No announcement yet.

DME accuracy question

  • Filter
  • Time
  • Show
Clear All
new posts

  • DME accuracy question

    Hello Alex,
    Can you confirm whether question 1 of 'exam 5 brushup course' is correct or am I missing something?

    The design requirements for DME stipulate that , at a range of 100nm, the max systematic error should not exceed:
    a) + or - 1.5nm
    b) + or - 3nm
    c) + or - 0.25nm
    d) + or - 1.25nm

    Answer given as correct is (a)

    I was under the impression that accuracy had to be either 0.25nm or 1.25% in slant range. How do we get 1.5nm?


  • #2
    It's 1/4NM PLUS 1.25%, nor 1/4NM or 1.25%. That means that at 100NM its 1/4NM + 1.25NM = 1.5NM


    • #3
      DME accuracy...

      Hi Alex,

      This one just caught me out too! Is it worth changing the word 'and' to 'plus' on page 10.3 of the R Nav notes in your next edition?

      Then again, we don't make it too easy for everyone else!!



      • #4
        DME Accuracy

        Hello Guys,
        is there a chance, that the stated accuracy for the DME is not 1,25%+ 0,25 NM, but 0,5NM OR 3%? I'm really confused right now, because, the software we are using for preparation says, it is 0,5NM or 3%. But I cannot visit, neither I would find the right document I guess.
        Has anybody heard anything about this other stated figures in concern to the accuracy?
        With best regards
        Tobias from Intercockpit, Germany


        • #5
          It used to be 1/2 NM or 3%, whichever greater, for the old UK exams. It is now, very definitely, 1/4NM plus 1.25% to match ICAO. I thought Intercockpit students used our software - please tell me this didn't come from there?


          • #6
            Hi Alex,
            thx for your quick reply. You're right, the informations about 1/2 or 3% are not from Jals/Bristol material. I found it in an "old" folder of a friend of mine. This folder was used for study in a different school not long ago (the also use it right now). The thing, that makes me confused is, that the prepware we use for our final test has - in an older question database - the 1,25% + 0,25NM right, but now they changed over to 0,5 or 3% in the new database.
            Let's imaginge, when we go there down to Braunschweig, and take our exams? What is the right answer down there? The new prepware-software one (which includes information of the other learning materials) or the 0,25+1,25 thing. This is something, that makes me angry, a lot of sh** happens like this.
            Can anybody tell me, why you have to pay, if you want to download the annex 10 of ICAO documents? This would give a definit resolution of the thing!
            With best regards


            • #7
              Paying For Your Right To Know

              I want to add to that last line about having to pay. The FAA website provides tons of information without your having to pay anything. I wonder why ICAO,CAA,and JAA cannot follow their example. This is not only from any exam point of view. But it does help to know the latest from the horse's mouth by way of their Advisory Circulars etc. This is only a suggestion.


              • #8
                "Can anybody tell me, why you have to pay".

                ha ha. because its the CAA. you pay for EVERYTHING.


                • #9
                  You have to pay......unless you know the web address for the Danish CAA (Gawd bless 'em)


                  • #10
                    Hi Alex,
                    Thanks a lot. It is like a Diwali gift. Best wishes.