What am I seeing on this HC-130B??

[jennings]

Photos of early Coast Guard HC-130Bs that show the upper surfaces are rare as hen’s teeth. I found this one, and I noticed the dark colored area between the spars inboard of the inboard engines. The photo has be taken sometime between about 1964 and 1967, given the color scheme it carries. Clearly there’s been something done to the wing that required a repaint, since the “U” in “USCG” is missing entirely, and it’s a markedly different color than the light grey walkway area.

Anyone know if this was a structural upgrade of some kind?

Thanks!

[mekong68]

Pretty sure it's nothing special, just part of the the paint scheme. USAF LC-130Hs and WC-130Js do something similar...gloss paint job but it's flat paint inside the walkway to increase grip for walking as gloss paint is pretty slippery even when dry.

[c130kcf]

That's where the aux fuel tanks were. Maybe some fuel cell work was done