Help needed with W&B in Foreflight

cccjbr6 · #1 05-13-2015, 08:42 PM

Has anyone set up their RV in the Foreflight W&B calculator? I am trying to but got stuck. It calls for the user to come up with and enter multiple forward and aft CG limit points. Each such point is supposed to have its own unique weight. How do you pick the points and calculate the weights for those points? The Foreflight instructions say to pull it from a W&B graph. I did not receive a W&B graph with our RV-6A and am working from the original W&B. Thanks in advance for the guidance.

Raymo · #2 05-14-2015, 01:17 PM

The W&B spreadsheet at this link should get you the numbers. I found it somewhere, maybe on this forum, so cannot take credit.

EDIT: Just noticed you have a -6A so the numbers will be different.

Van's, I believe publishes fwd and aft CG limits for each model. From there, you have to use moment measurements from the datum to calculate the ARM and weight changes.

flyboy1963 · #3 05-14-2015, 02:17 PM

for some of us, ForeFlight is a bit of a mystery. The power users could really teach a course on it!!!

It's very cool, constantly updated with some new widget ( but never applies to me, or Canada) but still cool.

...only.....when I entered all my W & B moments, the load envelope was UPSIDE DOWN! so obviously, that wouldn't work on my -9a!

but seriously, even if I fudged all the numbers and made them positive, or negative, or whatever, it wouldn't come out right!

any ideas welcome.

Raymo · #4 05-14-2015, 02:24 PM

I use FF but not the pro version. Aviation W&B is less expensive and works well on the iDevices.

cccjbr6 · #5 05-15-2015, 04:53 AM

Quote:

Originally Posted by Raymo

The W&B spreadsheet at this link should get you the numbers. I found it somewhere, maybe on this forum, so cannot take credit.

EDIT: Just noticed you have a -6A so the numbers will be different.

Van's, I believe publishes fwd and aft CG limits for each model. From there, you have to use moment measurements from the datum to calculate the ARM and weight changes.

This is a great spreadsheet but I have a problem. I plugged all the numbers into the spreadsheet. The spreadsheet itself announces whether I am under or over the gross weight but neither an envelope or dots are appearing on the graph and I cannnot find a button or command to make them appear. Any ideas?

EDIT: It may be that I have to construct the envelope with weights and arms. Can anyone point me to directions on how to do that? I googled it for homebuilts but did not find anything helpful.