I use TOPCAT with the 77F profile.  Everything is spot on except for the speeds, for which I use those given by the FMS.

I use TOPCAT with the 77F profile.  Everything is spot on except for the speeds, for which I use those given by the FMS.

 

The V speeds in a proper takeoff performance calculator will be far more accurate than those given in the FMC. In the real world you would override or enter manually the speeds given in the takeoff performance calculator.

 

Alex

The V speeds in a proper takeoff performance calculator will be far more accurate than those given in the FMC. In the real world you would override or enter manually the speeds given in the takeoff performance calculator.

 

Alex

yeah,but is there any way to completely override them? if the Vspeed insterted is more than 4-5 knots dofferent it doesn't accept,any way for it?

yeah,but is there any way to completely override them? if the Vspeed insterted is more than 4-5 knots dofferent it doesn't accept,any way for it?

 

Yep,

 

If you go onto page two and put some entries in (wind, runway slope) the v speeds will get nearer to what your calculator is saying.

 

TLDR; only do this if the fmc won't allow you enter the figures manually. There is no need to use page 2 if you're using a takeoff performance calculator (apart from setting acceleration altitudes etc.)

 

Alex

I use TOPCAT with the 77F profile.  Everything is spot on except for the speeds, for which I use those given by the FMS.

I pretty much do it the way you do. However, Alex Ridge (aceridgey) is correct, The V speeds in the FMC are for a balanced field.

A balanced field is discussed at https://en.wikipedia.org/wiki/Balanced_field_takeoff

HTH

I bought the TOPER calculator. For £8 and all the variants of the 777 (if PMDG ever do make the -200ER I'd be very happy), it's an absolute steal. The V-speeds felt more 'realistic' compared to TOPCAT & what the FMC usually output by itself.

 

Thanks for all your help!

 

Andreas Theophanatos

I use TOPCAT with the 77F profile.  Everything is spot on except for the speeds, for which I use those given by the FMS.

When you have the time try this data in TOPCAT and see what you come up with.

 

The following data should be entered into TOPCAT Takeoff page:

 

Wind 350/3

Temperature +23

Altimeter 30.15

Do not update weather

Take-off Weight lbs. 690283

Flaps Optimum

Thrust Optimum

A/C On

Anti-Ice Off/Auto

Airport EDDF

Runway 25C

Additional  info for 777F FMC - fuel (all in pounds) 191623, reserve 18943, taxi 1140, extra fuel 10000, CI 85, initial altitude FL 300, cargo 188000 lbs.

 

Compute it and see what TOPCAT recommends for about 1000 foot margin. Take that information and enter it on the Thrust Limits and Takeoff Page. I got no vspeeds available.

For info, the same author of TOPER did also a tool for landing calculation called FS decelerate for PMDG Boeing 777.

Thanks Bud, didn't know about this sw.

You are welcome!

I'm just curious as to why you use the 777F in TOPCAT for your -300ER settings?

 

I'm not a real world pilot and I am only a casual simmer, but from what I can see the -300ER has GE90-115B1 engines and while the 777F has the option for GE90-110B1 or GE90-115B1 engines, both TOPCAT and PMDG appear to have used the 110B1 engines in the -200LR and the 777F.

 

Again, i'm not a real world pilot. Is there something about the 777F config in TOPCAT that would make it usable for the -300ER or is it just your own personal preference?

 

Regards

 

Andrew Hill