"The Flying Keys", brothers Al and Fred, are featured in this 1930's photo collection (14). Photos range in size from 5 1/2" x 5" to 8" x 11". Conditions range from VG-NRMT. The brothers were endurance flyers who set records in the 1930's. As they were spending many hours in the air, in-air refueling was essential but not safe at the time. Working with local inventor A. D. Hunter, the brothers contributed to the invention and application of an in-air spill free refueling system which, with some modifications, is still in use today.