In the mid '80s, the H-5 started to be withdrawn from service. After a phase of common equipment with the aircraft ones (Gueneau 316), helicopter crews were equipped with SPH-4s. Stored H-5 started then to be modified with SPH-4 comm harnesses and distributed to helo loadmasters or (if required) to passengers.

More on H-5 HERE

Is interesting to note that during the H-5 phase out era, kids who sent a letter to the Air force asking for a pilot helmet received free of charge a H-5 in his Sportex box... those helmets are sometimes  surfacing from cellars and attics ( frequently sporting unusual liveries or strange modifications) making the happiness of the collectors.