Questions tagged [altitude]

A measurement of vertical distance. Usually measured at either Mean-Sea-Level (MSL) or Above-Ground-Level (AGL).

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Pressure/Altimetry [duplicate]

If someone could help me with this problem and show the steps, I would highly appreciate it. You are on approach to KATL, where the field elevation is approximately 1000ft. During the cruise phase, ...
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Is there a minimum altitude at which FAA drone rules apply? [migrated]

I know the rules for maximum altitude for a drone is 400ft (in general) but is there a minimum height at which the rules are applied? For example is a drone flying 12 inches off the ground subject to ...
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Confused about this Pressure Altitude vs True Altitude Question

The standard question on a knowledge test: "Under which condition will pressure altitude be equal to true altitude?" The answer is: "when atmospheric conditions exist, i.e., 29.92" ...
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How to convert barometric altitude to gps altitude? [duplicate]

In my work I have some challenge with an aircraft altitude values: I was provided with some data from aircraft flight in my country. The data contains variety sensors data (like lat, long, altitude, ...
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1 answer
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How to compute the airspeed change based on the Altitude change

The plot shows that: when I fly with fixed MACH, the true air speed decreases when the altitude increase; when I fly with fixed CAS, the true airspeed increases when altitude increase. So how could I ...
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Why did this flight, that usually flies around 40,000ft only fly at around 29,000ft for the route?

Looking at the flight BY6272 BRS-PMI, it was considerably delayed and flew (according to the flight radar app) at 29,000 feet rather than its usual 40,000 for this same route. It is a Boeing 787 ...
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Is it safe for a huge all black helicopter to be flying BELOW 500 feet over my house, for an hour now, spraying pesticides all over the area

How dangerous is it for a huge all black helicopter to be flying below 500 feet over my house, for a half hour now, spraying pesticides all over the area and my farm animals. It is shaking the whole ...
4 votes
1 answer
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Is the ISA still up to date?

The Standard Atmosphere dates back to 1962 when Earth was colder. The 1976 update didn't make changes within 50 km altitude (the tropo- and stratosphere). It assumes 15°C at sea level, decreases until ...
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Does a plane's service ceiling vary with season/temperature?

Aircraft use barometric altitude, e.g. FL300 is the barometric altitude of 30,000 ft MSL. In winter however, FL300 is actually lower than the absolute altitude of 30,000 ft because of a cold and ...
2 votes
1 answer
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What was the reason for my flight’s low cruise altitude?

I’m a fairly new aviation enthusiast and am just curious to know the answer to this question. I flew Boston to Newark yesterday 14/6/22 (UA2396) and we cruised at or under 16000 feet for the whole ...
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Why does ADS-B altitude from multiple landed planes vary so much from one plane to another?

When viewing ADS-B data from sites like FlightAware and Flightradar24 (and also from a personal antenna), the landed altitudes vary greatly from one aircraft to another. What accounts for this ...
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Is it appropriate to determine approximate flight altitudes based on ADS-B landed altitude compared to runway elevation?

For small aircraft flying below 2,500 ft. AGL, is it appropriate to compare the landed ADS-B altitude (pressure calibrated AMSL) to the elevation of the runway in order to compute a reference offset ...
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Minimum Safe Altitude vs Emergency Safe Altitude

Is there a difference between Minimum Safe Altitude and Emergency Safe Altitude? Or are they same things used by different authorities (MSA by EASA and ESA by FAA)?
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What is the operating altitude of jetliners?

I am performing a science project, and this involves knowing the average operating altitude at which commercial passenger airplanes (jetliners) fly. I am trying to find minimum operating altitudes and ...
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3 answers
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Do pitot tubes account for reduced pressure at altitude?

Do pitot tubes account for reduced pressure at altitude? Does indicated airspeed reduce with altitude? If so, how much? Is it different for small planes vs big commercial airliners?
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What is the AeroVironment Helios' Kármán line?

If it's true that the NASA/AeroVironment Helios maintained level flight 96,000 ft above sea level at a maximum airspeed of 23.5 kts (43.5 km/h) I assume it must have a very high Kármán altitude, the ...
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Is the U2's 74,000 ft the highest a turbofan plane ever has gone?

What is the altitude record for a turbofan? The (usually) turbofan-powered U2 has gone to 74,000 ft (22.6 km) MSL, but did any turbofan plane surpass that, in a zoom climb for instance and with ...
8 votes
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At what altitude can the sonic boom no longer be heard at sea level?

As others have stated here, you can hear the sonic boom of planes flying by at a fairly high altitude, ~80 000 ft. At what altitude would the sonic boom no longer be noticable at sea level? To add to ...
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Would an airliner climb higher late in the flight because of the consumed fuel (lighter airplane) to save more fuel?

Some people said airplanes would fly higher in the late period of each flight, because the fuel is consumed, and the airplane is lighter. Higher altitude and less dense air is enough to support the ...
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Air density decreases as temperature increases - but air also gets cooler as it expands; does this create a feedback loop? [closed]

First, I apologize for the sloppy title. I had a tough time phrasing this as a concise question. For a column of air at a given pressure, density decreases (the air expands) as temperature increases. ...
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Do private jets ever fly at FL510? If so, at what occasion?

Most private jets have a service ceiling of 51,000 ft. A service ceiling is the altitude at which a plane can climb no more than 500 ft/min, right? However, on flightradar24 I don't remember having ...
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Is a balloon's record altitude measured from the top of canopy, the bottom of the basket, or some other point?

I wonder where exactly on the balloon is its altitude measured. By the time a space balloon reaches its maximum altitude it is extremely large, the higher the larger. The record altitude for a balloon ...
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Is there a place where altitude while flying is negative?

while testing and working with avionics systems I have never seen an altitude near 0 or negative. Is there a place when flying above the Altitude tape shows -ve value ? Maybe while flying between ...
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Are ERA5 Pressure Level and ADS-B Geometric Height comparable?

I have two wind data sets that I want to compare: a) Aircraft derived data (ADS-B and Mode-S). b) ERA5 Reanalysis data. To compare both I need altitudes to be comparable. On data set a) I have the ...
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How can I compute indicated altitude?

I would like to compute what an altimeter would display given a true altitude and atmospheric conditions. Specifically: Given: True altitude, in feet Outside air temperature, in degrees C Local ...
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Correcting uncorrected pressure altitude on recorded data

I have some recorded commercial flight data that contains altitude readings defined as "uncorrected pressure altitude." So I have a sequence of lat/lon/alt/timestamps as the aircraft travels ...
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How to most likely get a flight that will go above 40,000 ft?

I wonder if there are passenger flights that would reach cruise altitudes higher than 40,000 ft (i.e. reach 41,000 ft for instance) more likely than others. It also depends on the plane of course, but ...
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What is the minimum altitude needed to return to the takeoff airport in a 737 after dual engine failure?

Last week, I had my first lesson in a 737 sim. The instructor, when talking about risks with flying the 737, said the only time it would be "game over", would be if you had a double engine ...
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How to calculate density of ISA+10ºC at 11705m? [closed]

I know how to calculate the density under normal ISA conditions at a given altitude, but I'm unsure about how to go about calculating it at ISA+10ºC, or at any ISA+XºC conditions.
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How is a design cruise altitude picked? [duplicate]

Different planes have different design cruise altitudes, given by the manufacturer. You can find these in their Airport Planning Manuals or in Jane's All the World's Aircraft. I know that the first ...
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Do aircraft travel faster at higher altitudes?

I'm aware of the difference between TAS and IAS, and how IAS gets lower in reference to TAS as you climb and the air gets thinner. What I'm trying to figure out is whether or not an aircraft's IAS ...
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If absolutely nothing changes except temperature, does indicated altitude increase, decrease, or stay the same?

I have gotten conflicting answers from CFI's on this one. In bold are the only things that changed or would potentially change. Initially: Aircraft is parked at a very dry (to factor out humidity) ...
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1 answer
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Can a hybrid electric turboprop reduce fuel consumption 30% on regional flights?

UTC has a hybrid electric research project called Project 804, in which it claims that augmenting takeoff turbine power with electric power allows a smaller turbine for cruise, thus saving 30% of fuel ...
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What happens when I set my altimeter at the starting of my flight?

When I set my altimeter to 29.92 mm Hg, I have my pressure altitude. However, what am I doing, when I set my altimeter before each flight. My instructor tells me to hear for AWOS, and set the ...
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1 answer
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What was the most efficient cruising altitude of the Lancaster bomber?

An earlier question concerning lower high altitude cruising fuel efficiency of the B-29 bombers with 4 x Wright R-3350 air-cooled radial Cyclone engines made me wonder about the Lancaster bomber, ...
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1 answer
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Is the true altitude always lower than the indicated altitude as long as a correct local altimeter (QNH) is set on the altimeter?

Given the fact that the altimeter setting is corrected for the temperature of the airport, on the condition that a correct local altimeter setting (QNH) has been made to the altimeter, is the true ...
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What is the altitude record for the F/A-18 Hornet?

Does anyone know how high (above MSL) the F/A-18 ever went? Its service ceiling is 50,000 ft, but when going up steeply, is it able to surpass 100,000 ft altitude?
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Is there a regulation that defines when to use QFE or QNH for landing?

Is there an EASA regulation that says to use QFE or QNH when landing?
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What is baro corrected altitude?

I have data from an aircraft which I am trying to understand. One column contains the baro corrected altitude (in ft, e.g. 256) and another the pressure altitude(also in ft, e.g. -44). The two example ...
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4 answers
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Why doesn't temperature affect Pressure Altitude?

In this picture: it states the tops and bottoms of the 3 columns of air have the same pressure. This explains the error in altitude indications given in a non-standard temperature. Pressure only ...
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1 answer
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How to obtain true altitude from indicated altitude, temperature and QNH?

maybe it's a little impolite to ask but I got stuck with knowing bunch of formulas and not understanding how to use it: Can you help me on understanding how the correct answer 7300ft came out of the ...
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What airspeed is required at sea level to create the same aerodynamic pressure as cruise altitude?

I would like to know what speed would be required, at sea level, to exert the same aerodynamic pressure as experienced at cruise altitude. For example, if an airliner were traveling at 500kn at 35,000'...
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Is air to air refuelling possible at "cruising altitude"?

When an aircraft uses air to air refuelling are there constraints on the maximum altitude this can take place at? For instance I'm guessing that a Boeing Globemaster when on a long journey would ...
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Why is Transition Altitude fixed but Transition Level is not?

In Jeppesen approach plates we see that the Transition Altitude of the aerodrome is fixed but the Transition Level is not fixed and is given by ATC. What is the reason for this?
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Can Transition Altitude (TA) and Transition Level (TL) be equal?

In Europe, is it possible that Transition Altitude and Transition Level are equal, that is, TA=8000 ft and TL=FL080? In that scenario, at 8000 feet, what pressure (QNH or QNE) should be set in the ...
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How can I work out Sea Level Pressure from QNH?

I am a little confused, is the QNH the current pressure at Sea Level? Therefore putting it into the altimeter will give your current altitude on the ground in pressure altitude relative to current sea ...
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Is it likely that an aircraft could have been near 10° 08' north at local midnight August 26/27, 2003?

Edit: The astronomical data turned out to be different. I'm keeping the constraints below as they where, but those are not relevant to finding the closest person to Mars. This is part of an effort to ...
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2 answers
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How does altitude affect the TAS and thrust of an electric fan powered aircraft?

I'm confused about the relation between IAS, TAS, thrust, and shaft power, for an electric application. Yes, higher air is thinner, and thrust goes down due to higher airspeed. What I've researched ...
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How high can a ramjet go?

Yesterday, there was an off-topic question on Space.SE, asking if a ramjet-missile could place itself in orbit. Impossible for a ramjet, obviously, as it requires a high speed flow of air and is too ...
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What is the definition of "geometric height" referred in the ISA Model?

The International Standart Atmosphere document always mentions the "geometric height" (along with the geopotential hieght) in their calculations. I predict that it means orthometric height, ...

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