A message from our CEO about the future of Stack Overflow and Stack Exchange. Read now.

Questions tagged [altitude]

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

Filter by
Sorted by
Tagged with
2
votes
1answer
151 views

What is the altitude required to bypass Russia's airspace restrictions for airlines? [duplicate]

Given that Russia charges a lot for flights over Siberia from Europe to Asia, would flying above the Kármán line (100km) effectively bypass this restriction (from legal perspective) ? If not, what ...
0
votes
2answers
61 views

Is there a standard international Minimum Obstacle Clearance Altitude (MOCA)?

In Turkey, the Minimum Obstacle Clearance (MOC) in primary areas is 300m; what about other countries and region?
2
votes
2answers
161 views

What does the altimeter indicate if it's at a certain elevation

The purpose of the altimeter is to show the pilot the altitude and the pressure above a fixed level. It uses barometric pressure and is 29.92Hg in ISA conditions. What I dont understand is, how can ...
0
votes
0answers
30 views

How long does it take to die when we would in altitude that push us to hypoxia? [duplicate]

How long does it take to die when at an altitude sufficient to induce hypoxia ?
1
vote
2answers
96 views

How does cabin pressure vary with respect to ambient pressure during descent?

I came across this statement in a book - "During a descent, the cabin pressure in a pressurized aircraft usually climbs at as lesser rate than ambient pressure". Could someone explain this statement ...
2
votes
1answer
130 views

What is transition altitude?

Now I know the definition of transition altitude - it's the altitude where pilots change their barometric altimeter datum from regional pressure setting to 1013.2hPa. In USA the TA is 18,000ft. But I ...
0
votes
1answer
130 views

Is there a difference between altitude and flight level? [duplicate]

I came across a question in Quora asking the difference between altitude and flight level. One of the answers said that anything above the transition altitude is referred to as a flight level. So ...
14
votes
6answers
8k views

How does an aircraft descend without its nose pointing down?

I have seen many cockpit videos of airplanes landing, and nearly none of them have their nose down for losing altitude. How does this happen? and how does an airplane, such as A320, descend without ...
2
votes
2answers
80 views

Why is ISA Standard pressure 1013.2 not used for contour charts instead of QFF?

I am confused because QFF being actual mean sea level pressure is subject to change why would we use it for mapping terrain? Does this mean the height of a given terrain changes with the change in QFF?...
1
vote
0answers
26 views

Is there a database from which I can retrieve the Expected Crossing Altitudes of a Departure or Arrival Procedure?

I am stuyding FAA's Coded Instrument Flight Procedures (CIFP) file which uses ARINC 424 digital format to code its data. I noticed that only mandatory crossing altitudes and speeds are included in the ...
8
votes
4answers
1k views

Which altitudes are safest for VFR? [closed]

As a fairly new pilot who does a fair amount of x-country flying I find myself "feeling" safer going East at 5500 and West at 6500 happily burning extra fuel to get up there. Listening to the on route ...
1
vote
1answer
129 views

How is the total drag variation with velocity related to altitude?

Here in the question given I am confused how to relate the altitude with the given plot of total drag and velocity.
3
votes
1answer
214 views

Why does the spool speed increase with altitude for a turbofan engine (single spool & double spool)?

So, I want to see the effect of altitude on the compressor characteristic of a single spool & double spool turbofan engine at constant flight speed and TIT (turbine inlet temp). I am aware that ...
3
votes
2answers
301 views

Why is the B737 altitude display unneccessarily ambiguous?

I was playing FSX again lately and was flying the B737-400. So I hope it is simulated correctly and this question isn't dead on arrival :-) It always bugged me, that the altitude display on the MFD ...
3
votes
1answer
116 views

How do altimeters cope with varying lapse rate?

How do barometric altimeters measure altitude above atmosphere datum if the laps rate of the pressure is not uniform, not constant? Imagine these lines representing pressure lapse rate: ...
2
votes
1answer
95 views

How do flight procedure designers decide when to assign an altitude constraint to a waypoint?

I am studying procedure design manuals (TERPS, PBN 8260.58A manual, ICAO PANS-OPS 8168 manual etc.) and I haven't found any guidelines concerning altitude constraints that can be imposed on a waypoint....
0
votes
2answers
60 views

What is the limit between lower and higher airways in VFR?

On skyvector you see "World high", "world low" and the VFR map. VFR is always under the clouds, correct? But how high do you have to be to follow the high/upper and how high for the low/lower airways?...
29
votes
6answers
4k views

Why cruise at 7000' in an A319?

I was on a flight from Philadelphia (KPHL) to Boston (KBOS), after some delay and some change of route due to weather, the captain announced that we will be cruising at 7000' due to delays in the area....
3
votes
3answers
256 views

Is the transition altitude around Denali still 18 kft AMSL, and, if so, how is this handled?

In North America, the transition altitude - the altitude below which everyone reports their altitude in feet above mean sea level (AMSL) and sets their altimeter to whatever the weather dictates that ...
5
votes
1answer
131 views

How is paint embrittlement countered in high altitude aircraft?

There are cases of aircraft that are not designed for high altitudes that can still fly there and as a result the paint on these aircraft "falls off". Although most aircraft have paint that is chosen ...
2
votes
1answer
237 views

Why is True Altitude calculated using the difference from the QNH to 1013hPa?

I have an example for true altitude calculation. The given Information is QNH: 983hPa, cruise in FL 85, ISA -10°C in this Alt. The math and calculations are not hard and i also get to the correct ...
1
vote
0answers
153 views

Why use turbofan engines for high altitude flight?

I noticed that a lot of high altitude aircraft have turbofans for engines. So I researched and figured out that turboprop engines are more efficient. But most high altitude aircraft like the Global ...
2
votes
1answer
184 views

How do changes in flight affect L/D max and the speed at which I must travel to maintain it?

I have an plane flying at L/D max and I want to maintain L/D max. Firstly, if this plane burns through a portion of fuel and becomes lighter, how would I have to change the speed to maintain it? My ...
1
vote
1answer
256 views

What is the highest a helicopter can fly?

What is the highest theoretical and current flight a helicopter can achieve?
3
votes
1answer
73 views

Why does V165 have two different MEAs over the same route section?

Why does V165 have two distinct MEAs which vary by a large factor (apart from the 180$^{\circ}$ rule of altitudes) considering they would be clearing the same obstacles and receiving signals from the ...
0
votes
1answer
65 views

Identify a change in Altitude based on direction and WCA applied?

Question below is from study material for the EASA PPL license MET course. It's an unlikely question but it's interesting to review. You are flying from west to east with WCA +6°. How is your true ...
1
vote
0answers
71 views

Why does the Hinch Mountain VOR (as an example) have void areas under certain altitudes published in the AF/D?

I was digging around the SE region AF/D, and I was reading KSRB (Sparta, TN), and this "VOR unusable" listing is contained in it: The sectional chart shows that it is nearly on top of a hill. I've ...
2
votes
0answers
32 views

How is The Published Runway Touchdown Zone Elevation Decided?

The touchdown zone of a runway can be up to 3,000 feet long if the information I have is accurate. How is the published Touchdown Zone Elevation determined? Is it the center, an average of the ...
0
votes
2answers
5k views

How can I estimate pressure altitude?

How do I find pressure altitude? Find pressure altitude using rule of thumb for 1498 feet when the altimeter setting is 27.83" Hg. I did (29.92-27.83)*1000+1498=3588 Did I do this correctly?
1
vote
1answer
3k views

Calculation QNE and QNH, with flight level and QNH set lower (higher) than QNE

Hi Student pilot here. Lets say Mr pilot is flying at FL75 and QNH is set at 995 hpa, however there is a mountain in the way at 7000', will he below or above the mountain? If you could visually ...
1
vote
2answers
203 views

Is there a way to code Minimum Enroute Altitude using ARINC 424 file format?

I am studying ARINC 424 file format, and I have noticed that there is not any reserved space for coding Minimum Enroute Altitude (MEA), as far as Instrument Flight Procedures are concerned. I find ...
0
votes
1answer
215 views

How can I figure out critical altitude?

In Vmc situation (minimum speed where pilot can maintain altitude), How can pilot figure out the Vmc? And also, why critical altitude is important to know?
3
votes
1answer
323 views

What is the critical altitude?

What is the definition of critical altitude and why is important to know in Vmc graph? Also, is there any critical altitude in the Piper PA-44 Seminole?
3
votes
1answer
161 views

How are altitudes handled with airports near or above transition altitude?

Transition altitude refers to the altitude above which all altimeters are set to a standard pressure setting (typically 29.92 inHg) instead of to the local surface pressure, and altitudes are given in ...
1
vote
1answer
186 views

Wind vs high altitude cruise [duplicate]

Yesterday I flew back from Tokyo down south against great head wind around 150kt at 34000’, the original flight plan was to cruise at FL240 for a while then climb up, but the captain decided to get up ...
0
votes
1answer
72 views

How much the true altitude will be lower than indicated altitude by 10°C colder?

Aproximately how many perecent the true altitude will be lower than your indicated altitude , if the temperture is 10°C colder than standard ?
5
votes
3answers
508 views

How do pattern and overflight altitudes work for airports underneath Class C airspace?

Lowell City Airport (24C) has an elevation of 700 feet MSL. So normally, the pattern altitude is going to be 1,700 feet, and the altitude for overflying the pattern is going to be 2,200 feet. However,...
11
votes
1answer
404 views

Is there research suggesting that VFR cruise altitude rules improve safety?

In the United States, 14 CFR 91.159 prescribes cruising altitudes for level flight under VFR: (a) When operating below 18,000 feet MSL and (1) On a magnetic course of zero degrees ...
28
votes
3answers
7k views

Was the transatlantic crossing for Concorde too short to reach optimal cruising altitude?

When listening to Gander/Shannon ATC on shortwave, you could hear Concorde communicate its planned flight levels at longitudes from 20 West till 50 West. What I remember is that it would continue ...
5
votes
2answers
187 views

Is vertical separation based on geometric difference or altimeter difference?

In the comments below one of the answers to this question about the influence of temperature on vertical separation, the question was raised whether ATC ensure 1000ft vertical separation based on ...
30
votes
3answers
6k views

Why is 0 ft a valid target altitude for an autopilot?

Inspired by this story; The pilot of a Flybe plane that dropped 500 ft (152m) in 18 seconds had selected the wrong autopilot setting shortly after take-off, an inquiry has found... ...The ...
0
votes
3answers
2k views

What's the difference between flight level and pressure altitude?

When should we say flight level and when should we say pressure altitude? I know they both set QNE 1013.25, but there is a difference between them. Anyone know?
0
votes
2answers
535 views

Maintaining straight and level altitude [duplicate]

just a completely random question that I suddenly thought - doesn't straight and level flight prove that the earth's surface is not a globe? Once cruising altitude is reached, the plane remains at the ...
0
votes
1answer
243 views

Why can't I ever get my right ear to pop on descent in a plane?

Whenever I'm flying, there's a period of descent where my right ear just refuses to pop. This has been bothering me for at least ten years. There seems to be a long stage of descent where my ear is ...
-1
votes
2answers
2k views

Is there a rule of thumb for reading AGL vs MSL? [closed]

Recently, I read that as it pertains to directions: if you read it, it's true, if you hear it, it's magnetic. This is mostly correct, one edge case though is runways are written/drawn with magnetic ...
1
vote
1answer
385 views

Why would a plane drop 14.000 ft mid flight?

Just noticed American Airlines flight 221 dropped 14.000 ft mid flight today. Curious, what could have caused this? Here are the flight details.
0
votes
1answer
791 views

Why do planes fly so high? [duplicate]

It so occurs to me that commercial airliners cruise at altitudes of over 30,000 feet. But why do they fly so high if there are many dangers such as cabin de-pressurization when they can simply fly ...
0
votes
1answer
408 views

Calculating the maximum altitude of a drone [duplicate]

Is there an equation to find the maximum altitude that a drone or quadcopter can fly to ?
0
votes
1answer
499 views

Can a commercial aircraft theoretically reach 60,000ft? [duplicate]

As per this question: Altitudes above 60,000 feet are class E airspace. That means that, if you are lucky enough to have an aircraft that flies that high, once you get there you could ...
5
votes
1answer
791 views

Why would a Mode-C transponder report a different altitude than an altimeter/GPS?

This is related to a small single-engined plane. On a recent flight, the controller kept telling me that I was 300 ft higher than it appeared on my altimeter and GPS (which were in sync). This was ...