From John's website:

John O. Graybill has been an active aviator for more than fifty years. He holds a commercial pilot certificate (single- and multiengine rating), glider rating, is a certified flight instructor, is an instrument pilot, has been designated by the Federal Aviation Administration as a master pilot, and has flown private airplanes all over the United States, Mexico, and Central America. He holds an MBA with studies in operations research and statistics. Mr. Graybill is the author of The Entrepreneur’s Road to Business Success and Personal Freedom.

John has owned numerous aircraft, both powered and gliders.

John's newest book, Private Airplane Passenger Safety, is now available at Amazon.