One of our goals has always been to have the best free model airplane calculator and the best subscriber-only calculator. We’ve always expected to have many more free registered users than paid subscribers. Although there are close to 2,500 registered users, only a handful have chosen to become subscribers. I hate having to do this, but clearly an adjustment was called for.

Effective immediately, most of the interactive charts in the calculator are now only accessible by the paid subscribers. There are no free calculators that come even close to having nice charts like these, so we feel justified (though reluctantly) in making this change.