Correction noted and sort of accepted. However, to a person following a compass direction (despite the curvature of the Earth) it would seem like flying in a straight line, just as someone going East or North would describe their travel as being in a straight line, despite their actual travel in an Earth following arc.
Not me. You just restated the unquoted part of my rhetorical question.
Going due north, you’re following a geodesic, which is the closest thing you can have to a “straight line” on the surface of a sphere. Likewise straight east, if and only if you’re on the Equator. But in any other case, a constant compass heading will not be a geodesic. This is most obvious near the poles, where a constant-heading curve will spiral around the pole an infinite number of times before reaching it.
A Mercator map was indeed a useful tool in navigation, but it wasn’t the only map used in navigation. If you wanted to plot a minimum-distance course, you’d first plot it on a polar-projection map (which might or might not be centered on one of the Earth’s rotational poles), which has the useful property that straight lines map onto geodesics. Then you’d pick a number of waypoints on that straight line, and find those waypoints on your Mercator map. Then you’d get the compass headings between those waypoints (which would all be different) from the Mercator map.
(of course, real navigation was usually much more complex, because you’d have to consider things like currents and prevailing winds, shallows and other hazards, territorial boundaries, and so on)
Navigating across a continental landmass may be challenging, but I’m fairly confident that, at 3000 feet in VFR, I could fly without charts from Dublin in a more-or-less direct line to several major cities in north-west Europe, or from London to several major cities in the Baltic region, over a distance of maybe 1500 km.
Not so (unless I have misunderstood you). In order to follow a compass direction, other than along the Equator, you will need to make constant corrections. For example, if you want to fly directly east or west along a line of latitude in the northern hemisphere, you will need to keep turning left. If you don’t make these corrections you will find yourself deflected to the right by an imaginary force named Coriolis that wants you to fly a great circle route.
If you want to fly directly east along a line of latitude in the Northern Hemisphere, you’ll need to keep turning left. If you want to fly directly west along a line of latitude, you’ll need to keep turning right. The Coriolis force, even if you’re going fast enough for it to be relevant, doesn’t “want you to fly a great circle route”: A lack of forces is what “wants” that.
A friend of mine in 6th grade (1962) wondered why Supey had to fly in that prone arms extended position- obviously the way he flew had little to do with aerodynamics. After he reached his desired speed, direction, and altitude, why couldn’t he just get into a comfortable position (as if reclining in a La-Z-Boy, for example) and relax? Or roll onto his back, fold his arms and take a nap?
Thanks for the correction. On reflection I was confusing 2 completely different effects, one caused by the earth’s rotation and the other caused by its curvature.
I remember when my hubby was taking his (VFR) flying lessons, and part of the difficulty was knowing where you were. This area is very flat, with corn fields and little forests everywhere, and a few distant rocky hills peeking out, and the roads are all pretty straight. From the air, it all looks alike. You have a map and a compass, you look out the window, and you try to determine which little village is which and thus where you are on the map. (GPS units were available but, for legal/academic purposes, forbidden.) During his navigation exam, he admitted to the instructor that he didn’t know where he was, and he had to re-take the exam a few weeks later.
I have about 30 hours of flight time, which is far from enough to get a license, but sufficient to be able to say that I’ve flown a plane.
Recognizing airports was definitely not easy, and took getting used to. For one, in flight you are moving a lot faster than it seems. Additionally, all buildings and all roadways appear interchangeable in the beginning.
The first few times the OP took off with their newfound flight powers, there’s a fairly good chance that they’d get lost.
Just for the record, when I posted earlier: “Fly high enough to take readings from the stars. How hard could it be?”, I was joking. It would be very hard.
There was an instance a few years ago of a pilot landing a small jet at the wrong regional airport in Missouri. There was a mismatch in communication between the aircraft and the tower and he was landing by sight rather than instruments. Turned out he landed in the wrong place and had no idea. It was an issue as that airport did not have a long enough runway to allow the plane to get airborne again and the passengera were stuck.
I searched for the link for this story and apparently it wasn’t a small jet…it was a Southwest 737. Also this has happened more often than one would think! Not a lot but more than once. I wouldn’t have expected it to happen at all with a commercial jet.
Posting this on my phone so hard to copy links but it was the Branson MO airport in 2014.