Does your CG Envelope look like the following picture?
Sample CG Envelope problem
If yes, check the following two things in your Weight & Balance setup:
- Be sure a Moment value is entered in the 'Empty Aircraft' section on the Weight & Balance setup page. Most setup values are Arms (in.), but this particular line requires a Moment (in-lb.) value.
- Check if the Pilot's Operating Handbook (POH) shows an empty moment divided by 100 or 1,000. You may need to multiply the moment value of the POH by 100 or 1000. If you know the Arm for this value, you can multiply the Arm by the Weight to get the Moment (Arm x Weight = Moment).
Also, if using a Fuel Moment table, be sure to enter the values in Moments rather than Arms.
Be sure you are using an Empty Aircraft Moment and not an Arm
See the Weight & Balance in ForeFlight Mobile guide (also available within ForeFlight Mobile under DOCUMENTS > CATALOG > FOREFLIGHT on the iPad) for more details.
NOTE: Any time you see a value as "in-lb", the value is a Moment. If the value is simply stated as "in", then it is an Arm.