The term 'Plane Type' can refer to two different types of aircraft: a JET and a DCIO. A JET is an aircraft powered by JET engines, which are engines that use a combination of air and fuel to create thrust. DCIO stands for 'dual-control instrument-only, ' which is a type of aircraft that is designed to be flown only by a pilot with a valid instrument rating. Both jets and DCIOs are used for commercial and private aviation purposes.