Gray Beard has a valid point. Once I pulled into a public flying field with a friend and a kid was flying alone. I was explaining to my buddy how the RC thing works when the kid leaned over and asked me to land his plane. After I landed his plane, the kid explained that his trainer hadn't shown up and he took off without him there, hoping he would show up before his tank went dry! The kid was very lucky that I showed up and saved his Eaglet.