PMA件的过去、现在与未来

<正>通过对PMA件市场的起步、发展和现状的简述,以及对市场背后本质因素的分析,预测了PMA件市场的未来发展趋势。在竞争激烈的飞机部件制造市场中,PMA件正在逐渐打破以往由OEM件垄断的局面,并占有一定的市场份额。在欧洲、亚洲、拉丁美洲和中东地区,PMA     

Lagrangian analysis of satellite-derived currents: Application to the North Western Mediterranean coastal dynamics

Optimal interpolation methods for improving the reconstruction of coastal dynamics from along-track satellite altimetry measurements have been recently developed over the North Western Mediterranean Sea. Maps of satellite-derived geostrophic current anomalies are generated using these methods, and added to different mean circulation fields in order to obtained absolute geostrophic currents. The resulting fields are then compared to standard AVISO products, and their accuracies are assessed with Lagrangian diagnostics. The trajectories of virtual particle clusters are simulated with a Lagrangian code either with new current fields or with the AVISO ones. The simulated trajectories are then compared to 16 in situ drifter trajectories to evaluate the performance of the different velocity fields. The comparisons show that the new current fields lead to better results than the AVISO one, especially over the shallow continental shelf of the Gulf of Lion. However, despite the use of innovative strategies, some altimetry limitations still persist in the coastal domain, where small scale processes remain sub-sampled by conventional altimetry coverage but will benefit from technological development in the near future. Some of the limitations of the Lagrangian diagnostics presently used are also analyzed, but dedicated studies will be required for future further investigations.     

关于复合材料修理标准化

随着波音787飞机和空客A350XWB等复合材料飞机的投入运营,许多运营商呼吁要实现复合材料培训认证的标准化。由OEM、运营商和管理当局组成的美国汽车工程师学会(SAE)民用飞机复合材料修理委员会(CACRC)自1991年以来     

合作与竞争

随着发动机可靠性的提高,发动机制造商(OEM)、航空公司和维修企业(MRO)之间的合作协议越来越多. 先进的技术使得制造商和维修企业的发动机变得更为可靠,与早期的发动机相比,返厂维修的次数明显地减少,而OEM与MRO之间的合作却越来越多.     

Confidence Limits for the Pointing Error of Gimbaled Sensors

The confidence limits for the pointing error of a gimbaled sensor relative to an off-gimbal reference are derived in this paper. The various misalignment angles and errors that lead to discrepancies between the indicated and the actual pointing direction are discussed in detail. A mathematical model is developed from which the statistics of the pointing error are derived. The confidence limits are obtained for a variety of cases.     

三维技术在维修领域的应用

航空维修业很早以前就了解三维技术,如用于计算机辅助设计与制造（CAD／CAM）的CATIA等软件创造了很多的奇迹。这些可视化软件过去多为设计师或工程师所使用,但近期将在维修工程的日常工作中得以应用。     

支线飞机的维修策略转变

支线飞机的维修模式正在发生改变,OEM的全面维修协议广受运营商青睐。     

怎样提高航线维修的效率

美国《大修与维修》（Ｏｖｅｒｈａｕｌ＆　Ｍａｉｎｔｅｎａｎｃｅ）是美国航空周刊集团出版社的，以报道飞机、发动机及机械电子设备维护维修的科技信息杂志，《航空工程与维修》是国际航空杂志社出版的一本集报道航空工程与维修为一体的刊物。自２００１年初开始，国际航空杂志社与美国航空周刊集团签订了版权交换协议，因此，我刊从本期开始，开设了Ｏｖｅｒｈａｕｌ＆Ｍａｉｎｔｅｎａｃｅ专栏，为广大中国民航军队的飞机维护维修人员提供了一个了解国外维修业的窗口，希望广大读者对本专栏提出宝贵意见，以帮助我们不断改进。     

Laser Ranging Capability as Affected by System Pointing Error

This paper discusses the interrelationships among the ranging capability of a laser ranging system, the beamwidth of the transmitter, and the system pointing error. Since, in general, the system pointing error is statistical, the probability of successful ranging can be determined by means of these interrelationships, as is illustrated in a detailed analysis of a laser ranging system in which a gimbaled mirror is employed as an optical relay.