ALSE techs, NCOs and flight crews,
Protecting your noggin is vital during any aircraft emergency. Part of that protection is making sure the chinstrap on your HGU-56/P helmet is secure and functioning.
Recently, a crewmember received preventable injuries during a helicopter emergency, all because their helmet came off during the crash. The likely cause was a frayed chinstrap.
The definition of fraying is: to unravel or become shredded or worn at the ends or edges, typically through constant rubbing. Another definition is: separation of whole yarns at the edge of the webbing structure.
Operator and maintainer PMCS say the helmet shouldn’t be used if the chinstrap is frayed. And there’s no percentage of fraying allowed either. Any fraying means the helmet is non-mission capable.
During PMCS, keep an eye out for fuzzing on the chinstrap. Fuzzing is usually caused by continuous contact with hook and loop fasteners and is not considered fraying. If you spot fuzzing, trim it down to the surface using scissors or a razor blade.
Remember: Repeated use of the chinstrap snaps from putting on and taking off the helmet may result in misaligned double D-rings. Misaligned D-rings won’t securely grip the chinstrap.
An unsecured chinstrap decreases helmet stability and can lead to head injury. So always verify that the chin strap is threaded through the two D-rings when wearing the HGU-56/P helmet.