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51 votes
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Can commercial airliners fly over central Antarctica during winter?

Surface air temperatures aren't really going to be relevant for an airliner. The temperature of the troposphere doesn't vary that much. In fact, the troposphere is warmer at the poles (from Wikipedia ...
Greg Hewgill's user avatar
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43 votes
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Why was the SR-71 made of titanium?

Because the specific strength of titanium at higher temperatures is better than that of steel (both are much better than that of aluminium). Specific strength vs. temperature is shown on the above ...
Koyovis's user avatar
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33 votes

Can commercial airliners fly over central Antarctica during winter?

They could, if only they were allowed to. From § 121.161 Airplane limitations: Type of route. (a) Except as provided in paragraph (e) of this section, unless approved by the Administrator ...
Koyovis's user avatar
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32 votes
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Would building a large asphalt square or painted dark black area create a "thermal generator" for glider use?

Yes, if it was large enough you could expect decent thermals from it, but not all the time. I've flown over mall parking lots where there is maybe 20 acres of asphalt, expecting a boomer, but no joy. ...
John K's user avatar
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23 votes
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If you depressurize an aircraft at FL340, will the temperature inside fall to match the temperature outside?

This depends entirely on how you depressurized it. Depressurizing the aircraft by fully opening the outflow valve will lower the temperature somewhat, but will not bring it to that outside. The ...
Therac's user avatar
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22 votes

Does Nitrogen inside commercial airliner wheels prevent blowouts on touchdown?

Apart from the paragraph you quoted, here are a few more reasons. Dry nitrogen is specified for aircraft use. I believe the rules say that any gas used cannot exceed 5% oxygen content. Because its ...
Anilv's user avatar
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21 votes

Why was the SR-71 made of titanium?

There is a great article here that breaks it down in depth but its combination of factors made it the best choice, not a single factor (i.e. heat resistance). But, in reality, the strongest titanium ...
Dave's user avatar
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17 votes

How hot do internal parts of jet engine get?

This parameter is called Turbine Inlet Temperature (TIT) Turbine Inlet Temperature (TIT) is the temperature of the combustion chamber exhaust gases as they enter the turbine unit. The gas ...
user3528438's user avatar
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15 votes

What sort of issues related to extreme heat (115°F, 46°C plus) would prevent takeoffs or landings?

Aircraft performance is a many-faceted topic. Insofar as it being so hot that operation is prohibited, a couple of things come to mind. Aircraft performance figures are supplied by the aircraft ...
Terry's user avatar
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14 votes
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Flex temperature isn't actually "fooling" the FADEC, right?

There are at least two misconceptions in your question: The way I understand flex temperature is: It's a user interface for pilots to request a derating of engine power to reduce wear on the engine. ...
Bianfable's user avatar
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12 votes

Does Nitrogen inside commercial airliner wheels prevent blowouts on touchdown?

There is some truth in the claim about inerting. Mostly, blowouts are as a result of high temperatures weakening the rim and tyre and increasing gas pressure within it, rather than being the result ...
David Richerby's user avatar
12 votes

Would building a large asphalt square or painted dark black area create a "thermal generator" for glider use?

I made a short LES simulation The color is thhe potential temperature and the scale span is 1.8 K between blue and red. There is a hot patch 100 m x 100 m in the middle. There is 0.1 K.m/s (~110 W/m^...
Vladimir F Героям слава's user avatar
11 votes
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Do jet engine exhausts usually glow orange?

Both images you posted are of Pratt&Whitney J58 afterburning turbojet that was used on the Lockheed A-12 and Lockheed SR-71 aircraft. That engine ran particularly hot. The engine was designed for ...
Jan Hudec's user avatar
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11 votes

Does Nitrogen inside commercial airliner wheels prevent blowouts on touchdown?

In addition to what the current answers mention, it should be noted that the danger is not merely theoretical, though blowouts on touchdown aren't necessarily the primary concern. Mexicana flight 940 ...
reirab's user avatar
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10 votes
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What is the temperature of the air leaving the combustion chamber of a CFM56-5C?

Quick answer: At the design point considered, which is assumed to be takeoff conditions, a CFM56-5C combustor raises gas temperature to 1360°C (the share of the compressor in this raise is about 600 °...
mins's user avatar
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9 votes
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What temperature is the vapor that forms around a maneuvering aircraft?

I think I've linked to this resource in one of your previous questions. NASA SP 514 On page 5 (pdf page 15), he derives an expression for the relative humidity around an aircraft. $$ RH_l=RH_\infty\, \...
Rob McDonald's user avatar
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8 votes
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Why Apollo 11 was launched in summer? (Performance question)

The temperature of the environment doesn't have a significant impact on the performance of a rocket engine. Air breathing engines have better performance in cold air because the mass density is higher ...
Alec Martin's user avatar
8 votes

How does latitude affect the air temperature at 8 km altitude where planes fly?

In the troposphere, air at altitude is colder than air at ground level. But surprisingly, air at altitude at the poles can be warmer than air at altitude at the equator. From the wiki article on ...
Koyovis's user avatar
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8 votes

The phase having the hightest TIT for a flight mission

The highest ITT/TIT/EGT is always seen as brief transient during start, during initial takeoff thrust setting, or during slam accelerations (go-arounds). On the General Electric CF-34-3B1 (the engine ...
John K's user avatar
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7 votes

If you depressurize an aircraft at FL340, will the temperature inside fall to match the temperature outside?

Assuming the cabin is pressurized to a pressure equivalent of that at 8000ft, the initial pressure is on board is $P_1$ = 75262.4 Pa, and the temperature is T1 = 20ºC = 293.15K At FL340, the outside ...
DeltaLima's user avatar
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7 votes

What can cause the engine temperature to be high in piston engines?

Low oil quantity, improper cooling, running excessively lean of peak. Excessive boost from a turbo or supercharger at high altitudes where sufficient cooling is not possible. Ther are quite a few ...
Romeo_4808N's user avatar
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7 votes
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How much aerodynamic heating do jetliners endure?

Based on the formula already shown in this answer, we can calculate the TAT (total air temperature), which is the temperature reached at the stagnation point1, from the SAT (static air temperature) ...
Bianfable's user avatar
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7 votes

Would building a large asphalt square or painted dark black area create a "thermal generator" for glider use?

Yes. Sunlight is about 1000 W/m2. Absorbing it is a good way to get some heat. We can improve on your design a bit. A good portion of sunlight is visible to the eye, but some of it is not. Not all ...
Anonymous Physicist's user avatar
7 votes
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Why are the brake temperatures so high during the cruise?

The brakes will be above ambient temperature of the departure airport due to the braking action during taxing. While airborn there is little airflow to cool down the brakes, so this temperature will ...
tsg's user avatar
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7 votes

Why was the SR-71 made of titanium?

NASA was the final operator of the Blackbird and this NASA report contains several valuable information about the SR-71. Just download and read it, it has no equation in it and it's written in a ...
sophit's user avatar
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6 votes
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What is the operating temperature of a turbofan engine, and how is it kept at that temperature?

Q1: Assuming that by operating temperature you mean turbine inlet temperature, this article says the Pratt & Whitney F135 engine in the F-35 (JSF) has a TIT of 3600 °F (1982 °C / 2255 K), but that ...
Penguin's user avatar
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6 votes

What is the operating temperature of a turbofan engine, and how is it kept at that temperature?

Yes, if you could increase the combustion temperature in the hot section of a gas turbine, you could dramatically increase the efficiency of the engine. The problem of course is finding materials ...
Romeo_4808N's user avatar
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