Weight and Balance calculations

[metzgergva]

With a relatively long cabin and luggage in the rear, it is vital to understand the CoG position and the required trim to match the take off speeds for a save initial climb.
Could someone provide the weight and balance section of the KA350 including station positions and CoG calculation or a load sheet to be used manually?
Thank you.

[Slayer]

This is free:

https://www.afmsolutions.com/free_apps_set_1.html

[wells]

I agree, CG data should be part of the MVAMS or something, even a 2d gauge popup would suffice. But, if you look in the aircraft.cfg file, I've put all the stations in there.

The empty CG ( 9800 lbs ) is at FS 194 ( 11.5% MAC ). The MAC is 69.43 inches, leading edge at FS 186.01
The standard seating arrangment,

Crew FS 129
Row 1 Left FS 175
Row 1 Right FS 167
Row 2 FS 216
Row 3 FS 247
Row 4 FS 294
Lavatory FS 327
Aft Baggage FS 359 ( 550 lbs )
Wing Bags FS 234.4 ( 300 lbs each locker )
Fuel FS 193.77

CG forward limit is 191.4 ( 7.8% MAC ) at 11800 lbs or less, with straight line interpolation to 199.4 ( 19.3% MAC ) at 15000 lbs. Aft limit is 208 ( 31.67% MAC ) at all weights.

[metzgergva]

Thanks for the details. Are you sure that main and tip tanks are longitudinal at the same station?

[wells]

Thanks for the details. Are you sure that main and tip tanks are longitudinal at the same station?

It is an average, since the moment changes between full and empty. I suppose they could be averaged separately. The main tanks are outboard of the engines, with the aux tanks inboard. Here are the numbers derived from the chart, for usable fuel load.

539 gals 205.3
380 gals 199.6

average of aux tanks 202.45, or 0.077 in config file

10 gals 182.1

average of main tanks 190.85, or 1.043 in config file

I can roll this into a future update.

[metzgergva]

That’s what I believed that the aux tanks do not change much the CoG, but the the main tanks do move CoG backward the more they are filled the more they help the elevator trim staying neutral.
Hint: Just look at your summary, I think you mixed them up versus the first station statement a few lines above.

[metzgergva]

BTW, it would be great if MVASM would calculate CoG for the entered load situation and calculate a TO trim setting to be trimmed for V2+10.
Could you also check the weight calculation in the FMS versus the load transferred and loaded to the sim?
Thank you for considering.

[KenG]

BTW, it would be great if MVASM would calculate CoG for the entered load situation and calculate a TO trim setting to be trimmed for V2+10.

Take Off trim is very much a pilot technique. 2.5 which is right about the first green UP is pretty much standard and then depending on aircraft total CG you adjust that forward or aft slightly based on pilot experience. There are NO STAB trim charts in the King Air. Not even for the 1900.

[wells]

That’s what I believed that the aux tanks do not change much the CoG, but the the main tanks do move CoG backward the more they are filled the more they help the elevator trim staying neutral.
Hint: Just look at your summary, I think you mixed them up versus the first station statement a few lines above.

They are not mixed up. The outboard main tanks are ahead of the inboard aux tanks. The main tanks include leading edge tanks and nacelle tanks. The aux tanks are located in the center section of the wing chord.

[metzgergva]

Thank you both for clarifications. Got it now. Wrong assumption on my side. Sorry for that.