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Shift of Earth's magnetic north pole affects Tampa airport


Doering

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Halifax used to be 15/33 & 06/24

The variation is changing very quickly now. Makes one wonder why, with all the GPS and PBN around the world, right down to the Aeronca Champ at a private field, we still rely on magnetic north as a datum.

Should the magnetic references be removed from aviation?

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Should the magnetic references be removed from aviation?

Blasphemy, I say.

You're suggesting that we should give up a completely free, absolutely fail safe backup system that changes in a predictable way (maybe 2 degrees every 100 years (less in most areas of the world)) for an electronic system that resides in a hostile environment, just one sunspot away from destruction and controlled by a single government.

Next someone will be suggesting that FMS and autopilots are so reliable and can be controlled from the ground, so we don't need pilots. :unsure:

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Air navigationEarth_Magnetic_Field_Declination_from_1590_to_1990.gifMagnetic declination has a very important influence on air navigation, since the most simple aircraft navigation instruments are designed to determine headings by locating magnetic north through the use of a compass or similar magnetic device.

Aviation sectionals (maps / charts) and databases used for air navigation are based on True north rather than magnetic north, and the constant and significant slight changes in the actual location of magnetic north and local irregularities in the planet's magnetic field require that charts and databases be updated at least 2 times per year to reflect the current magnetic variation correction from True north. For example, as of March 2010, near San Francisco the magnetic north is about 14.3 degrees east of True north, with the difference decreasing by about 6 minutes of arc per year.[2]

When plotting a course, a pilot in most small planes will plot a trip using true north on a sectional (map), then, convert the true north bearings to magnetic north for in-plane navigation use (which rely on cockpit instruments that read magnetic north).

Radionavigation aids located on the ground, such as VORs, are also checked and updated to keep them aligned with magnetic north to allow pilots to use their magnetic compasses for accurate and reliable in-plane navigation

GPS systems used for air navigation can use magnetic north or true north. In order to make them more compatible with systems that depend on magnetic north, magnetic north is often chosen, at the pilot's preference. The GPS receiver natively reads in true north, but can elegantly calculate magnetic north based on its true position and data tables calculate the current location and direction of the north magnetic pole and (potentially) any local variations, if the GPS is set to use magnetic compass readings.

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Wonder what would happen if we ever experienced a polar shift? Could put the entire planet on it's knees, never mind what it would do to aviation.

With thinking like that I wonder if you've been into something you brought back from Dublin?

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With thinking like that I wonder if you've been into something you brought back from Dublin?

Nope, that bottle is reserved for very special occasions. wink_smile.gif

Just saying that a full blown and rapid polar shift could be pretty bad (if it were to come true).

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I recently watched a full "Nature of Things" episode about this very topic. Here's a link to watch the program online (45 minutes):

When North goes South

Very interesting. The main concern does not seem to be navigation but rather the loss of the radiation shielding that the magnetic field provides.

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