All:

 

I've had some FMC issues when trying to change STAR and arrival runways in the FMC.  It seems to be isolated to flights where the flightplan is rather large, with say 6 to 10 pages of waypoints, like the KMEM to OMDB run.  The last time it happened to me I tried to change approach and runway with about two pages of waypoints left.  It's hard to describe but I'll give it a shot:

 

(Procedures and runways are fake since I'm not in front of the sim right now)

 

1. Had the ALPHA1 STAR and ILS27L programmed with appropriate transition fixes.

2. Wanted to change to the BETTA2 STAR and ILS27R so I went to the DEP/APP page, and tried to make the choices.

3. FMC appeared to take the change and the EXEC button lit so I pressed it.

4. LEGS page didn't reflect the change but showed a discontinuity and I eliminated it with the next in line waypoint.

 

this is where it gets wonky...

 

5. Route didn't really change and FMC started to behave unpredictably to changes.  Tried to delete waypoints or replace them with no effect.

6. Tried to erase/delete waypoints from the bottom up until I got to a waypoint before the STAR...not working.

 

So, has anyone else seen this problem?  If so, how did you deal with it?  Is there a procedure in the manual about creating an 'enroute' flightplan when the FMC goes nuts?

 

In the last situation where this happened, I simply went "old skool" and flew using my map (skyvector.com) and the MCP and a visual approach to the field.

 

Any hints here?

Nope, I have not seen this or any FMC problem so far.

 

The only advice I can give is:

Dont just blindly press EXECUTE after having selected a different STAR.

(I know it should not cause any problems because you should get a route discontinuity if things dont match, but I dont like blind executing one bit)

Try this.

Select the new STAR and Approach...but dont execute!

Then go to the legs page to see if things make sence. If not then put things as they should be and finally when all seems in order...press EXECUTE.

Steve-

 

I'll pass your report back and see if we cannot duplicate what you saw.  At this stage of the game, we have made a huge number of changes and whatever caused your issue might not be a factor in the SP1 version- but you never know...

 

You won't hear back from me directly on it- but don't worry- it is in the system...

Not that it makes much of a difference as Robert says its in the system now, but I had a similar issue flying YSSY to CYVR when I went to do a rwy change just after TOD into CYVR.