It was probably just the Aero Commander 100 that caused him to quit flying. My family briefly owned one and was a bad combination of cruise prop and laminar flow wing that has very high drag at low speed, not to mention a lot of adverse yaw. I had the prop re-pitched to give a better climb and that helped some, but “not climbing properly” was just a way of life for that dog. Any loss of power would be a very bad thing.