I went through the knowledge test prep program three times. The first time was before I started flight training, second was during the start of my flight training and then the last time was a week before I took the test (and after 40 hours of flight time). I felt it helped me prepare for the knowledge test. I didn't take any other type of ground school. I got an 88%. I would have done better, but I had injured my back a few days before the test and I was in discomfort during the test and just wanted to finish. Otherwise, I feel I would have easily gotten in the mid-90's.
Thomas L.
01/27/2015
Private Pilot Online Ground School & Test Prep