO) is building a carbon dioxide standard for aircraft emissions. The CO2 standard is planning to be carried out by 2016 as the aviation emissions airworthiness standards, which will immediately influences the aircraft airworthiness certification. In this paper, the main context of the carbon dioxide standard for aircraft, basis for the establishment and metrics were studied. In addition, the metric system, the key point of CO2 emissions standards, has also been explained. Moreover, the implementation and criteria of the metric system was presented through computing and analyzing of the active-duty models. As a result, the CO2 emissions standard is aiming at improve the fuel efficiency and operational efficiency, which effectively reduce carbon emissions.

Aircraft noise is the chief source of the airport and its peripheral areas. CCAR imposes restriction on specific categories of aircraft and requires more strict measurements of the noise. More scientific measurement method is required to meet the progressively tighter certification standards. Test noise procedures for transport category and turbojet airplanes are analyzed in this paper. The main aspects involved are: test sit requirements, aircraft flight path guidance, aircraft position determination, take off tests, lateral tests and approach tests.

According to the method described in Technical Manual of Aircraft Noise Evaluation Procedures, this system can predict the EPNL (Effective Perceived Noise Level) of aircraft take-off, approaching and side boundary. The system also contains the function of managing andcalling NPD database, and can assess the predictive value basing on the noise stringency curve. This saves a number of cost for the airworthiness certification of aircraft noise, and is a new engineering practice which has a good application value.

The data processing of static engine noise test, especially the elimination of ground reflection to access the free-field sound pressure level, has been defined as one of the basic steps in aircraft noise prediction on the noise certification procedure by ICAO[1,. Based on the importance of the method, this paper will study the impact of the ground reflection effects on the aircraft engine noise experimental, especially made a detailed overview for the calculation method of reflective index.This paper also gives the method of fixing this effect to get the free field sound pressure level, while making experiments to verify the feasibility of this method, so that make the noise analysis and prediction according to the noise certification procedures.

The ZK60 magnesium alloy plates were welded by laser beam welding (LBW) and the microstructures in the partially melted zone (PMZ) of welded joints were investigated. For the as-cast alloy, the eutectoid mixtures along grain boundaries (GBs) in the PMZ are liquefied during welding, and their re-solidified materials present hypoeutectic characters, which lead to more severe segregation of the Zn element along GBs, and thus enhance the cracking tendency of the PMZ. The main reasons for liquation cracking of PMZ are described as that the absence of liquid at the terminal stage of solidification leads to the occurrence of shrinkage cavities in PMZ, from which liquation cracking initiates, and propagates along the weakened GBs under the tensile stress originating from solidification shrinkage and thermal contraction. Lower heat input can reduce the cracking tendency, and the plastic processing such as rolling also contributes to the mitigation of PMZ liquation cracking by reducing the size of eutectoid phases and changing their distribution in the base metal.

The gear is widely used in aviation engines to transmit power. The gear faults affect somwhat the safety of the engines and aircafts. The vibration signal of gear is a carrier of gear situation information, it contains a lot of information about normal gear or faulty gear, so an effective signal process way is the important method of diagnosis the gear in good situation or not.The hybrid method of Wigner-Viller distribution (WVD) and singularity value decompositio(SVD) was introduced and applied to diagnose the gear faults in this paper. The results show that the hybrid method investigated is successfully to ascertain the gear fault.