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# Tag Info

60

If an aircraft is following a magnetic course changes in magnetic declination as the aircraft moves along its route of flight will affect the true course, and on a long flight such as the hypothetical trip posed here we need to take that into account. Magnetic declination is empirical data, i.e. there are tables of it, and while formulas exist to ...

38

The general rule is: If you read it, it's true. If you hear it, it's magnetic. All charts and textual sources (METAR, TAF, winds aloft, surface analysis charts, etc) use true north as the reference. ATIS/AWOS/ASOS broadcasts, or any information a controller gives you over the radio, is magnetic. Wind direction broadcast over FAA radios is in reference ...

17

Implementing changes to runway numbers is quite complicated and requires a lot of different parties to get involved. There is a ton of related information in FAA Order 8260.19E and it has the details. Simple Version According to an article by the NBAA called "How Changes in Magnetic North Are Impacting Airports": “Adjustments to runways like this and ...

16

Short answer: Yes there is, but it doesn't always work, it involves a LOT of math, and you're probably not gonna like it. Medium Answer: Most flight planning software incorporates a True/Magnetic heading conversion system (ForeFlight for example). Using an electronic flight planning tool like this is probably your best bet if you want an on-the-fly ...

15

The "heading" refers to the direction an aircraft is pointing. For a Magnetic Heading, this is in relation to Magnetic North. For a True Heading, this is in relation to True North. True North is directly over the earth's axis. Magnetic North is somewhere over Canada, moving towards Russia. To get the Magnetic Heading, you just read it off the magnetic ...

14

How do you think "the figure seems to show an extreme variation of up to 90 degrees"? I don't think you're understanding that diagram correctly. There is nothing close to a variation of 90° anywhere that is populated. The angle of the curve has nothing to do with how strong the variation is. All points on a single curve share the same variation. If ...

12

Take a closer look at the map. The contour lines show the places where the magnetic deviation is the same. The green lines specifically show where the deviation is zero, so in Indonesia the deviation will be close to zero. The green line runs roughly East-West, but that's indication that there is a region roughly East-West where the declination is zero. The ...

9

The lines in your plot indicate paths along which the magnetic deviation is constant. If one plots the direction of north as displayed by a magnetic compass, one gets the blue arrows in the following image: I've also marked the regions where the direction of magnetic north deviates less than +/-0.1° from the geographic north in green, and you can clearly ...

7

True North is the North Pole. The maps used for navigating are oriented to the North Pole. A pilot can measure the direction between two points to create a 'track' or 'course' to fly in degrees true. Magnetic North is where the compass points - which is not actually the North Pole. Magnetic North is currently over northern Canada. The angular difference ...

6

Because the present position of the magnetic pole pole is such, that in central and eastern US states the isogonic lines are tilted to the West. But in western parts of the U.S., those lines are tilted to the East...

5

The chart supplement does list the magnetic variation of the VORs. Looking under the "radio aids to navigation" section for a nearby airport, it's listed at the end of the line, right after the elevation. BATTLE GROUND (H) VORTACW 116.6 BTG Chan 113 N45º44.87´ W122º35.49´ 160º 9.6 NM to fld. 253/21E. Another source is the radio fix and holding data ...

4

Since the magnetic variation is +0.27°, the "zero bearing" is equally +0.27° east of true north and therefore the (undeclared) valDeclination must be +0.27° as well. You are assuming that the VOR alignment will always be kept bang-up-to-date with the actual measured magnetic variation. Sadly, this is not the case! There is actually a considerable amount ...

4

The true north pole, aka the celestial north pole, is the point on the Earth's surface intersecting Earth's rotational axis on the northern hemisphere (and thus the axis around which all stars appear to rotate). Prior to the introduction of the Global Positioning System, there were no perfect indicators of true north. Two competing and often conflicting ...

4

In fact, magnetic variation (often called declination) can be as much as 180°. If you walk from the axial south pole towards the magnetic south pole, or from axial north to magnetic north, your compass will be backwards. Of course, the real magnetic field is rather "imperfect", as your diagram shows, so standing exactly between the two south poles might not ...

3

This won't work. What to shield Most of the cosmic radiation has quite low energies and can easily be shielded by the hull of an aircraft, spaceship or spacesuit. This would also be shielded by the atmosphere, but it would also burn/blow it away over time due to the intensity of the radiation. For luck, the magnetic field of the earth shields us from this ...

3

There is no real need to change the runway identifier just because the variation changed. Sometimes this is done but you'll find enough places aroud the world where there is up to a 10 degree offset (maybe even more) between the numbers on the runway and it's magnetic orientation. At some biger airports with more then three parallel runways this is even done ...

3

Magnetic direction and true direction are interchanged with the help of variation. Rule of thumb is: Variation west magnetic best ( more than true) Variation east magnetic least ( less than true) Or MD + VAR EAST = TD MD - VAR WEST = TD

2

True north (geodetic north) is the direction along the earth's surface towards the geographic North Pole. True geodetic north usually differs from magnetic north (the direction a compass points toward the magnetic north pole), and from grid north (the direction northwards along the grid lines of a map projection). Magnetic declination is the angle between ...

2

Yep, that's how it's done! (If you fly the same airplane all the time, one other thing you could do is take a photo of the compass card. That way, you have the deviation already handled and you save a step at the airport.)

1

The chart shows you lines of equal declination $D$. You identify your location on the chart (which you have done and marked with an X in your second image). Then you determine on which line you are. It looks like the point is between the -26° line and the -28° line, so let's call it $D=-27^\circ$. That gives you a magnetic track of:  \varphi_\text{mag} = \...

1

QDM is magnetic bearing to station, QDR is magnetic bearing from station so VAR and DEV are here only to confuse you; the QDR is opposite of QDM so the answer is 099. Notice that QDR and QDM do not depend on aircraft’s heading or flight path, they are only dependent on A/Cs location relative to the station.

1

Surface winds, as reported by the tower are magnetic. Runway headings are magnetic. However, METARs are reported true, according to Aviation Weather Services and ICAO. Therefore one has to perform a heading correction in comparing runway headings to METARs. Wind directions are normally rounded to 10 degrees, as are runway headings. However, sometimes ...

1

I would calculate that leg in two segments. From GIJ to BENJO flying a course of 082 magnetic (50 NM), thence from BENJO to CRL on a magnetic course 087 (79 NM). In addition, the magnetic variation is only applicable to hand plotting an arbitrary course using the map's orientation as a reference; IFR charts list true magnetic courses on their airways for ...

1

Metars are used by more groups than just aviation. In the U.S. it is official weather for the National Weather Service. It is easier to graph winds in relation to true north than have them in shown in magnetic north. The graph wouldn't make much sense. Spoken winds are in magnetic because they are specific to aviation and that is what pilots care about.

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