interesting note about this helmet shell is the "dimple" that is left forward of the original rearward hole for a comm cord/jack.
I plugged the original hole and set with polyester resin and type E cloth.
The same "multi config." concept that appears on other early shell like the HGU where guide marks (dimples) are
factory pre molded into the shell (ie: HGU-22 shell sub-assembly) for easy build requirements.
The left forward hole may be for oxygen mask cord to helmet speaker jack much like the HGU 2 / 2a/p design.
However, no dimple marks for goggle snaps or the 3 point visor so a lot of question as to the factual similarity
between the 9 and the 16.
Would be nice to find some actual "Technical Order" text on the HGU-9 and other pilot used variants of this shell
regarding actual helmet buildup requirements.
Below is a photo of the dimple that I plan to use (drill out) when I get a Comm harness to install.
Missing from the equation is the slightly oversized black oxide finished metal connector holder that
is seen on most of the "authentic" HGU-9 helmets.
Edited by AMT369D, 06 November 2019 - 08:54 AM.