It's a bad one Chris.
Thank you guys for the input.
too bad,,,RAD helmets really tough to find...
Well, I just had to jump in on this. As a long time helmet collector I don't think this can be declared a fake based on the pictures. It would need a closer exam. RAD helmets are scarce and therefore not as well documented as military ones. The decal is believed to have a few variations and this one appears to fall within the known specs. Read this from Brian Bell of helmets.com:
RAD. The total number of helmets that received this insignia is unknown. When applied, the decal was placed on the right or left side of helmets issued with no insignia. In some cases helmets were given two RAD decals, one on each side. Helmets issued from Army or Luftwaffe supply centers had the RAD decal applied to the right side of the helmet. In some cases, Army helmets have been observed where the RAD decal has been applied directly over the Army insignia. At least two different variations of the RAD decal are known to exist. Others might also exist, although the number is likely to be few.