On the use of a steerable main landing gear for crosswind landing assistance
On the use of a steerable main landing gear for crosswind landing assistance
复制标题
论使用可转向主起落架进行侧风辅助着陆
DOI：
10.1007/s13272-014-0107-2
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发表时间：
2014
影响因子：
--
通讯作者：
Klaus
中科院分区：
文献类型：
--
作者：
D. Vechtel;Ute Marita Meissner;Klaus
几起侧风相关事件表明，在强风条件下着陆对飞行员来说可能具有挑战性，并可能对航空构成威胁，或至少导致飞行员工作量增加和/或操作不正常。对于运输机来说，逆风着陆的常用进场技术是所谓的机翼水平和迎风航向修正的斜向进场。这种技术要求飞机在着陆前与跑道对准，以保持起落架和轮胎的横向载荷尽可能低，并保持着陆后在地面上的可控性。德国航空航天中心飞行系统研究所采用了可操纵主起落架的想法，并开发了一种反风着陆辅助系统。在进近过程中，所有起落架支柱都自动与跑道对齐，因此不需要进行减速操纵。在地面上，辅助系统使用每个可操纵起落架、差动制动和空气动力控制面来控制和稳定飞机。着陆后，飞机自动与跑道中心线对齐，并且仍然存在的斜航角缓慢减小。为了评估这种着陆技术的好处，进行了一项模拟器研究，其中飞行员在回路中使用一种典型的中程运输机模型。研究结果表明，在强逆风条件下斜行着陆不仅可以改善飞机的操纵性，而且可以显著减小作用在起落架上的侧向力。研究还表明，使用可操纵主起落架能够扩大自动着陆操作的范围，目前在最大允许侧风方面，自动着陆操作相对有限。总之，该系统已被证明能够提高飞行安全性，降低由于复飞或改道而导致的与天气相关的延误风险，并且还减少了着陆和着陆期间起落架上的结构载荷。
Several crosswind-related incidents show that landing under heavy crosswind conditions can be challenging for pilots and may pose a threat to aviation or at least lead to higher pilot workload and/or irregularities in operations. For transport aircraft the common approach technique for crosswind landings is the so-called crabbed approach with wings level and a windward heading correction. This technique requires alignment of the aircraft with the runway prior to touchdown in order to keep lateral loads of the landing gear and tyres as low as possible and to maintain the controllability on ground after touchdown. The German Aerospace Center Institute of Flight Systems has used the idea of steerable main gears and developed a crosswind landing assistance system. During approach all gear struts are automatically aligned with the runway so that no decrab manoeuvre is required. On ground the assistance system uses each steerable landing gear, differential braking, and the aerodynamic control surfaces to control and stabilise the aircraft. After touchdown the aircraft is automatically aligned with the runway centreline and the still existing crab angle is slowly reduced. A simulator study with pilots in the loop using a model of a typical medium range transport aircraft was conducted in order to evaluate the benefits of such a landing technique. The study revealed that not only the aircraft controllability could be improved by landing in crabbed motion under strong crosswind conditions, but that the side forces acting on the landing gear can be reduced significantly as well. It was also shown that the use of steerable main landing gears is able to enlarge the spectrum of autoland operations, which is relatively limited at present in terms of maximum allowable crosswinds. All together the system has shown to be able to improve flight safety, lower the risk of weather-related delays due to go-arounds or diversions, and it also reduces structural loads on the landing gear during touchdown and landing.