A pull test is where the plane, lines and handle ready to fly are checked for safety by attaching a scale to the handle and pulling the control system up to a weight specified in the AMA rule book for a given displacement engine. A safety thong is attached to the handle and has a loop to go over the hand and around the wrist, this is to keep the model from escaping in case the pilot may trip and fall down or have a heart attack or any other reason he might lose his grip on the handle.