Types of altitudes

Types of altitudes

TYPES OF ALTITUDE:

 

•  Indicated. It is read directly from the altimeter. If it is set with the QNH, the indicated altitude will be approximately equal to the altitude of the airplane above mean sea level (MSL).

Altimeter

         QNH : It is the preassure at see level Altimeter, flight instrument, QNH, PA

Altimetry

Altimetry, differences of QNE, QNH and QFE

• Real Altitude , or actual altitude, is the actual altitude above sea level. The altitude of airports, mountains, obstacles, etc. The altitude shown on charts are given in true altitude.

• Pressure Altitude (PA) . Altitude read when the altimeter is set to  QNE (  the altimeter scale is 1013).

altimetry

pressure altitude, true altitude, absolute altitude

in other words we have ISA atmosphere, which was created by engereers ( check the post International Stantandard atmosphere ), that atmosphere has some predetermined values shown in the picture below 

ISA values of Preassure and altitude

So when the atmospheric pressure is 22.22 in. Hg the pressure altitude is 8000 ft , so each time we have an outside pressure of 22.22 in.Hg,  our PA is 8000 ft . Which only will be the same of our true altitude in  case of the values of the atmosphere are completaly the same as I.S.A values ( very difficult to happen).

Imagine this situation you are about to take off in a 2000 ft height field, and your atmospheric pressure it is 20.57 in. hg. So in this case our true altitude would be 2000 ft , however our PA would be 10.000 ft.

To conclude the PA is the atmospheric pressure expressed in terms of altitude ( ISA Altitude)

  Why is PA so important ?

Because it is used to calculate  the next altitude, called density altitude. It is a way to find out how an aircraft behaves against an event , for example for calculating the runway lenght you need for taking off, as you can see in the image bellow.

performances take off chart
• Density Altitude (DA). It is the Pressure altitude Corrected by non-standard temperature deviation. As you can see it is the first part of the performance chart shown above.

take off performance chart

 

The concept is the same as PA in the way that dependending on the external density our DA changes for example :

International Standard atmosphere table

 

Imagine we are about to take off from a 2000 ft height field which density is 0.9428 our DA would be 2000 ft , because the density of our true altitude  is the same as the I.S.A density ( check the table above). If the density would have been  0.7620, our true altitude is still 2000ft , however our DA is 9000ft .

Why it is so important the DA ?

As we know DA is related to our exterior density, and the density is related to the mass of the fluids ( density = mass/volume). So if we have a big air density, we have big mass of air. If we have a big mass of air the engine works better  , the flight controls works better ….. . Due to is possible to move more amount of air .

To conclude : the bigger is the atmospheric pressure and density the lower the PA and DA are ( check the tables above), so the aircraft behaviour is better.

 

 

Comentarios

  • 선릉야구장 | Ago 1,2017

    I do believe all of the ideas you’ve offered to your post.
    They’re really convincing and can definitely work. Still,
    the posts are too short for starters. May just you please lengthen them a bit from subsequent time?
    Thanks for the post.

  • 선릉야구장 | Dic 10,2017

    I absolutely love your blog and find a lot of your post’s to
    be just what I’m looking for. Do you offer guest writers to write content
    available for you? I wouldn’t mind writing a post or elaborating on most of the subjects you write
    with regards to here. Again, awesome web log!

  • 선릉야구장 | Dic 23,2017

    I’ve been surfing online more than three hours today, yet I never discovered any
    fascinating article like yours. It’s beautiful price sufficient for me.
    In my view, if all website owners and bloggers made good content
    as you probably did, the internet will be
    much more useful than ever before.

  • 선릉야구장 | Abr 9,2018

    Oh my goodness! Amazing article dude! Thanks, However I
    am experiencing troubles with your RSS. I don’t know the reason why I cannot subscribe
    to it. Is there anyone else having similar RSS issues?
    Anyone who knows the solution will you kindly respond?
    Thanx!!

  • 선릉풀싸롱 | Abr 10,2018

    Thanks for the good writeup. It in fact used to be a amusement account it.
    Look complicated to more added agreeable from you! By the way, how could we keep in touch?

  • 강남풀살롱 | Abr 11,2018

    Greetings! Very useful advice in this particular post!
    It’s the little changes that will make the most significant changes.
    Thanks for sharing!

  • 강남야구장 | Abr 30,2018

    Article writing is also a excitement, if you know after that
    you can write or else it is complex to write.

  • 역삼풀싸롱 | May 3,2018

    I like what you guys are up too. This kind of clever work and reporting!

    Keep up the wonderful works guys I’ve included you guys to my
    personal blogroll.

  • 강남풀사롱 | May 3,2018

    Yes! Finally someone writes about 선릉야구장.

  • 강남야구장 | May 8,2018

    Your mode of explaining all in this post is actually nice,
    all be able to effortlessly know it, Thanks a lot.

  • 선릉풀싸롱 | May 9,2018

    Keep on writing, great job!

  • 강남풀싸롱 | May 13,2018

    Spot on with this write-up, I seriously believe that this
    site needs far more attention. I’ll probably be back again to see more, thanks for the info!

  • 선릉야구장, | May 14,2018

    Hi, I want to subscribe for this blog to get most recent updates, thus
    where can i do it please help out.

  • suba analuba | Ago 12,2018

    BPECm4 This is really interesting, You are a very skilled blogger. I ave joined your rss feed and look forward to seeking more of your great post. Also, I have shared your website in my social networks!

  • 강남매직미러 | Ago 14,2018

    Good way of explaining, and nice article to take information concerning my presentation focus, which
    i am going to present in academy.

  • 강남풀싸롱 | Ago 21,2018

    This design is steller! You most certainly know how to keep
    a reader amused. Between your wit and your videos, I was almost moved to
    start my own blog (well, almost…HaHa!) Excellent job.
    I really enjoyed what you had to say, and more than that, how
    you presented it. Too cool!

  • 선릉야구장 | Ago 22,2018

    Useful information. Lucky me I found your website accidentally, and I’m shocked why this accident did not came about in advance!

    I bookmarked it.

  • 강남매직미러 | Ago 22,2018

    I pay a quick visit everyday a few blogs and websites to read articles,
    however this web site offers feature based writing.

  • 강남풀싸롱 | Ago 24,2018

    Aw, this was a really good post. Taking a few minutes and actual effort to produce a great article… but what can I say… I procrastinate a lot and
    don’t seem to get nearly anything done.

  • 강남야구장 | Ago 25,2018

    Hi my family member! I want to say that this article is amazing,
    nice written and come with approximately all vital infos. I would like to peer more posts like this .

  • 역삼야구장 | Ago 27,2018

    No matter if some one searches for his required thing,
    therefore he/she wishes to be available that in detail,
    thus that thing is maintained over here.

  • 강남풀사롱 | Ago 28,2018

    Wonderful goods from you, man. I have be mindful your stuff prior
    to and you are just too great. I actually like what you’ve acquired right here, certainly like what you’re
    saying and the way during which you assert it. You’re making it
    entertaining and you still take care of to keep it wise.
    I can’t wait to learn far more from you. That is
    really a tremendous website.

  • 선릉풀싸롱 | Ago 29,2018

    Just desire to say your article is as astonishing. The clearness
    to your publish is simply cool and that i could assume you
    are a professional in this subject. Well along with your permission let me to take hold of your feed to stay up to date with imminent post.

    Thanks 1,000,000 and please keep up the rewarding work.

  • 강남매직미러 | Ago 29,2018

    Pretty nice post. I just stumbled upon your blog and wished
    to say that I’ve really enjoyed surfing around your blog posts.
    After all I’ll be subscribing to your feed and I hope you write again very soon!

  • 선릉풀싸롱 | Ago 31,2018

    Thank you for sharing your thoughts. I truly appreciate
    your efforts and I am waiting for your next write ups
    thanks once again.

  • 역삼풀싸롱 | Ago 31,2018

    I simply couldn’t leave your website prior to suggesting that I extremely loved the usual info a person supply in your visitors?
    Is going to be back steadily in order to inspect new posts

  • 강남야구장 | Ago 31,2018

    Way cool! Some very valid points! I appreciate you writing this post and
    the rest of the website is also really good.

  • 강남풀싸롱 | Ago 31,2018

    Everyone loves what you guys tend to be up too. This type of clever work and reporting!
    Keep up the good works guys I’ve incorporated you guys to my
    blogroll.

    • Hulk1984 | Sep 1,2018

      thank you very much

  • 강남풀사롱 | Sep 1,2018

    I think this is among the most vital info for me. And i am glad reading your article.
    But want to remark on some general things, The website style is ideal,
    the articles is really excellent : D. Good job, cheers

  • 선릉풀싸롱 | Sep 1,2018

    Hello, Neat post. There is a problem together with your website in web explorer, could check this?

    IE nonetheless is the marketplace chief and a large component to
    people will leave out your great writing because of this
    problem.

    • Hulk1984 | Sep 1,2018

      I will do my best!! thak you for telling me!

  • 선릉야구장 | Sep 4,2018

    Attractive section of content. I just stumbled upon your weblog and in accession capital to
    assert that I get actually enjoyed account your blog posts.
    Anyway I will be subscribing to your augment and even I achievement you access consistently rapidly.

  • 역삼풀싸롱 | Sep 5,2018

    Greate article. Keep writing such kind of info on your blog.
    Im really impressed by your blog.
    Hi there, You have performed a great job.
    I will certainly digg it and in my view recommend to my friends.
    I’m sure they will be benefited from this site.

  • minecraft | Sep 10,2018

    Amazing! This blog looks just like my old one! It’s on a totally
    different topic but it has pretty much the same page layout and
    design. Great choice of colors!

  • 강남야구장 | Sep 11,2018

    I think everything wrote was actually very reasonable.
    But, consider this, suppose you were to write a killer headline?
    I am not suggesting your information isn’t good, however suppose you added something that
    makes people desire more? I mean become a pilot, ATPL theory,
    density altitude, performances, flight academy,altimetry is a little boring.
    You might look at Yahoo’s home page and note how they create
    article headlines to grab viewers to click. You might try adding a video or a related pic or two to grab readers interested about what you’ve got to say.
    Just my opinion, it would make your posts a little livelier.

    • Hulk1984 | Sep 11,2018

      thank you for the advise!! I will do my best

  • minecraft | Sep 11,2018

    Hey there! Someone in my Myspace group shared this site with us so I came to look it over.
    I’m definitely loving the information. I’m bookmarking and will be tweeting this to my followers!

    Terrific blog and wonderful style and design.

  • minecraft | Sep 12,2018

    Generally I don’t learn article on blogs, however
    I wish to say that this write-up very compelled me to try and do it!
    Your writing style has been surprised me. Thank you, very nice post.

  • minecraft | Sep 13,2018

    Wonderful work! That is the type of info that are supposed to be shared across the
    internet. Disgrace on the seek engines for no longer positioning this publish upper!
    Come on over and talk over with my web site .
    Thank you =)

  • minecraft | Sep 15,2018

    Thanks for sharing your info. I truly appreciate your efforts and I am waiting for your next post thank you once again.

  • minecraft | Sep 16,2018

    Its like you read my mind! You appear to know a lot about this,
    like you wrote the book in it or something.
    I think that you can do with some pics to drive the message home a bit, but instead of
    that, this is magnificent blog. A fantastic read.
    I’ll definitely be back.

  • 선릉풀싸롱 | Sep 17,2018

    Nice post. I was checking continuously this blog and I am impressed!
    Extremely useful information particularly the last part
    🙂 I care for such information a lot. I was seeking this particular information for a very long
    time. Thank you and good luck.

  • minecraft | Sep 21,2018

    Hello very cool web site!! Man .. Excellent ..
    Wonderful .. I will bookmark your blog and take the feeds also?
    I’m glad to search out so many helpful information here in the submit,
    we want develop extra strategies in this regard, thanks
    for sharing. . . . . .

  • minecraft | Sep 22,2018

    Very nice post. I just stumbled upon your weblog and wished to say that I’ve truly enjoyed surfing around your weblog posts.
    In any case I will be subscribing to your
    rss feed and I hope you write once more very
    soon!

  • Deja un comentario

    Tu dirección de correo electrónico no será publicada. Los campos obligatorios están marcados con *

    Name*

    Email

    Website