I have spent hours trying to set up my FMC for a KJFK to EGLL flight.  I used the max number of passengers, no additional cargo.  PFPX was used for flight planning.  The calculated CG% for takeoff was 27.1%.  The FMC gives me an error that it's invalid.  I have tried everything I can to get my V speeds but regardless of setting departure runway, wind speed and velocity, flap setting according to TOPCAT, but I cannot get V speeds.  

Hi,

have you tried to just click the line select key besides the CG entry? That should automatically enter the FMC calculated CG.

Otherwise, try entering nearby numbers and see if it takes them.

4 hours ago, Fritz1965 said:

 The calculated CG% for takeoff was 27.1%.  The FMC gives me an error that it's invalid.

Hi,

Did you try to enter the value manual on the takeoff ref page 1/2 or did you click on the LSK3 to bring the value on the scratchpad then a second time on the LSK3 to enter it?

Remember that the FMC doesn't accept decimals in the CG line.

Don't forget CI. That has tripped me up a couple times.

I fell into the weight distribution trap that others have been talking about for quite a while.  Instead of trying to set up the PAX and cargo weights manually in the FS setup screen, I simply entered the Zero Fuel Weight from PFPX and allowed it to auto-populate the other data fields.  It's been a long time since "flying" the 777 due to all the fun I've been having with the NGX.  

20 minutes ago, Fritz1965 said:

Instead of trying to set up the PAX and cargo weights manually in the FS setup screen, I simply entered the Zero Fuel Weight from PFPX and allowed it to auto-populate the other data fields.

No sure if I read it correctly, but you should enter the weights into the payload page of the CDU and not into the FS menu. You can enter the ZFW into the RSK2 and let the PMDG distribute it automatically between the pax and the cargo. I always do that instead of entering the pax number and cargo weight.

Romain I interpreted his comments to refer to the FS Actions Payload screen on the CDU.

Not yet mentioned is the simple fact that the IRS need aligned before setting V speeds.  I run into this when I start FMS preflight while the ADIRU is still aligning, this is possible all the way up to the TAKEOFF page.

1 minute ago, downscc said:

 

Romain I interpreted his comments to refer to the FS Actions Payload screen on the CDU.

 

You must be right.
However, I have never had any issue in entering only the ZFW while the OP thinks the issue was there in his case.

Just now, Budbud said:

I have never had any issue in entering only the ZFW while the OP thinks the issue was there in his case.

Agree. That is not his problem.  I only enter ZFW 99% of the time.

That's correct- I wasn't doing it the easy way (simply entering ZFW).  

31 minutes ago, Fritz1965 said:

That's correct- I wasn't doing it the easy way (simply entering ZFW).  

So I consider you have your V-speeds now?

Yes, I figured it out and have completed a successful flight.