飞机积冰及其英文译文

飞机积冰在飞行中冰是个坏消息。

它破坏了空气的畅通，增加阻力，同时减少了机翼所产生的升力。

结冰对飞机重量的影响与它对气流的干扰相比是微不足道的。

随着油门增加，抬高机头弥补阻力带来的升力损失，攻角增加，造成机翼和机身底部积累更多的冰。

结冰会发生在飞机的所有暴露面，不仅仅是对翅膀，螺旋桨和挡风玻璃，而且天线，通风口，进水口和整流罩都会受到影响。

它通常产生于在飞行中如无发热的地方。

它能够引起天线震动，造成断裂。

在中度至重度的结冰条件下，小型飞机结冰将变得非常容易，因此继续飞行是不可能的。

飞机可能会在比平常更高的速度或者更低的攻角失速。

它使飞机在俯仰和滚动上面失控，并可能无法恢复。

结冰也肯能使汽化器冻结致使发动机停止，或在一个燃油喷射发动机的情况下，挡住了发动机的气源。

冰种和飞行及其影响结构冰这种东西，会凝固在飞机外面。

它被描述为霜，明冰（有时称为釉冰），和混合冰。

雾凇粗糙，外观呈乳白色，一般附着在表面的轮廓。

大部分可除去除冰或防冰设备都可预防。

明（或釉）冰有时是清晰流畅，但通常含有一些气泡，或块状，半透明的外观效果。

积冰越大，越符合机翼形状，其形状往往是由上，下为特点清除冰密集，更难，比雾凇冰更加透明，并且像“牛角”。

一般很难打破。

（冲击力越大的地方，机翼上的结冰就越少；这种形状像是上下两端凸起中间下凹的角。

明冰密度更大，更坚硬比雾凇更透明，通常也很难去除。

）混合冰是雾凇和明冰的组合。

冰可以在机翼表面空气流动扭曲，减少机翼的最大升力，降低了最大升力攻角，影响飞机的操纵品质，在风洞测试中表明，霜，雪，冰（在前沿或机翼上表面），厚度不超过一粗砂纸片可减少百分之三十升力和增加阻力高达百分之四十。

较大的附着，更会减少升力，可以增加百分之八十以上的阻力。

即使飞机进入结冰条件下飞行配备除冰系统，未受保护区域依然会有冰的积累。

美国航天局研究显示，近百分之三十的阻力依然存在即使已经对飞机的主要表面进行清理。

非保护表面可能包括天线，襟翼铰链，控制喇叭，机身前部区域，挡风玻璃刮水器，机翼支柱，固定起落架等。

不幸的是，一些粗心的飞行员们，遇到严重结冰的时候措手不及，并且没有相应的计划。

许多飞行员只从天气简报中的信息来确定哪些地方不容易结冰，哪些地方可能会出现结冰。

然而，飞行员可以学到足够的基本气象了解那里的冰可能会得到他们的等待。

飞行员可以在离开地面之前制定一些防冰除冰的飞行计划。

结冰飞机表面可以形成在0摄氏度（华氏32度）或更冷时液态水存在。

即使是最好的飞行计划也有一些变数。

虽然这是相当容易预测的地方结冰潜力的大面积存在，具体结冰地区和高度准确的预测会带来更多的困惑。

山，水，风，温度，湿度和大气压力在对这些决策方面都充当着重要的角色。

所有的云都不尽相同。

有干，湿云。

云干水分，相对较少，因此，对飞机结冰潜力低。

北达科他州，因为它非常寒冷的冬天，往往是干云。

然而，在宾夕法尼亚州和纽约的冬天往往会带来阿巴拉契亚山脉与冷空气和大量的湿云及大量水分，当温度冻结或以下，与冰加载。

大湖是一个非常大的水汽来源。

一个寒冷的空气质量的起源是多少过冷云水将进行的关键。

如果盛行风携带超过水云，他们可能会被淋湿了。

以上图表显示了潜在的高冰的一些领域。

结冰状况有时可能会出现在地图上显示的上述低风险地区。

锋面和低气压的地区是主要结冰的区域，但隔离空气充足的水分质量不稳定可以产生足够的结冰云，使轻型飞机无法通过。

冻雨和小雨是飞行中最大的敌人，可以大大粗糙飞机机翼表面积大的区域或扭曲机翼形状，这是对飞行非常危险的，即使在短短的几分钟内。

冻雨发生时，从高空暖空气降水通过将低于冷空气逆温层下面。

较大的水滴可能会在没有除冰加热的后方部位冻结。

随着一道冷锋，冷空气下温暖的空气，解除在潮湿的积云形成更加迅速和由此产生的。

沿着暖锋，温暖的空气往往滑过较冷的空气，有利于形成层云结冰。

当你接近前，云层建立非常迅速，层与层之间纯净的空气也会迅速消失。

冻雨和冰冻毛毛雨，包括冻结小雨升空，有时出现在锋面附近。

如果您选择它通过前，请确保它不包含冻雨或冻结小雨和其他有害，如天气条件嵌入式（隐藏）雷暴。

你应该计划飞行通过前最短的路线，而不是在锋面附近久留。

结构冰如何迅速采集冰表面上取决于其形状的一部分。

薄冰现代化的机翼将更加比厚的冰还要影响大，旧飞机的机翼尾部表面通常会结冰速度远远超过了翅膀。

如果尾部失速是由于冰和它引起的气流干扰，在低海拔处改出的可能性不大。

有许多运货飞机由于尾部失速而失事。

同时也发生在很多轻型飞机，但通常是没有很好的记载。

对于尾失速不太熟悉的许多飞行员，需要强调的是，机翼失速威胁更大，这是非常重要的正确区分这两个，因为所需采取的行动大致相反。

机翼失速机翼失速通常会在较低的攻角，从而较高速时，当冰累积。

即使是少量的冰会产生效果，如果冰粗糙，它会造成非常大的影响。

因此，我们建议若是遇到结冰情况，应该在进近的时候适当增大速度。

如何增加在很大程度上取决于机型和冰量。

请参考AFM或POH与冰相关会使飞机机翼失速特性变得不明显，而严重的滚转控制问题，也并不罕见。

积冰可能在两翼之间是不对称的。

隐藏，一边机翼，通常结冰较薄，从而更好地收集的冰，外面的部分可能会首先失速，比另外一边机翼更加迅速。

结冰对滚转控制的影响在副翼的翅膀上结冰可以影响滚转控制。

通用航空（GA）的飞机机翼的设计是使机翼先从跟部开始失速然后向外延伸开来，因此不会干扰副翼控制。

然而，翼尖通常要比后面的地方要薄，所以它们的机翼部分，更容易集冰。

这可能导致翼尖失速，可能会影响副翼，从而对滚转控制造成影响。

如果冰在副翼和边缘的链接部位积累，这可能会影响气流，干扰与副翼的正常运作。

如果副翼功能受损，如果遭遇这样的情况，上轻微向前压盘可能有助于使气流重新附着在副翼上。

Aircraft icingIce in flight is bad news. It destroys the smooth flow of air, increasing drag while decreasing the ability of the airfoil to create lift. The actual weight of ice on an airplane is insignificant when compared to the airflow disruption it causes. As power is added to compensate for the additional drag and the nose is lifted to maintain altitude, the angle of attack is increased, allowing the underside of the wings and fuselage to accumulate additional ice. Ice accumulates on every exposed frontal surface of the airplane—not just on the wings, propeller, and windshield, but also on the antennas, vents, intakes, and cowlings. It builds in flight where no heat or boots can reach it. It can cause antennas to vibrate so severely that they break. In moderate to severe conditions, a light aircraft can become so iced up that continued flight is impossible. The airplane may stall at much higher speeds and lower angles of attack than normal. It can roll or pitch uncontrollably, and recovery might be impossible.Ice can also cause engine stoppage by either icing up the carburetor or, in the case of a fuel-injected engine, blocking the engine’s air source.Kinds of Ice and Their Effects on FlightStructural ice is the stuff that sticks to the outside of the airplane. It is described as rime, clear (sometimes called glaze), or mixed.Rime ice has a rough, milky white appearance, and generally follows the contours of the surface. Much of it can be removed by deice systems or prevented by anti-ice.Clear (or glaze) ice is sometimes clear and smooth, but usually contains some air pockets that result in a lumpy, translucent appearance. The larger the accretion, the less glaze ice conforms to the shape of the wing; the shape is often characterized by the presence of upper and lower “horns.” Clear ice is denser, harder, and more transparent than rime ice, and is generally hard to break.Mixed ice is a combination of rime and clear ice.Ice can distort the flow of air over the wing, diminishing the wing’s maximum lift, reducing the angle of attack for maximum lift, adversely affecting airplane handling qualities, and significantly increasing drag. Wind tunnel and flight tests have shown that frost, snow, and ice accumulations (on the leading edge or upper surface of the wing) no thicker or rougher than a piece of coarse sandpaper can reduce lift by 30 percent and increase drag up to 40 percent. Larger accretions can reduce lift even more and can increase drag by 80 percent or more. Even aircraft equipped for flight into icing conditions are significantly affected by ice accumulation on the unprotected areas. A NASA study (NASA TM83564) showed that close to 30 percent of the total drag associated with an ice encounter remained after all the protected surfaces are cleared. No protected surfaces may include antennas, flap hinges, control horns, fuselage frontal area, windshield wipers, wing struts, fixed landing gear, etc.Some unwary pilots have, unfortunately, been caught by surprise with a heavy coating of ice and no plan of action. Many pilots get a weather briefing and have little or no idea how to determine where icing may occur. However, pilots can learn enough basicmeteorology to understand where ice will probably be waiting after they get their weather briefing. The pilot can then formulate an ice-avoidance flight plan before ever leaving the ground.Ice can form on aircraft surfaces at 0 degrees Celsius (32 degrees Fahrenheit) or colder when liquid water is present. Even the best plans have some variables. Although it is fairly easy to predict where the large areas of icing potential exist, the accurate prediction of specific icing areas and altitudes poses more of a quandary. Mountains, bodies of water, wind, temperature, moisture, and atmospheric pressure all play ever changing roles in weather-making. All clouds are not alike. There are dry clouds and wet clouds. Dry clouds have relatively little moisture and, as a result, the potential for aircraft icing is low. North Dakota, because of its very cold winters, is often home to dry clouds. However, winter in the Appalachians in Pennsylvania and New York often brings a tremendous amount of moisture with the cold air and lots of wet clouds that, when temperatures are freezing or below, are loaded with ice. The Great Lakes are a great moisture source. The origin of a cold air mass is a key to how much super cooled water the clouds will carry. If the prevailing winds carry clouds over water, they will probably be wet. The chart above shows some of the areas of high icing potential. Heavy icing conditions may sometimes occur in the low-risk areas shown on the map above.Fronts and low-pressure areas are the biggest ice producers, but isolated air mass instability with plenty of moisture can generate enough ice in clouds to make light aircraft flight inadvisable.Freezing rain and drizzle are the ultimate enemy that can drastically roughen large surface areas or distort airfoil shapes and make flight extremely dangerous or impossible in a matter of a few minutes. Freezing rain occurs when precipitation from warmer air aloft fallsthrough a temperature inversion into below-freezing air underneath. The larger droplets may impact and freeze behind the area protected by surface deicers.Along a cold front, the cold air plows under the warm air, lifting it more rapidly and resulting in the formation of moist cumulus. Along a warm front, the warmer air tends to slide over the colder air, forming stratus clouds conducive to icing. As you approach the front, the clouds build quickly and the clear air between layers rapidly disappears.Freezing rain and freezing drizzle, including freezing drizzle aloft, are sometimes found in the vicinity of fronts. If you choose to fly through the front, be sure that it does not contain freezing rain or freezing drizzle and other hazardous weather conditions such as embedded thunderstorms. You should plan on flying the shortest route through the front instead of flying the length of the front.Structural IceHow quickly a surface collects ice depends in part on its shape. Thin, modern wings will be more critical with ice on them than thick, older wing sections. The tail surfaces of an airplane will normally ice up much faster than the wing. If the tail stalls due to ice and the airflow disruption it causes, recovery is unlikely at low altitudes. Several air carrier aircraft have been lost due to tail stalls. It also happens to ligh t aircraft but usually isn’t well documented.Since a tail stall is less familiar to many pilots, it is emphasized in this advisor, but a wing stall is the much more common threat, and it is very important to correctly distinguish between the two, since the required actions are roughly oppositeWing StallThe wing will ordinarily stall at a lower angle of attack, and thus a higher airspeed, when contaminated with ice. Even small amounts of ice will have an effect, and if the ice is rough, it can be a large effect. Thus an increase in approach speed is advisable if ice remains on the wings. How much of an increase depends on both the aircraft type and amount of ice. Consult your AFM or POH.Stall characteristics of an aircraft with ice-contaminated wings will be degraded, and serious roll control problems are not unusual. The ice accretion may be asymmetric between the two wings. Also, the outer part of a wing, which is ordinarily thinner and thus a better collector of ice, may stall first rather than last.Effects of Icing on Roll ControlIce on the wings forward of the ailerons can affect roll control. Wings on general aviation (GA) aircraft are designed so that stall starts near the root of the wing and progresses outward, so the stall does not interfere with roll control of the ailerons. However, the tips are usually thinner than the rest of the wing, so they are the part of the wing that most efficiently collects ice. This can lead to a partial stall of the wings at the tips which can affect the ailerons and thus roll control.If ice accumulates in a ridge aft of the deice boots but forward of the ailerons, this can affect the airflow and interfere with proper functioning of the ailerons. If aileron function is impaired due to ice, slight forward pressure on the elevator may help to reattach airflow to the aileron.。