Lat/Lon on FMC

[Peter Larsen 885332]

First are the llat/long. wrong in FMC by default?, when i progam a NAT into it it takes me on wrong course.

 

Example i programmed the FMC for the CTP event:

57/20 me back over ireland and over Iceland , 58/30 brought me over Greenland.

 

Another one:

52/20 brings me back over Ireland.

Fx Carpe:

it first says it is on the border between Shanwick and Gander after p[Mod - Happy Thoughts]ing that then it show correct distance to Carpe and direction.

 

What am i doing wrong?.

[Matthew Horan 901577]

When doing N. Atlantic crossing, you should enter as below:

 

57/20 is..

5720N

 

58/30 is..

 

5830N

 

I have a picture of how to enter FMC coordinates, here it is -

 

[Peter Larsen 885332]

Great Chart .

 

But it has to be put in the format of: N00.00 W000.00, so i would imagine 54/20 should be programmed into the FMC as "N54.00 - W020.00", but that takes on a wrong course, i know that's not supposed to go over Iceland and 54/30 is not supposed to go over greenland.

 

If i program the following into the FMC (omitted some): MALOT +53.00 +020.00 - +53.00 +030.00 - +52.00 +040.00 - +51 +050.00 -DENDU - CYMON should give me a proper route via NATa tracks but instead it brings me over Iceland and Greenland which it should not.

 

Let's use the same route to give another example EINN to CYQX simple route, it gives me the correct distances from fix to fix until DENDU which it says is between 3000 and 4000 NM from +51.00 +50.00 which is obviously wrong since there should only be about 200NM.

[Matthew Horan 901577]

I already told you the format -- and its posted in that nifty chart

 

Practical Example:

 

As seen when viewing your North Atlantic Track

 

'V' FOXXE LOACH 57/50 59/40 59/30 58/20 GOMUP GINGA

 

As entered into your FMC

 

FOXXE LOACH 5750N 5940N 5930N 5820N GOMUP GINGA

 

Note the suffix of "N" for all values

[Peter Larsen 885332]

I already told you the format -- and its posted in that nifty chart

 

Practical Example:

 

As seen when viewing your North Atlantic Track

 

'V' FOXXE LOACH 57/50 59/40 59/30 58/20 GOMUP GINGA

 

As entered into your FMC

 

FOXXE LOACH 5750N 5940N 5930N 5820N GOMUP GINGA

 

Note the suffix of "N" for all values

 

I think i may be a little stupid here , explain in abstract terms please .

 

the format in which you have to program the FMC is as stated earlier "+XX.XX +XXX.XX" which means that you route would looke like "FOXXE LOACH +57.50 +000.00 - +59.40 +000.000 - +59.30 +000.00 - +58.20 +000.00 GOMUP GINGA" right?.

 

<---- puts on the dummy hat .

[George Marinakis]

Which FMC are you using Peter? There are a couple of ways to approach entering latitude/longitude coordinates into an FMC. The format suggested by Matthew is used when you are entering LAT/LON coordinates into the FMC as a form of a waypoint. It is not the same thing as entering a specific LAT/LON point (which would be a conditional waypoint - see the second example below). 5750N is the same type of waypoint as FOXXE, LOACH, GOMUP, etc. If that fix (5750N) isn't in your FMC's waypoint database list, it won't be accepted by the FMC.

 

If you want to enter a conditional waypoint in LAT/LON coordinates for the aircraft to fly to, then the proper format depends on which FMC you are using. Since I am most familiar with Boeing products (such as PMDG and LDS), the following examples are for the Boeing FMC. For example, a conditional waypoint for the coordinate for 57 degrees north, 50 degrees west would be entered into the FMC as follows:

 

N5700.0W05000.0

 

If you wanted to do something like N57° 28.45' W40° 36.23' , you would do it as follows:

 

N5728.5W04036.2

 

I believe that the Airbus MCDU uses a different format but the logic is the same. If you enter the coordinate as a waypoint (like Matthew suggested) and the flight plan is not properly created, it usually means you have not used the correct waypoint or it is not listed in your database. If you find that is the case, you can always revert to entering the waypoint as latitude/longitude point which will always be correct. Just follow the instructions for your particular type of flight computer (FMC or MCDU) for entering conditional waypoints in latitude/longitude format and you can't go wrong.

Edited April 26, 2006 at 02:17 PM by Guest

[Peter Larsen 885332]

I belive that X-Plane only has one FMC.

It should be entered as you suggest "+57.00 +020.00" but it takes me over iceland and greenland.

 

I guess it must be the coordinates in the FMC that is wrong then .

Problem is that i will be having alot of troubles giving position reports and it will delay my trip, i don't suppose you can request direct as in "DCT CARPE", TCAS is Default in X-Plane.

 

There is an Airbus FMC comming up soon can't wait .

[Owen Catherwood 903683]

I'm not familiar with X-Plane's FMC, but depending on how they set up the AIRAC database, it may have the 5750N, 5940N, etc. set up as waypoints at their correct lat/lon positions.

[Thomas Hall 933426]

I usually convert the ddmmss on the charts to ddmm.mm in the FMC keeping in mind if I am flying east or west of Greenwich and north or south of the equator.

 

I'm not familiar with X-Plane's FMC, but depending on how they set up the AIRAC database, it may have the 5750N, 5940N, etc. set up as waypoints at their correct lat/lon positions.

[Peter Larsen 885332]

How to use Long/Lat in the X-Plane FMC:

 

Let's say We get: 53N020W that would be entered into the FMC as: +50.00 -020.00 and it applies both ways.

[Ian Elchitz 810151]

First are the llat/long. wrong in FMC by default?, when i progam a NAT into it it takes me on wrong course.

 

Example i programmed the FMC for the CTP event:

57/20 me back over ireland and over Iceland , 58/30 brought me over Greenland.

 

Another one:

52/20 brings me back over Ireland.

Fx Carpe:

it first says it is on the border between Shanwick and Gander after p[Mod - Happy Thoughts]ing that then it show correct distance to Carpe and direction.

 

What am i doing wrong?.

 

Peter,

 

Here's a pointer for you (if not a shameless plug):

 

1) Go to SimRoutes.com

2) Click on Generate Routes

3) Enter your route in the space provided. For Oceanic waypoints enter them as suggested by Matthew Horan (52/20 is 52N20).

4) Press the Generate Route button

5) When the route comes up - select "X-Plane (8.50) and press "Download Flightplan".

 

This will download a ".fmc" file that you save in your x-plane folder and then may load directly into your FMC.

 

You can also try searching for your routing in the SimRoutes database. Routes for North America are there - routes for Europe are sp[Mod - Happy Thoughts].

 

Finally - the X-Plane FMC reads Lat/Lon waypoints internally as a Degrees with Decimal Minutes/Seconds (without the NESW specifics). Thus 52N20 would be displayed as:

 

52 -20

 

While the coordinates for say Los Angeles International (KLAX) would be displayed as:

 

33.942536 -118.408075 (where the positive for Latitude specifies northern hemisphere while negative longitude specifies western hemishere).

 

Anyhow - try it out, it works and saves you time and effort.

 

Ian.