great circle or rhumb line ?????

[air_cowboy]

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!!!!

[Checkboard]

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.

[Graybeard]

I heard that when Honeywell first flew their EFIS on the MD-80, it was configured for rhumb line map. Guess they thought the world was flat..

GB

[bfisk]

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 :)

[welliewanger]

^^ what bfisk said! ^^

[Piltdown Man]

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.

PM