Mysterious Rings?

[phoenixphire 50]

I was wondering if someone might be able to help me understand something. Below is a picture of a 747 flight deck. In the FO's centre display in the red circle is a green ring. Would someone please give me some information on what this is and how I can display it on the 747. I searched the manual and wasn't able to find any info. Maybe I am missing it. Thanks in advance.http://forums.avsim.net/user_files/141113.txthttp://forums.avsim.net/user_files/141117.jpg

[Guest B1900 Mech]

Go to the Fix page on the CDU and enter a fix.:-)

[phoenixphire 50]

Got it. Thanks for yor quick reply. I seem to learn something new about this amazing airplane everyday.

[crvm 0]

As example enter "LAX" into the FIX page, under that type and bearing/DISTANCE for the range circle on the ND. Now, say on final you can have a distance marker at a defined point of visual reference ;-) this works great on restrictive departures too................Randy J. Smith................A PROUD MEMBER OF THE PMDG BETA TEAM[h4]Evolution is a process that results in heritable changes in a population spread over many generations[/h]

[NJ_Flyer 3]

isnt it also for alternate airports? If you within the ring, you divert to that one?

[crvm 0]

Nope................Randy J. Smith................A PROUD MEMBER OF THE PMDG BETA TEAM[h4]Evolution is a process that results in heritable changes in a population spread over many generations[/h4]

[Guest JTH]

So "fixes" are a fixed point of reference that you can display on the ND? And you can pick any airport/VOR etc to act as a fix?

[crvm 0]

Yep =P...............Randy J. Smith................A PROUD MEMBER OF THE PMDG BETA TEAM[h4]Evolution is a process that results in heritable changes in a population spread over many generations[/h4]

[Guest 3202b]

"isnt it also for alternate airports? If you within the ring, you divert to that one?"Yes it can be used for this too if you wish, as a guide. For example if you input fixes of two divert airports while crossing the atlantic and set the fix distance the same for each fix so that they touch you can instantly see what airport you are closest to, it also provides better position awareness. Just remember that distance is not the only factor in deciding to divert to a specific airport,

[VHOJT 172]

As far as I know, what some (all?) pilots do for enroute alternates is: say they have two enroute alternate airports along a route. In their flight plan, they will generally be given what is called an ETP (equal time point), this taking into account winds and the likes. This is by way of the distance from a waypoint on your flight plan. You enter this waypoint and the distance in to the fix page, and once you hit the green line, you are at equal time between both alternates.CheersRudy

[crvm 0]

His question was if this is also displayed for alternate "within the ring" to divert to but since the pilot must enter the distance and fix the strict answer is no. It's true you can use it for that but it does not automatically display.................Randy J. Smith................A PROUD MEMBER OF THE PMDG BETA TEAM[h4]Evolution is a process that results in heritable changes in a population spread over many generations[/h4]