H(H) designation question in C-130 General Posted July 17, 2008 \"I\'ve only actually seen it on our manuals, like the 1C-130(H)H-2-11.\" The H(H)designations in pubs started with the AF and the Rescue birds built in the 60s for ARRS. -15 engines, GTC, yokes and Benson tanks, etc. The (H) designation also showed up once when we had our own Dash one printed by the AF. It was an odd thing 1C-130B(H)-1 (not to be confused with the old AF pub that included our HC-130B ). We started using our own CG dash one in 1982. Combined a few checklists, etc. As for the -7 engines on new airframes, that was all money and politics driven. It was found that it was cheaper to by new airframes rather than upgrade the corrosion riddled \"Bs\" (12) \"E\" (1) and HC-130H (3). Also looming over us was the fact we could have gotten stuck with a different airframe and that would not have been a good thing. So the program was devised called PILOC (procurement in leu of conversion). We lots of spare C130 parts and the ones that topped the heap were engines. Rumor had it some Congressman asked why the CG was buying new C130s when the Navy Reserve was sending P-3As to the desert (typical). Over the years many of the components of the -7 engines were upgraded to -15 standards (ie gearboxes) so the final upgrade to -15 engines on the 1700-1709 airframes was much less expensive than other operators were facing.