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This is from the last paragraph here:

... no aircraft crosses directly over the pole – the closest route is 60 nautical miles (nm) away.

User Michael Shen of York University asked this originally under the article.

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    $\begingroup$ no busy route that needs to go there $\endgroup$
    – ratchet freak
    Dec 31, 2014 at 19:31
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    $\begingroup$ I'd be surprised if anything crossed directly over the pole, just as I'd be surprised if anything crossed directly over some other spot in the Arctic. For commercial air service, I don't think the pole is any different than any other point in the area, and so there's no special reason to specifically cross it. $\endgroup$
    – cpast
    Dec 31, 2014 at 21:39
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    $\begingroup$ though one clarification... true pole or magnetic pole? $\endgroup$
    – ratchet freak
    Dec 31, 2014 at 21:57
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    $\begingroup$ It's a multi-government conspiracy to prevent children from ever seeing the truth that Santa DOES exist.... $\endgroup$
    – CGCampbell
    Jan 1, 2015 at 19:52
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    $\begingroup$ Would it be sufficient to establish that there is no pair of arctic waypoints(?) with the appropriate two longitudes? (x degrees East and 180-x degrees West) $\endgroup$
    – DJohnM
    Jan 6, 2015 at 5:45

3 Answers 3

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This article from AA (titled "Over the Top" by Gerard J. Arpey) says,

By the way, because of the limitations of older navigation systems, none of the polar routes we fly crosses exactly over the North Pole. At the Pole, an airplane’s compass changes from a due-north heading to due south, and that change of course could potentially lead to problems with ­earlier-generation autopilot systems. Fortunately, that is not an issue with the latest generation of long-haul aircraft, such as the Boeing 777s we fly, whose source of navigation is the extremely precise Global Positioning System (GPS). Nonetheless, to make polar flying equally effortless for both the new generation and the previous generations of aircraft, none of the approved civil polar routes comes closer than about 60 nautical miles from the Pole.

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    $\begingroup$ Good answer; thanks. As a point of clarification, though, wouldn't the reasoning here apply more to the magnetic North Pole rather the actual North Pole? The magnetic North Pole has, at least historically, not really been very close to the actual North Pole. Interestingly, it has actually moved much closer to the actual North Pole over the last few decades. $\endgroup$
    – reirab
    Jan 2, 2015 at 7:02
  • $\begingroup$ @reirab I don't know. If you want my uninformed guess, it's that the autopilot steers in some particular direction (e.g. "north"). That direction can change with time, but it wan't programmed to (or the programming wasn't certified to) cope with an instantaneous change in direction. $\endgroup$
    – ChrisW
    Jan 6, 2015 at 16:26
  • $\begingroup$ This answer assumes that inertial system conception prevented flying over the poles. But there are other ways for navigating, and the gimbal lock can be avoided if necessary. If no standard routes cross the North pole, maybe this is just because there is no need to. I'd would be curious to see some reference of an expressed need to cross the North pole. $\endgroup$
    – mins
    May 27, 2015 at 17:48
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    $\begingroup$ Is this question asking about the geographic pole or the magnetic pole? The magnetic pole is hundreds of miles away (in northern Canada) $\endgroup$
    – Edward Falk
    May 28, 2015 at 18:29
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    $\begingroup$ @EdwardFalk The map in the article referenced by the OP has a circle drawn over the geographic pole. $\endgroup$
    – ChrisW
    Jun 19, 2016 at 7:29
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I'd like to augment Chris's answer by noting that the mechanical issue in question is called "gimbal lock". It occurs when a three-axis-of-freedom system, such as a gyroscope or compass suspended in two gimbal rings, gets two rings aligned in the same plane. The aligned rings are now "locked" and cannot detect motion in the plane of the rings.

You can imagine the problem by picturing a telescope (or a gun) on an azimuth-and-elevation mount, trying to track an aircraft flying directly overhead. As the plane approaches, the telescope elevates all the way to 90 degrees, but then to follow the plane, it would have to instantaneously spin around 180 degrees in azimuth. A human can easily solve the problem by turning the telesocpe as fast as possible and reacquiring the target on the far side, but an electronic system would have lost the target by the time it finished rotating. Depending on its complexity, it might not even be able to decide which direction to turn in the first place. The same is true of early gyrocompasses flying directly over the pole.

Compasses that suffer from this problem are usually designed to shut down when approaching gimbal lock to avoid damage to the mechanisms. The compass would then have to be reset and manually re-aimed to align with the Earth's rotational axis, which would probably have to wait until the aircraft landed. To avoid the possibility entirely, aircraft are advised to give the pole a wide berth, even though modern gyrocompasses do not suffer from this problem.

That's not to say no aircraft has ever flown over the poles. Admiral Richard Byrd famously made multiple flights over both the North and South poles, and there's no reason a gyrocompass couldn't be designed with polar travel in mind. (It would risk gimbal lock somewhere else on the planet instead.)

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    $\begingroup$ Wouldn't that problem be trivially solvable by simply allowing the telescope/compass/AAA to rotate through 360 degrees of elevation, rather than just 90? $\endgroup$
    – Vikki
    Feb 13, 2019 at 5:04
  • $\begingroup$ Not if you intend to measure directions using azimuth and elevation. Suppose the target is flying from north to south; as it passes zenith and and its elevation begins falling in the South, you continue to track it, measuring azimuth 0 (North) at an increasing elevation of 91, 92, 93 degrees. This is nonsensical, and your readings will continue to be nonsense until another target happens to fly through zenith. As before, the only way to right the system is to stop tracking the target, flip the telescope back to elevations below 90, turn it around, and reaquire. $\endgroup$
    – Martin
    Feb 17, 2019 at 16:51
  • $\begingroup$ @Martin: Why could the system not simply report azimuth 12 elevation 93 as though it were azimuth 168 elevation 87? I think a bigger problem would be if an object flew directly overhead from one direction and then left via perpendicular direction, since one would have to adjust azimuth by either +90 or -90 degrees, but one wouldn't know which. $\endgroup$
    – supercat
    Aug 27, 2021 at 16:12
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Until recently, regulators have insisted that twin-engine jets must always be within three hours of a suitable place to land. This is because the failure of one engine on such a plane is potentially far more serious than for one with three or four.

However, commercial flights do fly over the North Pole. For example:

It is possible to fly over South Pole as well. In 1977, PanAm 747Sp flew over South Pole while flying from Sydney to Recife. However, South Pole does not lie on the great circle route for too many points.

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