4-11. Fitting Procedure.
4-11 .a Fitting Procedure for the HGU-56/P.
HGU-56/P Helmet Assembly
(1680-ALSE-101-1,-2,-3,-4,-5, or -6)
Talcum powder (U-T-30)
ALSE Specialist/Technician or Personnel with
ASI of H2/Q2 (ALSE Qualified)
General Safety Instructions
Proper fitting is essential to the functioning
of the HGU-56/P. all of its modules, and
the safety of the operator/wearer. Take as
much time as necessary to fit the AIHS
precisely. Use extreme care in taking
measurements and checking fit.
Intercommunications Unit (1680-ALSE-181-1)
M-170 Adapter (1680-ALSE-257-1)
If optical systems (ANVIS or AH-l) are to be used, check helmet fit with
optical systems attached. Ensure that the helmet is fitted to the forehead
If M43 CB mask is to be used with helmet, the helmet must be fit with the
operator/wearer wearing an M43 CB mask. Have operator/wearer don mask
before beginning the custom-fitting procedure. Then rub a small amount of
talcum powder (Item 20, Appendix E) over the surface of the hood to ease
donning of the helmet with the heated lining, helmet, shock (TPL).
In preparation for the fitting procedure, operators/wearers with long hair
should arrange their hair so that it lies flat and is completely covered by the
helmet. Elevated hair styles such as buns or French braids will prevent
proper fitting of the helmet. The hair must be worn the same way thereafter.
1. Prior to having operator/wearer don helmet, verify that:
(a) the lining, helmet, shock (TPL) is
aligned with the front edge of the
lining, helmet, shock (EAL).
(b) the lining, helmet, shock (TPL) is against
the crown of the helmet.
(c) the holes in the front of the lining,
helmet, shock (TPL) align with the
plenum ports as shown in Figure 4-7.
(d) the lining, helmet, shock (TPL) is aligned
with the top edge of the nape strap pad
and sits squarely in the helmet.
(e) the nape strap pad is completely pulled
down so that the keeper tab is taut.
Figure 4-7. Alignment of
Lining, Helmet, Shock (TPL) Holes
4-12 Change 1