Questions tagged [temperature]

The intensity of heat found in an object or living thing.

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5
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2answers
925 views

Flex temperature isn't actually “fooling” the FADEC, right?

I'll be using Airbus terminology here because that's what I know, but I guess the concepts are universally applicable. The way I understand flex temperature is: It's a user interface for pilots to ...
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1answer
125 views

What is the speed above which painting an aircraft black (or dark) results in lower skin temperature?

The Concorde is painted white for thermal reasons. If I understand correctly, it is done to reflect as much radiation as possible in order to lower tempereture. But when the skin is really hot (SR-71, ...
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1answer
107 views

How hot is supersonic intake air?

How hot is the air at the compressor inlet at supersonic speed? For instance the Concorde at mach 2.2 or other jet engines at even higher speeds.
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0answers
26 views

What happens to the dynamic temperature in the boundary layer at supersonic speed?

In the boundary layer for a supersonic flow, does the dynamic temp decrease? Thank you
6
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1answer
123 views

Why does the temperature rise in the boundary layer after a shock wave?

Is it because the BL thickens after the shock so the drag increases, causing a increased friction? Here M=0.82 far from the airfoil, the picture represents the static temperature in Kelvins around the ...
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0answers
16 views

Effect of Exhaust Mixer on the temperature of Core Exhaust

After the core exhaust leaves the turbine section (having a temperature of about 900 C ), and it mixes with the by-pass air via the exhaust mixer , what will be the resulting temperature of the ...
10
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3answers
4k views

How hot do internal parts of jet engine get?

How hot does a jet engine get? I'm interested in the temperature of the parts, not of the exhaust or combustion. If you took temperature of an engine after a flight across the Pacific Ocean what are ...
4
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1answer
234 views

How do airports in hot climates handle extremely high temperatures?

In June 2017 dozens of flights were cancelled in Phoenix, Arizona because of temperatures exceeding 120 degrees Fahrenheit/48.9 degrees Celsius.1,2 Hot air at a given air pressure is less dense, ...
6
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3answers
2k views

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

Assuming you’d have an oxygen mask on before hand, and you depressurized the aircraft at FL340, would the inside and outside temperatures quickly become the same?
9
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3answers
2k views

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

Is the air temperature (at 8km) above the North or South poles colder than the same altitude above the equator? Why? Ground level air temperature difference between coldest and warmest places on ...
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2answers
96 views

Why and how do atmospheric properties sometimes vary from the ISA? [closed]

I'm curious as to why sometimes atmospheric properties don't match the ISA's. One reason I am considering is due to calibration discrepancies. By atmospheric properties I mean temperature, Density, ...
2
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1answer
146 views

What are the equation linking static air temperature with true airspeed & altitude?

If I want to calculate static air temperature (OAT), but I'm only given an altitude and a true airspeed. Is there such an equation that relates these principles together. I've had a look at wikipedia ...
2
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1answer
180 views

How can I calculate turbofan efficiency as a function of turbine inlet temperature?

I know that increasing the turbine inlet temperature (TIT) increases the overall efficiency of the jet engine. So I wanted to find the overall efficiency as a function of TIT. I used the equations ...
0
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1answer
83 views

How to compute the change in static temperature using only altitude?

I'm given an initial altitude of FL290 in ISA conditions, and the aircaft is said to climb to reach FL310. How can I use this to calculate the change in static temperature between the two flight ...
2
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1answer
169 views

Why Apollo 11 was launched in summer? (Performance question) [closed]

The question could seems stupid, but i think that best moment to launch a rocket is when temperature is lowest in order to achieve the best performance in a reaction engine. I do not know if there is ...
3
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2answers
231 views

Can an S-duct fit a turbofan exhaust instead of the intake?

Can an S-duct fit a turbofan exhaust instead of the intake? The idea here is to merge 2 exhausts into one at the exact center of the tail. This would be for twin-engine aircraft that have both engines ...
16
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2answers
4k views

What is the reason for setting flaps 1 on the ground at high temperatures?

Yesterday I've seen an A320 standing at the gate with flaps 1. While this question answers, why the flaps should be up, is there any reason to retract the flaps to 1 instead of up? In addition it ...
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3answers
3k views

Does Nitrogen inside commercial airliner wheels prevent blowouts on touchdown?

I just watched the first episode of Inside Mighty Machine where civil engineer-turned-host, Chad Zdenek, discussed innovations of the 747. One innovation he discussed was the increased number of ...
4
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1answer
545 views

Who controls the cabin air temperature?

I understand the B737-800 has two air conditioning packs that handle the temperature of three zones: the cockpit, the fwd cabin and the aft cabin. I understand that which pack is turned on is ...
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1answer
936 views

What's the formula to calculate static air temperature?

What's the formula to calculate external temperature (static temperature) of an aircraft, given that I have Mach, TAS and altitude? Since I don't know the formula, I tried to search on Google. But I ...
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1answer
268 views

What is Temperture of VSI and limits of accurate value?

Within a temperature range of +50C and -20C the VSI is Accurate to within limits of : A)+- 200 ft/min B)+- 0 ft/min c)+- 75 ft/min D)+- 300 ft/min
3
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1answer
340 views

Is there an ideal air temperature for best performance in a light aircraft?

I know cold air is better for engine performance in general, colder air is also denser making lift components stronger(from what I understand). I was just wondering if there is a temperature or a ...
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1answer
1k views

Why is the relation of height and temperature different when calculating altitude?

I'm trying to grasp the essence of altitude calculations. One thing I can't figure out in my head is this: In the International Standard Atmosphere (ISA) the temperature of the air decreases with the ...
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3answers
373 views

Why is extreme cold weather a challenge at airports, since jets operate at extreme cold conditions in flight?

Wondering what specifically the issues are. Obviously, taking off and landing have more 'moving parts' but more curious about the actual extreme cold. I assume the operating temperatures at cruise ...
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1answer
416 views

What is the standard temperature used in this true altitude equation?

The control tower of a certain airport with true altitude of 2000ft informs the pilot that QNH is 900hPa and the temperature at the airport is -10 degrees Celsius. The airplane is at FL300 (vertically ...
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1answer
1k views

Why do brushless motors heat up? [closed]

I would like to know what makes a brushless motor heat up. I'm aware of the problems generating the high temperature such as wire contact problems or overloaded motors. I want to know what makes a ...
2
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0answers
80 views

What is the operating temperarature of a scram jet at its theoretical maximum speed?

What is the operating temperature of a scram jet at its theoretical maximum speed of Mach 24? For those with access to a simulator and do such simulators exist and are they possible? Given this ...
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1answer
199 views

Where is the mistake in this air density calculation?

I intend to compute the air density, $\rho$ at an altitude of $h=15000ft=4572m$, with an ISA deviation of $\Delta_{ISA}=18^{\circ} F=10\,K$. Well I first computed the real temperature of the air at $...
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1answer
523 views

When temperature increases what happens to the air molecules and aircraft while landing and takeoff during hot weather? [closed]

Just out of curiosity on a hot weather with temperature increases what happens to the air molecules and aircraft during landing and takeoff?
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2answers
5k views

How to calculate outside air temperature at a certain altitude?

I am a PPL student and working on the cross-country planning. Let's say the OAT is -13º @ 6000', how to calculate the OAT @ 7000'?
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0answers
78 views

Temperature of airplane while flying? [duplicate]

When the air-plane reaches to the altitude of about 12,000 m or so, the airplane's outside cover is very cold due to the air temperature or very hot due to the friction? Or it depends on different ...
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2answers
337 views

Can heat from the engine inlet be used to produce thrust?

As the engine inlet temperature increases, Is more heat energy provided by air? if yes then can we utilize that heat energy to produce more thrust?
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1answer
883 views

Does an increase in inlet temperature affect fuel flow and power output?

The fuel flow rate decreases as the inlet temperature of the air entering the engine increases. Will the engine produce same amount of power as when the fuel flow was higher?
40
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2answers
12k views

Can commercial airliners fly over central Antarctica during winter?

For example, if an airline decided they wanted to run year round flights on the great circle from Perth to Buenos Aires with a commercial airliner (e.g. A380 or B747), would they be able to do so? Or ...
2
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1answer
322 views

Are there typical values of pitot-static and TAT probe measurement uncertainties?

I'm working on flight sensors for a project and I'm supposed to model noise in the Static Port, Pitot tube, and TAT probe measurements. I looked a lot for it online and could not get a convincing ...
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1answer
1k views

Am I correctly calculating the density altitude?

I came across the following question while studying for the FAA PPL written test: Determine the density altitude for these conditions: Altimeter setting: 30.35 Runway temperature: +25°F Airport ...
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1answer
211 views

Why do different aircraft have different maximum operating temperatures?

I was reading this Wired article about the recent Phoenix heat grounding some jets. It's a great read on why heat is detrimental to lift, but it raises a point it never answers (emphasis mine) ...
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4answers
11k views

Is there a maximum or minimum temperature for take-off and landing?

Is there a maximum or minimum temperature that a plane can take off or land at?
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0answers
100 views

What is the temperature at the center of a gas turbine disc?

I realize that it varies with the temperature at the inlet of the turbine, materials, dimensions, etc. But I would be interested in knowing an orientative value. For example, for a turbine which has ...
5
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1answer
2k views

What is the temperature of the air leaving the combustion chamber of a CFM56-5C?

What is the temperature of the air leaving the combustion chamber of a CFM56-5C? I was wondering as I could only find out that the fuel burns at around 1500 Celsius but this can't be the same as the ...
5
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1answer
4k views

What is the relationship between temperature, dew point and the formation of clouds?

What can you infer from the temperature / dew point values in this METAR? EGJG 121630Z 09012KT 9999 SCT006 15/14 Q1015 I understand the temperature is 15 degrees and the dew point is 14, and I ...
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1answer
3k views

Why can't Norwegian's Boeing 787 operate from Vegas during hot weather?

In a German news article it was stated that the additional weight (Norwegian puts 291 passengers on their 787-8) leads to operations restrictions in Las Vegas when temperature conditions exceed 40°C. ...
4
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2answers
280 views

Can the ECS work in an unpressurized cabin?

Can you control the cabin temperature if the cabin is unpressurized? What if the "cabin" isn't really that big, like a fighter aircraft? For example, could I cruise in comfort at 20,000 ft in an ...
3
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1answer
528 views

Is airframe heating a concern at subsonic speeds?

It is a well-established fact that airframe and skin heating due to air friction is a significant concern with supersonic aircraft. However, below Mach 1 (i.e. typical commercial aircraft flights ...
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2answers
6k views

How can OAT and SAT differ?

From YouTube. I always thought SAT (Static Air Temperature) and OAT (Outside Air Temperature) were the same thing. So does this answer, so does Wikipedia: [The] outside air temperature (OAT) or ...
6
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1answer
2k views

What is the fuel temperature in the tanks during a flight?

I'm trying to estimate the temperature of fuel stored in wing tanks during the flight. In my situation, I'm considering two wing tanks of 2000 liters each, one on each wing, at 20°C before the flight ...
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2answers
612 views

Is it legal to fly GA aircraft in temperatures above what is shown on the performance charts?

Most Cessna aircraft have performance charts the range from 0 to 40 Celsius. I've had a CFI tell me that the FARs prohibit flight if the OAT exceeds 40C or whatever is shown on the performance charts. ...
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2answers
708 views

How do pilots calculate the temperature to put Into the FMS for an FLX takeoff?

I recently read an article about derated takeoffs and I understand the concept, but how do pilots know what temperature to put into their FMS if they want an FLX takeoff? Some people say it's a rough ...
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7answers
5k views

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

I recently flew into and out of McCarran Airport Las Vegas (LAS) and a local told me that they never report the air temperature at the airport above 115°F (46°C) because the FAA does not allow ...
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1answer
4k views

Why are min and max temperatures (TN TX) not published in TAFs in the United States?

I know that other countries like Brazil, Argentina, etc. do publish minimum and maximum temperatures in their Terminal Aerodrome Forecasts, abbreviated TN and TX. But why are they not shown in TAFs in ...