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View Full Version : Will flying higher mean flying a longer distance?


z.khalid
2nd Feb 2012, 19:22
Rookie question i'm sorry.
But since the earth is round.
Would the higher you fly mean the longer the distance?

pilotmike
2nd Feb 2012, 21:07
If I have understood your question correctly, then the answer is yes, theoretically.

A path around a circumference is just over 6 times greater than the difference between the respective radii (elementary schoolboy maths, C = 2 x Pi x R).

To give a real example, flying at FL380 the whole way around a great circle route around the Earth takes a path about 6,000 feet (or conveniently about 1NM) more than a similar path flown at FL370. But on shorter flights, this extra distance is proportionately smaller, becoming vanishingly small for typical flights.

The extra distance climbing to a higher level then descending again is more significant, yet all these theoretical extra distances are completely negligible when compared to any non-great circle routes, or variations in routing by ATC.

This is related to the somewhat surprising fact, that to raise a theoretical string which is tied tighly around the Equator by 1 metre clear of the ground all the way round the Earth, would only require 6 extra metres of string to be added.

Given the plethora of rather 'odd' and sometimes bizarre questions you have gained a reputation for asking, is it possible that you are worrying too much about unnecessary trivia? Best to focus on the syllabus that your instructor deems appropriate for you, if indeed you are following a flight training course.