By what scale is Latitude and longitude calculated on aircrafts?
If we travel by 1 metre on any side how much of longitude and latitude changes?


It depends where you start. One nautical mile is defined as a minute (1/60 of a degree) of longitude at the equator. This is about the same as a minute of latitude at the equator, but because of the shape of the earth, it's not the same as a minute of longitude anywhere else: lines of longitude get closer together as you head north or south, and they all meet at the poles. If the earth were spherical, the lines of latitude would all be the same distance apart, but it's not quite: it's squashed flat, like an orange, so latitude lines get closer together as well, but never meet.

Because it's simple geometry, you could make a formula to tell you the length of a minute of latitude at any latitude, and another to tell you the length of a minute of longitude at any latitude, but we don't do this, and here's why.

Latitude and longitude are a good way to describe where you are, but not how you're travelling. Instead, you plan to fly a certain distance in a certain direction. You can tell the distance by multiplying your speed by the elapsed time, same as any other navigation.

You can measure your position with reference to fixed points. In visual navigation (in sight of land), you can use geographic landmarks: a particular town is ten miles to the north, or you're directly over a lake. You can also use radio navigation aids: fixed radio beacons which tell you where you are in relation to them. These work even in bad weather or if you're too high to see the ground, and even airlines navigate this way. You can plan a route flying from one landmark or beacon to the next, until you reach your destination, without even thinking about latitude and longitude. When you need to report your position, even in an emergency, you do this by reference to these landmarks or beacons.

If you ever do need to know your latitude and longitude, you can do this by referring to your chart. You find the beacon or landmarks that you're at, mark your position on the chart with reference to those, and read off the latitude and longitude. No need for any formulae, and the only thing you have to calibrate is your compass.