A "Busy" Wish

[earl1937]

  Well, since no one has anything else to do, try a little education! Describe "Magnetic Lines of Variation" and what effect does this have at AH headquarters in Texas?

[Myg]

Haha, sounds like another idea for the O'club: Quizzes! 

[bustr]

True Earth rotational axis North, versus Earth's magnetic fields North.

Magnetic North varies from region to region due to variances in the earth's magnetic fields. It's why hikers get lost even using a compass. Modern topo and flight maps show regional declinations. Without todays GPS system. Good Navigators were once worth their weight in gold.

Hey Lucy this don't look like your mommas house. You did say due north for 3 hours as the vulture flies..........

[Arlo]

Well, since no one has anything else to do, try a little education! Describe "Magnetic Lines of Variation" and what effect does this have at AH headquarters in Texas?

Does Scotch have magnetic qualities other than outright attraction?

[kvuo75]

http://en.wikipedia.org/wiki/Magnetic_declination


http://www.ngdc.noaa.gov/geomag/img/DeclinationMap_US.png

about 5 degrees east for dallas.

[earl1937]

http://en.wikipedia.org/wiki/Magnetic_declination


http://www.ngdc.noaa.gov/geomag/img/DeclinationMap_US.png

about 5 degrees east for dallas.

:airplane:You air are correct! Didn't think I would get many response to the question! Most people go through life thinking that the compass points at the North Pole! Little do they know that what the magnetic compass points at is about 700 miles away from the North Pole. (Think that mileage is close on distance, but really can't remember for sure).

[kvuo75]

and its moving too

[earl1937]

and its moving too

Not sure what you are referring to by "moving", as the "true North Pole" and the magnetic pole has been in the same places for millions of years!

[kvuo75]

Not sure what you are referring to by "moving", as the "true North Pole" and the magnetic pole has been in the same places for millions of years!

the magnetic pole moves quite a bit. constantly in fact.


apparently about 41km a year.

http://en.wikipedia.org/wiki/North_Magnetic_Pole

[pembquist]

and then once in a while it flips end over end, which is why you can tell the sea floor is spreading

[earl1937]

the magnetic pole moves quite a bit. constantly in fact.


apparently about 41km a year.

http://en.wikipedia.org/wiki/North_Magnetic_Pole


(Image removed from quote.)

Good answer! Just remember, the mineral deposit which attracts your compass is, as I indicated, in a fixed position in the earth, but as the earths magnetic fields ebb and flow thu time, as your chart indicates, the actual magnetic field moves. Good answer though and thanks to GPS and other navigational aids in todays aviation industry, we don't have to worry with figuring plus or minus when navigating.

[kvuo75]

it still means something enough to the FAA that they still put it on the terminal procedures airport diagrams

[earl1937]

it still means something enough to the FAA that they still put it on the terminal procedures airport diagrams


(Image removed from quote.)

:airplane:Your point is correct, but the reason they do is if your have complete electrical failure and don't have a Ipad or notebook with you that has that ILS system in it, then you gotta do it the old fashioned way!

[Stellaris]

?? Why wouldn't everyone know this?  Map and compass is taught in grade 7, and beyond that, half the people on this forum are licensed pilots.

[kvuo75]

:airplane:Your point is correct, but the reason they do is if your have complete electrical failure and don't have a Ipad or notebook with you that has that ILS system in it, then you gotta do it the old fashioned way!

that doesn't make any sense.  
 
how would knowing true heading help with an instrument approach in an emergency.. all the bearings on an instrument approach are magnetic, all headings given by atc are magnetic.

and also, I've never heard of an ipad or notebook with an ILS receiver (have seen handheld vhf's with VOR mode tho) --  maybe you mean GPS. Even so, those headings are magnetic also.