Altimeter Setting - [Transition Altitude, QNH and QNE]
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- เผยแพร่เมื่อ 24 ธ.ค. 2024
- Below the Transition Altitude, you have to use as an Altimeter reference the Pressure at the Mean Seal Level also called QNH.
Two Aircraft departing from 2 different airports will use the QNH, however, this value changes from one place to another depending on the Pressure on that area.
So, if you depart from an airport with a specific QNH you must change constantly the altimeter pressure reference in order to keep the Mean Sea Level as a reference.
As you can imagine this is not an easy task.
The Transition Altitude has been established in order to provide you with a clear and specific Altitude where you have to change from the Sea Level Pressure to the Standard Pressure of 1013 hpa also called QNE.
By selecting the QNE you will use the same pressure reference of all the other Aircraft flying above the Transition Altitude.
Using the QNE as a reference you will be flying FLIGHT LEVELS and not Altitudes because you are not using the QNH as a reference anymore.
Why don't we use the QNE all the time then?
Well, you need to use the Mean Sea Level Pressure as a reference until you are clear of terrain.
The terrain is expressed in Elevation which, uses the Mean Sea Level as a reference.
If you want to separate yourself from the obstacles you need to use the same reference.
So, When you take off you must use the QNH until the Transition Altitude then changes to QNE and fly FLIGHT LEVELS.
You can find the QNH from the Atis, metar, ATC.
The Transition Altitude is indicated on the AIP, ATC, ATIS, and IFR charts.
If you want to know more about IFR training watch the video below:
IFR introduction: • IFR TRAINING (Part 1) ...
SIDs: • Standard Instrument De...
STARs: • Standard Arrival Route...
Approach Chart: • Jeppesen Approach Plat...
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Disclaimer:
THIS VIDEO IS FOR ENTERTAINMENT PURPOSES ONLY.
NOT FOR REAL-LIFE OPERATIONS.
PLEASE REFER TO THE OFFICIAL MANUAL AND DOCUMENTATION.
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![QNE Is Not A Pressure Reference -[What exactly it is and why do we use it during flight Operations].](http://i.ytimg.com/vi/a7odxOsZDuQ/mqdefault.jpg)
![QNE Is Not A Pressure Reference -[What exactly it is and why do we use it during flight Operations].](/img/tr.png)
![Pressure Altitude - [What it is, How to calculate Pressure Altitude and why is it important??]](http://i.ytimg.com/vi/rvmoJ2rQIG8/mqdefault.jpg)
If you any question regarding the Transition Altitude leave a comment below and I will Naswer you! Happy Landings...
The clearest explanation that I have ever found on the internet!
Thanks for watching and the comment!! Don't hesitate to ask me any questions when watching the rest of the videos! 👍
agree
Very clear explanation, and very clear English accent, I'm very thankful
Best explanation sir ,i was searching for last 3 days but now got everyone clear
Bravo; you have made this concept very easy to understand without complicating it like most other TH-camrs do. You have for sure gained another subscriber...keep up the great work and I will start watching your other videos.
Thanks for watching!! I'm glad to read this!
best explanation ive ever gotten on the internet!
Many thanks for watching and the kind comment! Have a great day!!
Best and easiest explanation out there!
I'm glad you liked the video!! Many thanks for watching🙏
Best and simplest explanation found on youtube till now!! Thnku sir for this amazing support!!😊😊
You are very welcome!! My pleasure
ı am training and preparing for turkish airlines F/o asssestments with your videos. . thx a lot mate. you are a legend . thx a lot.
I'm glad to see that my effort is helping you! You are very welcome
Thanks for the video, I was struggling to understand this but you made it very clear!
You are very welcome!! Glad the video helped
As I read from some other source they said that " is different to the other altimetry Q codes in that it is an altitude not a pressure ". Would you like explain this, tks.
Hey, many thanks for watching.. are you referring to the QNE?
@@PILOTCLIMB yes
WONDERFUL PRESENTATION. I fly Cessna-172 in Vermont. A comment that I would like to make is that usually private pilots know the 29.92, which is the same as 1013 hPa. At the beginning I got confused. Your explanations are superb. Thank you.
Many thanks for your comment! I'm glad to read that you liked the video
Thank you Gabriel, I will add this to my watch list for another view.
You have earned my subscription ✌️
You are welcome!!! I'm very happy to have you on-board! Let me know if you have any questions when watching the rest of the videos! I wish you a great day!!
@@PILOTCLIMB yes sure, thank you.
Im going for my UK NPPL for now, all I'm after is a little bush plane which I should hopefully be able to hop down to the South of France and Portugal.
Your explanations have cleared up a few things before one of the exams ✌️
@@ThePikeywayne that's great!!
Hi Gabrielle, I have a question: in approach charts, usually the transition level is not provided, they say "transition level by ATC" and the chart only informs a transition altitude. However, when descending, we need to change our altimeter back to the local QNH at the transition level, is that right? In that case, if we are not flying online or if there is no ATC online, is there a way to calculate the transition level from the transition altitude?, to make sure our simulation is done correctly? Thanks!
Hey, many thanks for watching! Yes you are correct! You can calculate the TL from the TA, however you need to know what is the transition Layer used at that airport.. usually is 1000feet. Let me know if you have more questions
Thanks a lot captain ....this one was really really useful.
You are very welcome!!
So QNH is changing because mean sea level may rise up or down and because of that we use QNH to have the mean sea level altitude so we can have the correct altitude for example for ILS approach so it counts correctly. But flying in simulator where water sea level pressure does not change have not affects and leads me to landing very low during ILS. So I should use QNE all times in simulator when you have no weather set.
In reality once you are on the ILS the QNH should be irrelevant. Check my latest video where I explain this
Excellent explanation! I just subscribed.
Welcome on-board!! I'm glad you liked the video!! Have look at the channel you might find something interesting and, let me know if you have any questions when watching the videos! I wish you a great day!
Good Job brother keep it up
looking forward to more videos
Hey, I'm glad you liked the video!! Have a look on my channel there are many videos.. next one this Friday!! I wish you a great day!!
Great video, thank you.
Question: I understand the reason for using QNE. But, let's say that an airliner is flying at FL400 from NY to London. And let's say that as the flight progresses over the Atlantic, there are multiple High pressure and Low pressure systems over the ocean. So, the QNH down below is changing. Would that mean that the actual altitude above MSL for the airplane is also changing? If so, I guess it means the autopilot is descending and then climbing the airplane to maintain the FL400 and to account for local altimeter pressure levels? Is that right?
You are very welcome, that correct, but that's fine since all aircraft are using the same reference
Bro thank you so much! I got what I looked for! God bless!
You are very welcome!
Thanks for all the videos.
For IFR flights above the Transition Level, will the autopilot for all the aircrafts in flight be required to pick up the needed altitude from the altimeter or could some airplanes be using GPS based altitude? If so, are there any other flight parameters for the autopilot that are not allowed to come from the GPS?
You are very welcome! The Altitude is based on the Altimeter.. The GPS altitude could be used as a reference for some nn procedure
Why the transition altitude in some of airport is different? I.e from airport A transition alt is 10.000 and from airport B transition alt is 13.000? Thank you
Hey, thanks for watching! Most probably the Terrain in the areas of the airports that you mentioned are different. Higher terrain higher Transition Altitude. Let me know if you have more questions
Sir qnh means atmospheric pressure at mean sea level then how different aerodrome have different QNH
Hey, many thanks for watching! The Airports have different QNH because the pressure at the mean sea level changes from place to place. It is not a constant value. Let me know if you have more questions.
when landing we must change from qne to qnh on the TA?? please make a video for the landings..thank you captain
Hey, thanks for watching!!
During descend you change from the standard 1013 to the local QNH when passing through the Transition Level.
I will make a practical video soon.
A little note about the video.. Commonly we refer to QNE as a pressure reference, however if you really want to be precise the QNE is the difference in feet that there is between your aircraft and the standard 1013hpa.
Check the following video about the QNE definition I made:
th-cam.com/video/a7odxOsZDuQ/w-d-xo.html
Let me know if you still have any questions..
I wish you a great day!
Gabriele
Pilotclimb
Hey there, I hope you are doing great!
I'm uploading a video about the Transition Level!
I wish you a great day!
Gabriele
Pilotclimb
I hope you are doing great!!!Thank you very much!!!!
Thanks a lot, very interesting and comprehensive explanation!
Hey, many thanks for watching and the comment!! Let me know if you have any questions..have a great weekend
Слава Украине!
QNE is also the "STD" on the Barometer correct?
Correct!
Very helpful and well explained. Many thanks, Pilotclimb.
Hey Mike.
I hope you are doing great!!
Many thanks for watching the video!!!
I'm very happy it helped you out!!
Don't hesitate to ask any questions you might have when watching the videos!!!
I wish you a great weekend.
Gabriele
Pilotclimb
@@PILOTCLIMB Great, thanks, Gabriele. This time I was looking specifically for Transition Altitude but I see that you have many more videos. I'll work my way through them. Thanks, again. Best wishes, Mike
Hii
I have a doubt
When do i change from QNH to QNE in case i am not climbing/ crossing Transition Altitude and when do i change back to QNH (while going to another airport with different Transition Altitude/ Level)
In that case you should respect the transition level/altitude of the areas your are flying.. the ATC will help you with that
Thank you very much for your great explanations ✨🙏✨
Ottimo , grande video. Grazie mille !!
great work , cheers fella
Many thanks for watching and the kind comment!!
Thanks for the explanation. My question is Why we use QNH most of the time for landing and not QFE?
Hey, thanks for watching!! I hope the video helped you..
We use QNH during landing and descend because all the minimum altitudes (that we have to respect in order to maintain the terrain separation) take as reference the mean see level.
So you want to use the same reference as the minimum altitude and the terrain elevation in order to keep the separation.
Let me know if I answered the question.
Have a great day
@@PILOTCLIMB Hi thanks for the reply..!!
So if the obstacles are reffered wrt QFE in that case QFE can be used?
@@ravindrakeshkar1518 You are welcome.
It is important to understand what pressure reference your destination airport uses for landing.
I have been flying in Europe for more than 15 years and I have only used the QNH for landing.
The QFE is used in some countries (very rare) and to perform altimeters tests.
@@PILOTCLIMB Understood Sir..!!
Just wanted to understand the concept why QFE is not used often. Is it to standardize everywhere or does it have any other impact
@@ravindrakeshkar1518 You want to use the QNH to make sure that we use all the same pressure for that area and, on top of that, since the terrain elevation is measured from the mean sea level you want to use the same reference to be able to separate yourself from the terrain.
Hi hope you are good.
I have a big list of interesting question for you pilot. Answer as much as you wish…
1. Who gives use trans level when it varies (atc , atis ,,any others)
2. Trans alt is fixed for countries . How do they calculate it ?
3. What is the maximum thickness of transition layer.
(the answer should highlight the importance of having the layer and not only 1 level reference but a layer...)
4.What are Common trans alt for some countries
5. Transition layer only climb and descent we never cruise there.Its not common for atc to say maintain FL or atltitude inside transition layer ( but if they ask maintain we should maintain... )but my question is that they ususally dont cruise there true... since we wanna climb and descend . And if controller said maintain a flight level or altitude in between the layer… it would be risk if no horizontal separation of aircraft also it would be risk if airclafy arf flying or descending around it true…
6.Why don’t all countries have the same transition altitude.
7. Is there a benefit of decreasing this transition altitude .I mean in Lebanon transition altitude is 13,000 ft while in germny transition altitude is around 5,000 ft.
8.Can we have sps standard pressure system 1013 hpa =qne at local conditions = qnh is it possible?
9.Whats if passing throght a surface inversion ? wouldn’t local presuure change.. would atc know or atis know if a surface inversion suddenly happened...
10.How many times do we usually change qnh : local pressure while climbing? While descending?
11.Who uses qfe the field of the pressure ? Russia? Airshows close close to the ground or even sometimes airlines to cross check things?
12.How is transition altitude determined? ( also note that Denali Mountain in USA is higher than trasn alt 18,000ft) (hmm i though trans alt should be clear of all obstacles)
13.What about the horizontal and vertical separation in transition layer? How is this done? Do different countries have different regulations and procedures for this?
14.What if it’s a busy airport like London heathrew airport and trans alt is low maybe I belive it's 3,000 ft .
15.1013.25 or 1013? Doesn’t it make a difference? Cant this rounding cause errors or accidents?
16.What is the relation between 1hpa = 27 ft around 9m …Is this number always constant ... shouldn't it vary with temperature or pressure?
17.If its foggy isn’t qfe field pressure better than qnh local pressure … also can you land if its extremely foggy and cant see anything?
18.There is an instrument in cockpit called radio altimeter (I n cat 2 or 3 ils) that works below 2,500 ft maybe that reads height (above that its doenst show )....it shows only in cat 2 or 3 but does it need the pressure as well?
19.What are rounded to 1000 ft and what are rounded to 500 ft ( trans alt and trans level)
20.How do you find qnh if you don’t have a control tower or traffic?
21.Do some counties have a fixed transition level ?
21.What if a country has many airports? Do they all have the same trans alt? same trans level ? hmm?
22.While descending some pilots put qnh long before reaching transition level ? hmm ?why? isn't this risk? Or im mistaken they apply qnh at tranition level ?
Many thanks for your great comment... Your questions are great, As I mentioned most probably I'll make a video about that..
@@PILOTCLIMB Hi again mate, will you be able to do a video about the questions you told me were great... Or you are busy mate these days...:) love ya!
It was helpful thanks
You are very welcome!
it was really helpfull.. you are amazing at teaching.. i wish i had you as my teacher.. thank youu sir.. 👍🏼👍🏼
You are more than welcome!! Many thanks for you kind support!! Don't hesitate to ask me any questions when watching the rest of the videos. I wish you a great day!
Your videos helps me alot.....Thank you Captain 😊😊
I'm very happy to read that the videos are helping you!!! Don't hesitate to ask me any questions when watching the rest of the videos!!
Is QNE the same as SPS
I'm not familiar with SPS
I love Italian accent in English
Amazing man , I enjoyed the speaking more than explanation 😉.
A320 tutorials if you don’t mind
Capitano 😘
Glad to read you like the videos!! And my accent 😂.. I'll take your suggestion into consideration for a future content..
Nice sir, can u upload video on RNAV and RNP
hey, I hope you are doing great! Many thanks for watching!
I will do videos about the RNAV/RNP in the next future.
Happy New Year!
Gabriele
Pilotclimb
Very nice video sir ❤❤
Thank u
You are welcome! Have a great day
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