The term 'Speedy Plane' can be broken down into two crossword solutions: JET (3 letters) and SST (3 letters). JET is a type of aircraft that is powered by JET engines, which are known for their high speed and efficiency. The SST stands for 'supersonic transport, ' which is a type of aircraft that is capable of flying faster than the speed of sound. Both of these types of aircraft are used for commercial and military purposes, and they are both considered to be very fast planes.