great circle or rhumb line ?????
Thread Starter
Joined: Feb 2006
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From: BBB
great circle or rhumb line ?????
hi all....
if flying an airway... between 2 vor s ... it is a constant direction track.
but are we flying a rhumb line track or great circle track??
but using jepps which use lamberts conical conformal a straight line is a great circle...
hope have been clear with my question!!!!
if flying an airway... between 2 vor s ... it is a constant direction track.
but are we flying a rhumb line track or great circle track??
but using jepps which use lamberts conical conformal a straight line is a great circle...
hope have been clear with my question!!!!
Joined: Aug 1998
Aviation Qualifications: ATPL
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From: Ex-pat Aussie in the UK
VHF signals travel in straight lines - it's a great circle track. Find an airway long enough, and you'll see the directions are labelled slightly differently at each end.
Joined: Jun 2006
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From: Europe
Hello.
A VOR airway is a great circle track, because of the fact that the radials are straight.
From knowing how a VOR works, the VOR ground station (transmitter) can be aligned/adjusted so that the 360 radial (for instance) is aimed in any direction, however it is common to aim it at magnetic north. Thus, the nomenclature of a radial normally coincides with their magnetic direction at the VOR site, at the time the VOR was built/last adjusted.
As you find yourself on a radial, the "local magnetic direction" of that radial will change with a change in lat/long and magnetic variation. However, the radial, itself, is per definition straight, although various propagation errors may cause it to meander, but that is another story
A VOR airway is a great circle track, because of the fact that the radials are straight.
From knowing how a VOR works, the VOR ground station (transmitter) can be aligned/adjusted so that the 360 radial (for instance) is aimed in any direction, however it is common to aim it at magnetic north. Thus, the nomenclature of a radial normally coincides with their magnetic direction at the VOR site, at the time the VOR was built/last adjusted.
As you find yourself on a radial, the "local magnetic direction" of that radial will change with a change in lat/long and magnetic variation. However, the radial, itself, is per definition straight, although various propagation errors may cause it to meander, but that is another story
Joined: Jun 2002
Posts: 3
Likes: 5
From: Wor Yerm
Airways, VOR's? Ooooh errr missus. Even on the little ones it's type the name in the box and try and remember to press NAV. That will give you a great circle track, the same as what you would have got if you had tracked a VOR radial. VHF radio waves prefer to travel in straight lines = Great circles.
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