The term 'PLANE'S FRONT' can be solved by the four-letter word 'AERO'. This word is derived from the Greek word 'aer', which means air or atmosphere. AERO is commonly used to refer to the science of aerodynamics, which is the study of how air interacts with objects in motion. In the context of planes, AERO refers to the FRONT of the PLANE, which is the part that faces forward and is responsible for providing lift and thrust.