Purpose

The purpose of this paper is to present the result of simulations that were performed to assess the uncontrolled motion of the passenger aircraft following its wing tip was suddenly cut. Such a simulation can help to understand the tendencies of aircraft behaviour after wing tip cut, assess how fast this phenomenon is going on and estimate the values of angles of attack, sideslip and pitch angle basing on given aerodynamic characteristics. Also, answer the question if pilot can counteract high deviations from flight path initially planned during the final phase of approach to landing.

Design/methodology/approach

Simulation is based on the full non-linear equations of motion derived from generalised equations of change of momentum and moment of momentum of rigid body. Dynamic equations of motion in the so-called normal mode are solved in the so-called stability frame of reference.

Findings

It was found that asymmetric rolling moment must be compensated by essential increase of pitching moment. Moreover, it appeared that aircraft goes into high angles of attack and high pitch angle and, therefore, for reliable simulation, the available aerodynamic characteristics must include angles of attack till 90 degrees when total flow separation occurs.

Practical implications

For accurate simulation, it is strongly recommended to perform to perform first the wind tunnel testing in the range of +20o ÷ 120o and use it in flight simulation.

Originality/value

The presented methodology is an original for numerical simulation of flight trajectory during the final phase of approach to landing in a hazardous state of flight. For reliable simulation, the available aerodynamic characteristics must include angles of attack till 90 degrees when total flow separation occurs, whereas usually maximum angles of attack used in wind tunnel experiments for passenger aircraft are not higher than 25 degrees. The influence of limited range of experimental data on results of simulation is another value which can be adopted in the future investigations of hazardous states of flight.

中文翻译：

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带有翼尖切割的客机飞行模拟

目的

本文的目的是展示为评估客机翼尖突然切断后不受控制的运动而进行的模拟结果。这种模拟有助于了解翼尖切割后飞机行为的趋势，评估这种现象发生的速度，并根据给定的空气动力学特性估计迎角、侧滑和俯仰角的值。此外，请回答飞行员是否可以抵消在着陆进近的最后阶段与最初计划的飞行路径的高度偏差。

设计/方法/方法

模拟基于从刚体动量变化和动量矩的广义方程导出的完整非线性运动方程。所谓的正常模式下的动态运动方程在所谓的稳定参考系中求解。

发现

发现非对称横滚力矩必须通过俯仰力矩的基本增加来补偿。此外，似乎飞机进入大迎角和大俯仰角，因此，为了进行可靠的模拟，可用的空气动力学特性必须包括在发生全流分离时达到 90 度的迎角。

实际影响

为了精确模拟，强烈建议先在+20o÷120o范围内进行风洞测试，然后在飞行模拟中使用。

原创性/价值

所提出的方法是在危险飞行状态着陆的最后阶段对飞行轨迹进行数值模拟的原创方法。为了可靠的模拟，可用的空气动力学特性必须包括在发生全流分离时达到 90 度的迎角，而客机风洞实验中使用的最大迎角通常不高于 25 度。有限范围的实验数据对模拟结果的影响是未来飞行危险状态调查中可以采用的另一个价值。