FMC location initilization question

[Guest]

How come when I first initialize the FMC - when telling the FMC where my current position is, I notice that the "last position" is always different (only very slightly) from the position called "Ref airport?"If I type in my reference airport, I come up with a slightly different lat & long number. Which one should I use - erf airport, or last pos?thanksChris Catalano

[Jet Tech 31]

Chris,I believe the FMC Last Position is actually its present position on the Airport. The Reference Airport position is usually based on a point somewhere near the center of the Field. On the real 757 you would enter a company gate number into the "Gate" field to pinpoint the position even more.RegardsPaul:-cool

[Guest]

this is really easy to fix....when you get the pos init page, on the right side of the fmc-cdu you will see the in little font GPS POS and then right below that will be a long lat. if you click on the button next to it (believe that it is the 4R button)and then click on the empty line below the text SET INERTIAL POS (5R button)...it will place the GPS position into the inertial pos. hope that that makes sense;) anthony

[Guest]

Oh it makes sense alright. That's pretty much what I have been doing. I just was not sure which was the "real" position (the "ref ariport" or the "last position".Thanks allChris