How to solve Polar Stereographic problems involving Grid Navigation using geometry. Google 'Cat3C i Books' for hundreds of practice questions with explanations and diagrams.
This just makes me feel like I'm on the wrong school to take my cplh ....many thanks for sharing this amazing explanation! It makes more easier to understand the polar charts!
I think from the entire Gen Nav course, excercises concerning grid nav are a pain in the ass . Luckily with this simple explanation it became a little less pain in the ass :-)
This is far the best explanation available! I use Aviation Exam for q.practice and directly go to check your website if would be able to combine together AE and Cat3C for better results in my exams. Technical parts and memo topics like Air Law I find. Ot so difficult, but G.Nav is another cup of tea!
One proposal is to remove PS and Grid but (a) the proposal has not been passed yet and (b) as you rightly say, those LO's are not due for implementation until 2018 at the earliest. They are still coming up in exams - it never ceases to amaze me how "I didn't get any PS questions" becomes "They've stopped using PS questions" within a matter of hours of an exam. :-) Considering how easy PS questions are - they are only isosceles triangles - I would rather see an exam full of PS questions than a multitude of Lambert's convergency questions, complex time (sunrise to UTC to standard) questions and confusing altimetry questions with ambiguous conversion factors...27 ft, 30 ft, from QNH datum, QFE datum or 1013???? Whatever is removed may be replaced with something worse - that is exactly what happened in 2012. 54 questions in 2 hours to 60 questions in 2 hours, with a batch of approx. 6 simple general knowledge questions replaced by 12 calculation questions..... with no additional time. Be careful of what you wish for.
amazing explanation but it s quite complicated for some people! my point of view is that you need only the sketch, the points and the protractor whick is align on the 180 Meridian
Great explanation is just that the most confusing part was the anti meridian calculation of which convergency is calculated by 20 degrees different between true track and grid north
Hi, this may sound stupid but what if the question was replaced with the North Pole instead of South Pole, is there any difference to solve the question?
Yes, of course. The Greenwich Meridian (GM) runs upwards from the bottom edge of the circle to the centre of the circle (the North Pole). Easterly and westerly meridians are then measured right and left (respectively) from the GM. It is very important to understand the difference between the views of the northern and souther hemispheres, just as important as it is to understand the relationship between westerly and easterly meridians when viewed in relation to the GM or when viewed in relation to the W/E180 meridian. *Looking at GM = westerly on left, easterly on right *Looking at W/E180 = westerly on right, easterly on left The best thing you can invest in for this is a small globe (that you can draw on with whiteboard markers).
Still I am a bit confused once the q.says Grid North is aligned with Greenwich meridian (N.Hem) and the GN is aligned with 180meridian (AE q.16227) and once it says “aligned with Greenwich meridian” on Southern Hem. and the GN is aligned with 000deg. (AE question 51828). Any suggestions? Except that it is clear, just sometimes it makes 180deg difference.
The Grid can be aligned with either the Greenwich Meridian or the W/E180 meridian, in either the southern or northern hemisphere. The simple rule is Grid = Greenwich - Grid North = Up (the page), Grid = W/E180 - Grid North = Down (the page).
Thank you for fast reply. So basically once the question say GN aligned with the Greenwich Meridian the GN is towards the top end of paper on both S/N hemisphere but I just use the rule South Hemisphere 000 up page, North Hemisphere 180up the page. Is that just only so simple?
@@brokozor Yep, that simple. The biggest problem I find is that people get the orientation of the northern and southern hemispheres mixed up. ALL meridians point outwards from the South Pole and inwards towards the North Pole. The Greenwich Meridian always points UP the page and the W/E 180 meridian points down the page. What you must remember is that, in the northern hemisphere the North Pole is the centre of your circle and the GM points upwards from the bottom edge of the circle into the centre of the circle; in the southern hemisphere the South Pole is the centre of your circle and the GM points upwards from the centre of the circle (away from South) to the top edge of the circle (towards North).
What is the limitations of this projection. .... Answer . The complete hemisphere cannot presented because equator infinite. . This answer right or wrong . Can u tell me.. Plz
We are only concerned with the requirements of the EASA syllabus so we don't go into the full limitations of a stereographic projection. For the purposes of the EASA syllabus, the 'usable area' limitations of the Polar Stereographic chart are from N70 - N90. Although this is limited to an azimuthal PS chart which has its origin at the pole itself. The Polar Stereographic projection provided in the Jeppesen GSPRM "cuts into" the Earth at N75, and would have a usable area from the pole down to approx. N60 (although these properties are not examined)
The Grid Datum Meridian (GDM) will be stated in the question. Any meridian can be the GDM, although, from experience the examiner has only used the 000 and 180 meridians in the exam questions. Hope that helps. :-)
great I see.. can you take a look at this? a route is drawn from (75 N 60 E) to ( 75 N 30 W) on a polar Stereographic chart with grid aligned with the greeenwich meridian. The Grid Track (GT) is... and how come the initial True course is 360 -45?
