以目标机场为初始目的地备降场的二次放行

对二次放行飞行计划时能否以最终目标机场做初始目标机场的备降场等问题进行了讨论,通过理论分析和实际计算证明:以最终目标机场做初始目标机场的备降场的二次放行,一般不能增加业载,而且会使业载减少.当以最终目标机场做初始目标机场的备降场时,如果在二次放行点的剩余油量少于正常情况的再次放行所需油量,但满足做无备降场的二次放行的油量和气象条件的要求,可以由二次放行点再次放行到最终目标机场.     

大面积航班备降时的现场运行指挥

<正>航班备降时,备降机场就是保证飞行安全的最后一环,接收航班备降是机场的责任和义务,做好备降航班的保障工作对于飞行安全具有重要意义。民航局通过下发《关于进一步加强备降航班保障工作的通知》对备降航班保障工作展开了整治并提出了具体指示。而备降航班的保障工作是一项复杂而系统的工作,需要航空公司、空管、机场等单位的通力协作。备降航班落地后,地面保障工作最重要也是最中心的一环无疑是机场的运行指挥中心,对于现场运行指挥人员来说,备降航班的顺利落地意味着保障工作的开始。下面以烟台这个中等规模旅游城市在旅游旺季大规模航班备降时的现场运行指挥为例,探讨大面积航班备降的现场运行指挥。     

A320飞机烟雾警告／故障分析

烟雾探测系统用以监控飞机上特定区域所出现的烟雾,这些烟雾往往是发生火情的征兆。飞机上出现烟雾虽不像火情那样紧急,但同样对飞行的安全危害极大,往往造成飞机的返航、备降甚至紧急撤离等,烟雾中所含的一氧化碳和一氧化二氮对机组和乘客是致命的,因此具备烟雾探测系统是飞机     

波音飞机与加程飞行

所谓“加程飞行”是指双发飞机在运营中,当一台发动机失灵需飞往备降机场时,能以其航班飞行中的一部分单发飞往60多分钟以外的备降机场。现在“加程飞行”已很普遍。当今各航空公司每月累积的“加程飞行”在1万多个航班以上,航线越过大西洋、加勒比海、印度洋、亚洲、塔斯曼海及西、南、中太平洋。 1953年颁布的“美国联邦航空条例”规定,双发飞机的运营航线离一个设施完备的机场,不得超过1小时的飞行距离。在当时,活塞发动机的过热一直是个大问题,所以这一规定曾是很有意义的。后来随着形势的变化,1小时的飞行改为2小时,现在有几种飞机/发动机的组合被允许作3小时的加程飞行。这样一来,远程直飞航线越来越多,大大提高了运营的可靠性和安全性。据统计,双发飞机运营成本要比3发或4发飞机的运营     

四发客机在超远程航线上显优势

长期以来，双发延程飞行（ETOPS）被认为是一种安全、经济的飞机运营人人。在跨越北大内洋以及城市密度大一些的短巾出航线上，由可供备降的机场比较多，双发客机受到灼影响还很小，只要与备降机场保持60分钟、gO分钟、12O分钟或最高为18O分钟的飞行距离即d。相比之下，在跨越太平洋和北极等越远程航线上，中于需要跨越备降机场比较少、自然条件比较恶劣的地【，四发客机就占据了优势。如果一台发动机在空中出现故障，四发客机可以依靠另外三架发动机继续飞往目的地，从而避免了客机必须备降所带来的经济损失，旅客的抱怨及对航空公司信…     

试飞备降机场评估与选择

针对试飞运行与民航运行的不同,就如何选择试飞备降机场进行分析与研究,并通过对某型飞机在试飞飞行组织实施保障中积累的工作经验的总结,结合民航签派放行关于备降机场的选择方法与民机试飞运行保障特点,提出了民机试飞备降机场保障条件评估方法与试飞备降机场选择方法,为提升试飞安全性及试飞运行FOC系统的建立奠定了基础。     

双发飞机延程飞行及发动机可靠性

双发飞机延程飞行的历史与现状早在1936年美国实施的联邦条例就要求飞机获得批准飞行以前,申请者要证实沿计划飞行航路每隔185公里至少有1个可以安全起飞和降落的备降机场,不管地形地域的情况如何。此条例限制了双发飞机飞行的航路,影响了双发飞机的飞行距离。 50年代初期,由于活塞式发动机故障率随着发动机马力增大而增高,这给双发飞机飞行安全带来了很大问题。为此,美国联邦航空局(FAA)     

航班备降的保障工作

在我国民航不断深化改革和运行总量不断攀升的背景下,航班备降保障工作中积累的问题也逐渐浮出水面。民航局对航班备降的保障工作极其重视,多次下发电报开展整治活动提出具体指示,并召开全国性民航会议进行专题研究。做好航班备降的保障工作对飞行安全有着非常重要的意义,这需要航空公司、机场和空管等单位通力合作、协调一致才能顺利完成。     

咸阳机场一次罕见天气突变的预报与保障分析

咸阳机场气象中心承担着机场及陕西飞行区域各类飞行的气象预报与服务保障工作，2001年12月6日早晨，一次罕见的大雾天气，使机场能见度发生突变，造成了12架次飞机返航或备降，严重影响了飞行的正常。本文就这一典型个例进行分析，探讨天气发生突变的原因，总结预报与保障的经验与教训。     

新疆地区首个RNP AR程序通过试飞验证

我国西部地形复杂，高原和山地较多，航空公司不仅需要选派特殊改装的飞机和经过严格训练的精英机组执行这些机场的飞行任务，还要承担大量起飞减载、返航、备降、取消航班等不正常航班所造成的经济损失。使用RNPAR程序可以使航空器有效绕开超高障碍物，缓解空域矛盾，很适于在地形复杂、气候多变的高原机场推广使用。     

Flight trajectory optimization of sun-tracking solar aircraft under the constraint of mission region

The optimal yawing angle of sun-tracking solar aircraft is tightly related to the solar azimuth angle, which results in a large arc flight path to dynamically track the sun position. However, the limited detection range of payload usually requires solar aircraft to loiter over areas of interest for persistent surveillance missions. The large arc sun-tracking flight may cause the target area on the ground to be outside the maximum coverage area of payload. The present study therefore develops an optimal flight control approach for planning the flight path of sun-tracking solar aircraft within a mission region. The proposed method enables sun-tracking solar aircraft to maintain the optimal yawing angle most of the time during daylight flight, except when the aircraft reverses its direction by turning flight. For a circular region with a mission radius of 50 km, the optimal flight trajectory and controls of an example Λ-shaped sun-tracking solar aircraft are investigated theoretically. Results demonstrate the effectiveness of the proposed approach to optimize the flight path of the sun-tracking aircraft under the given circular region while maximizing the battery input power. Furthermore, the effects of varying the mission radius on energy performance are explored numerically. It has been proved that both net energy and energy balance remain nearly constant as the radius constraint varies, which enables the solar aircraft to achieve perpetual flight at almost the same latitude as the large arc flight. The method and results presented in this paper can provide reference for the persistent operation of sun-tracking solar aircraft within specific mission areas.     

民机首飞空速校准问题研究

中国商飞试飞中心，上海 201323) ： 民机首飞空速校准问题直接影响首飞安全，得到了相关从业者的普遍重视，然而系统性的研究多局限于各公司内部。通过对首飞空速校准的意义进行总结，对拖锥法、伴飞法和GPS四边法等常见的首飞空速校准的方法进行系统性介绍，并基于实际工作经验给出了针对空速校准，在首飞准备、首飞任务设计、首飞安全保障以及首飞机组训练等方面的建议。此外，针对国内民机首飞的实际特点，提出了一种改进的GPS空速校准方法，给出了改进的GPS空速校准法的具体试飞方法、数据处理方法，对该方法的误差来源进行了分析，并将该方法与其他传统方法进行了对比。结果表明，该方法不需要专门的试飞动作和测试改装，可以节省宝贵的首飞时间，同时大大降低实施的难度，可供其它民机型号首飞工作参考。     

对歼八某型飞机机体改型的探讨

探讨歼八某型机体改型的可能性,使歼八某型机体由二代战机平台提升至三代战机平台.主要的改进有:飞行过载由7 g提升至8 g或更大,以提高飞行机动性能;作战半径由×××km提升至××××km以上;机翼下表面导弹挂点增加到8个.由于机体结构修改范同不大,因而,继承原歼八某型飞机已有可用成果,可以做到省力、省钱、省时,使歼八某型飞机在短时间内挤入第三代战机的行列.     

基于工程经验和层次分析的民机试飞周期影响因素分析及可行性建议

试飞取证是民机研制的重要环节,也是当前国内民机研制亟需补全的短板,过长的试飞周期将给民机研制成本带来极大压力,过度推迟的取证交付计划将会给民机产品的市场竞争力带来不利影响。 基于当前国内民机研制经验,总结民机试飞的类型和特点,对比分析已有国内外民机试飞周期数据,结合国内民机实际试飞过程和工程经验,识别出影响当前阶段国内民机试飞周期的主要因素,并基于层次分析法和实际试飞实施案例经验搭建了民机试飞周期影响因素评价分析模型,对各层级影响因素进行了定量分析,得出减少试飞科目可有效减少试飞周期的结论,并就优先级较高的具体影响因素提出了优化完善建议或可行性方案,给出了民机研发试飞管控建议和取得型号检查核准书( type inspection authorization,简称 TIA) 前试飞科目选取建议,供后续民机研制参考使用。     

基于贝叶斯网络的机场过站时间分析

航班延误是目前航空运输业发展所面临的一大难题。从航班延误链式波及反应的角度出发,将贝叶斯推理应用于航班过站时间的分析,分别建立实际航班数据的单机场和多机场过站时间贝叶斯网络模型。模型清晰呈现了机型类型、前航延误时间等因素对机场过站时间的影响以及首发延误等级、经停机场过站时间调整量等因素对末班延误的影响。通过从多角度对模型进行分析,结果表明发生前航延误时调整航班在机场的过站时间可以有效减少延误向下游机场的波及。     

Multipoint optimization on fuel efficiency in conceptual design of wide-body aircraft

Aircraft conceptual design optimizations that maximize the performance at a design condition (single-point) may result in designs with unsatisfying off-design performance. To further improve aircraft efficiency under actual flight operations, there is a need to consider multiple flight conditions (multipoint) in aircraft conceptual design and optimization. A new strategy for multipoint optimizations in aircraft conceptual design is proposed in this paper. A wide-body aircraft is taken as an example for both single-point and multipoint optimizations with the objective of maximizing the specific hourly productivity. Boeing 787-8 flight data was used in the multipoint optimization to reflect the true objective function. The results show that the optimal design from the multipoint optimization has a 7.72% total specific hourly productivity increase of entire flight missions compared with that of the baseline aircraft, while the increase in the total specific hourly productivity from the single-point optimal design is only 5.73%. The differences between the results of single-point and multipoint optimizations indicate that there is a good option to further improve aircraft efficiency by considering actual flight conditions in aircraft conceptual design and optimization.     

电动飞机气动焦点辨识及飞行试验研究

电动飞机作为未来绿色航空的发展方向,引起了各国的广泛关注。电动飞机大多采用大展弦比气动布局,在飞行中机翼弹性变形较大,风洞试验测试的焦点结果不能较好地反映实际飞行要求。为了确定轻型电动飞机的重心范围以及得到飞行中准确的焦点位置,以某型碳纤维复合材料电动飞机为例,建立定常直线平飞和定常盘旋机动飞行的数学模型;基于盘旋机动飞行试验获得测试数据,采用物理解算法辨识得到实际飞行的焦点,并与风洞试验测得的焦点位置进行对比。结果表明：盘旋机动飞行试验辨识的飞机焦点位置要比风洞试验的结果靠前;对于展弦比较大且采用大量复合材料的电动飞机而言,在飞行过程中实际焦点位置与风洞试验结果有一定的差距,采用物理解算法辨识得到的焦点位置更接近于实际状态。     

基于Cardinals三次样条曲线的航迹生成算法实现

根据军用飞机飞行参数记录系统提供的飞行数据, 提出了一种利用Cardinals三次样条曲线进行航迹生成的算法。经过对离散点航迹误差修正及样条曲线的讨论, 给出了实时计算任意时间点飞机质心位置的公式, 为开发可在普通PC机上运行的军用战机飞行过程再现软件, 提供了条件。     

On the stability of flexible aircraft

The problem of aircraft stability has been a subject of concern since the beginnings of flight. Traditionally, aircraft stability has been treated within the confines of two separate disciplines, namely, flight dynamics and aeroelasticity. Based on some recent developments in the dynamics and control of flexible aircraft, this investigation uses the system concept to provide a broader approach to aircraft stability in an attempt to bridge the gap between stability as understood in flight dynamics and stability as envisioned in aeroelasticity. To this end, stability is studied in the following four cases: 1) dynamics of whole flexible aircraft using the unified formulation, 2) flight dynamics of quasi-rigid aircraft (aircraft treated as rigid), 3) aeroelasticity of flexible components, such as cantilever wing, cantilever horizontal stabilizer, etc., and 4) aeroelasticity of restrained flexible aircraft (aircraft fixed to a point, hence, having no rigid body degrees of freedom). The paper also presents a method to address the stability of flexible aircraft when the compressibility correction factor is known only at some discrete Mach numbers.     

Experience in the use of computational aerodynamics to predict store release characteristics

In the early days, store separation tests were conducted in a hit or miss fashion—the stores would be dropped from the aircraft at gradually increasing speeds until the store came close to or sometimes actually hit the aircraft. In some cases, this led to loss of the aircraft, and made some test pilots reluctant to participate in store separation flight test programs.During the 1960's, the Captive Trajectory System (CTS) method for store separation wind tunnel testing was developed. The CTS provided a considerable improvement over the hit or miss method, and became widely used in aircraft/store integration programs prior to flight-testing. However, since fairly small-scale models had to be used in the wind tunnel tests, in many cases the wind tunnel predictions did not match the flight test results. No mechanism was then in place to resolve the wind tunnel/flight test discrepancies.During this same time frame Computational Fluid Dynamics (CFD) had finally matured to the point of providing a trajectory solution for a store in an aircraft flowfield. However, since the computational tools were necessarily (due to computer resource limitations) limited to linear techniques, and since most store separation problems occur at transonic speeds, these tools had limited application.Recent advances in computer resources have greatly improved the capability of CFD to predict store release characteristics. Instead of using linear or approximate schemes, time dependent Euler and Navier Stokes trajectories could be computed in a reasonable time frame.Three international CFD Challenges, held during the last decade of the 20th century, have shown that CFD can not only match wind tunnel test data, but also predict flight test trajectories for complex stores at transonic speeds. It appears that CFD has matured to the point that it can be usefully integrated into aircraft/store compatibility programs.