Original Item: Only One Available. At the end of the 50’s the APH series helmets introduced a new generation of flight helmets characterized by the external visor covered with a protective shield. Improvement of the communication system, internal liner and oxygen mask retainers was also made and in some versions the dual dark and transparent visors system was installed. These types of helmets were the US Navy and USMC standard jet aircraft headgear during the 60’s and throughout the 70’s. In this period the first development of a flight helmet incorporating the Visual Target Acquisition System (VTAS I) was also made.