I am a huge fan of flight simulation games (and aircraft mechanics in general), and this is a question that has always been interesting to me. Why are some crafts able to fly in super cold areas without freezing over and inevitably plummeting, while others have basically no chance of staying airborne?
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They’re designed for it.
They need to use different fluids, or have their systems designed differently. That’s more expensive and less cost-efficient. They may be more complicated and harder to maintain. There’s less demand for planes to fly in those areas, because it’s also less hospitable for humans.
So it makes more sense for normal planes to be cheaper and use simpler systems that work in more average climates, but also have customized planes for the specific jobs that require flying in harsh climates.
Airplanes only freeze under certain circumstances, put succinctly, it is actually too cold for ice to form on the plane. Plus, modern jets use a technology called ‘bleed air’ to warm the critical surfaces of the plane so they don’t freeze. Other planes use rubber boots that expand and contract to break the ice off the fligt surfaces.
The bigger problem is fuel temperature, we know exactly when Jet fuel turns to gelatin so provided you can keep your fuel warm enough you can fly in extreme cold climates.
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Lack of moisture. Ice requires both cold temperatures and moisture. Even in the lower latitudes, it’s very cold at 30000 feet. Unless the plane is flying through a storm, icing isn’t really a problem. However, planes also typically have heated wings and other surfaces to reduce icing.
There is no reason why they should not. In fact airplanes fly in cold air all the time as they fly high enough in the sky for the air to be far bellow freezing. The problem is related to humidity. It can be cold all day but unless there is actually something that can freeze to ice there is no problem. At altitude and also on the poles it is generally quite dry. So there is no ice forming even though it is cold.
There are however things that aircraft can do to better operate in these temperatures. In the engines the exhaust is hot and can be used to heat up areas that can clog up with ice. There are also electrical heaters. For piston engines they can heat up the carburetor and bypass the air filter. Jet engines are more complex but might have similar settings. You have things like heating the piton tube and such.
Another issue is that the wings collect ice changing their shape and making them stall. This may cause the airplane to fall out of the sky. So you might sometimes see the leading edge of the wing be made of a rubber tube. The tube can be pressurized to change its shape and then the pressure is released changing its shape again. This cause any ice that forms on these leading edges to fall off. The ice on the rear of the wings will then be exposed to the full force of the incoming air and be blown off. Some aircraft even have this on the propeller. These are not common on commercial airliners but when flying on the poles they often follow more rugged smaller cargo airplanes with these modifications installed who can report on the conditions.
I used to build airplanes! It’s my time to shine lol
Planes that need to fly at high altitudes or in very cold conditions have specific systems designed to mitigate the effects of the cold weather. First, let’s separate aircraft into two categories:
**Aircraft with non-pressurized cabins.** This type of airplane is designed to fly at relatively low altitudes (under 10,000 feet, generally). At this flight level, temperatures are colder than what you’d see at ground level, but it’s often above freezing.
**Aircraft with pressurized cabins.** This type of aircraft has a cabin (where you sit) that can be pressurized. This is necessary when you fly above somewhere around 10,000 feet, because the air gets too thin to provide the oxygen required by humans. At flight levels above 10,000 feet, temperatures start to drop rapidly.
Both types of aircraft can be prepped to fly in cold conditions, but pressurized aircraft more or less have to be, or they’d be very limited in where & when they can fly.
Examples of cold weather features:
Carburetor heater. As the engine sucks air in, ice can form around the inlet of the carburetor. Carb heat prevents this.
Pitot tube heat. Pitot tubes measure fluid velocity, and air is a fluid. There are a couple different types, and aircraft will often have more than one. If these tubes freeze up, you’ve got a problem, so they heat them.
Wing de-icing. Ice can form on the leading edges of the wings, so wing de-icers rely on a combination of heat and mechanical systems to remove ice. The ones I’ve worked on can heat up, but they also have inflatable rubber bladders that can blow up to shed ice, then shrink back to normal wing shape.
Keep in mind that everything I’m talking about here is on light aircraft. Large, commercial aircraft have much more sophisticated systems.
Getting the plane to start and take off in extreme cold is the trick. Planes have a minimum temperature requirement below which they will likely not start. When operating at or near that temperature the pilot may choose not to turn off the engines to ensure they are able to take off.
Source: Flown on small planes in the Canadian Arctic for work.
The temperature drops about 2C per 1000 feet (yes I just mixed metric and imperial – it’s an aviation thing)
So flying in freezing conditions happens a lot. For ice to form on a plane specific conditions have to exist that give the right amount of moisture and temperature. It’s kind of like a middle zone between too hot and too cold, then combine that with moisture and you have icing conditions. This is for most surfaces on the plane. This is the part that I think answers what you’re getting at. The mechanics of how it’s avoided are explained well in other comments.
For things like the pitot and carb icing is possible even in very hot temperatures and actually very likely. Even up to like 30C. I don’t think your question was aimed at this though. Most planes are outfitted with measures to avoid this because it is a very serious scenario to find yourself in
The South Pole (average summer temperature -40) has two main aircraft types present, DC-3s and LC-130s. They’re both really old. The jet fuel they use is called AN8, which is modified to flow at very low temperatures. The LC-130 pilots leave the engines running when they land at the Pole, since it’s a lot easier than trying to start the plane cold. The DC-3s have special heaters to make them able to start somewhat easily in that weather.
I’m going to toss in my 2 cents just to make sure rotorcraft are represented.
On a larger military helicopter like the H-60 or H-53, there are multiple anti-ice/de-ice features.
First some terms:
Anti-ice: Prevent ice from forming in the first place
De-ice: Remove ice that has already formed.
Most ice systems are anti-ice in nature. Some of these may also serve to de-ice if needed, but are best used before ice has formed.
Here are the types of ice systems on a helicopter:
Engine Anti-Ice: This system injects hot engine bleed air into the engine inlet to keep ice from building up on the compressor.
Pitot-tube Heater: Keeps the pitot-tube from building up ice, which can result in invalid airspeed measurement
Rotor blade de-ice: This is a system of heating elements installed on the leading edges of main and tail rotor blades, similar to the heating elements on the leading edge of airplane wings. It can prevent ice from forming and can remove some ice if it has already built up.
So far, this isn’t too different from a fixed wing aircraft. There are a few interesting items just for helicopters:
1) Rotor blade de-ice has to be used very carefully. The heating pads take up a much larger percentage of the space on a rotor blade than they do on a wing of an airplane. They are typically only turned on for a little bit at a time. There is typically an electronic component that cycles them on and off. Run them too much and they can burn holes in the blades. On an H-60, all four main rotor blades combined weigh only 400 pounds, for an aircraft that has a takeoff weight of 22,000 pounds. There isn’t much surface area to start burning holes in blades.
2) Ice buildup on the wing of an airplane can impact lift and add weight. Ice buildup on a rotor blade is similar. However, there is an extra danger for rotor blades. As ice forms, or even as it falls off, it can throw off the balance of the rotor system. This can cause significant vibrations and even lead to damage. Enough imbalance can lead to dynamic instability of the rotor system, which is just a fancy way of saying that the rotor violently destroys itself. There is even a scary sounding term for how blade de-ice systems can cause instability in the rotor system: “Asymmetrical Ice Shedding”.
There are limits to these systems. Many helicopters are not rated to fly in icing conditions at all, and for those with the necessary ice systems, they are often rated only to fly in areas that might experience light to medium icing.
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