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fsxenthusiast

Having issus with the FMC

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I'm not sure what I'm doing wrong, but I've been testing the 777 on just a round trip, from say KLAX to KLAX, just doing a circle around the airport to get the hang of it. I'd program the FMC like it shows on tutorial #1, setting my current position in the POS INIT and then in RTE I would put in KLAX to KLAX, set my dep/arr to KLAX Rwy 7L -> klax ILS 7l No sid/stars, just wanting to circle the airport and come in again to test it out.

 

I'd then go to my legs page, and it would have a discontinuity [][][][] and I would click the one below, and move it up one to close the discontinuity. The ND will show the purple line just fine, circling the airport, and returning to the same runway. I turn on the Flight directors on both sides, select VNAV/LNAV set my altitude and speed on the MCP and then set flaps, set RTO on brakes, and I take off...

 

The moment I take off, all the legs will just disappear and the next leg is just Rwy 7L, and the plane has no path to follow so it just goes into a set of left/right turns not following any path, eventually possibly even just taking me back to the runway in the middle of the airport. This has happened every time so far I'm not sure what I'm doing wrong.

 

I also can't even seem to get the step mode to come on as it shows in the tutorial:/ Anyone have any ideas as to what I'm doing wrong to cause the legs to all vanish?

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I'm sure someone who knows the plane much better can comment in a more technical way, or correct me if I'm wrong.

 

From what I understand, the modeled FMC cannot calculate the path from point A to point A directly, as the moment you are at point A, that path is complete. So, what you're seeing - is normal behavior.

 

There are three things you can do that come to mind.

 

1) Program a pattern of custom waypoints based on your runway 7L. I'd say give upwind and downwind legs some 10mi and crosswind and base ones about 3. That should give you plenty of space and time to work through landing prep.

 

2) Use other A/P modes - heading, v/s, etc and fly the pattern.

 

3) Fly it by hand. It's much more fun than letting the computer fly it. 

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Yes, but there were legs in there that would take me around the airport? Here's the settings I had set

 

on the dep/arrival page i had set for departure KLAX 7L and arrival ILS 07L

 

On the legs page, there are 3 rows, 1st leg is FEKIL and the 2nd leg is TURKA, 3rd leg is Runway 7L.

 

The moment I lift off, FEKIL and TURKA both disappear before I even reach them.

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I still think this happens because you reached 7L. All prior waypoints will be deleted. Try setting the arrival after you've taken off.

 

You should really fly patterns manually. You will learn a lot about how the plane reacts and behaves. It will also help you a lot to understand what A/P does and provide much better entertainment :-)

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Nothing looks out of the ordinary here.  The FMC's route feature is really there to make cruise sections easier in the case you're flying to a destination farther away via multiple waypoints.  What you're doing, it would make more sense to depart, do your flying around, and then select your approach when heading back to the airport.

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