Blackhawk60,
The most common, and logical, cause of your oil burning is bad valve seals. If you suspect bad piston rings, do a compression and leakdown test.
Your loss of power could be from fouled plugs from the oil being burned.
You do not even have to pull the heads to change the valve seals. So, unless you want to pull the engine and do a rebuild just for the **** of it, do some diagnostics first.
FWIW, the P-47 "Razerback", (as apposed to the "bubble-top") in your icon does not look anythig like a Blackhawk H(eavy)H(elicopter)60.
There aint nothing like the distinctive "wop wop wop" of the UH-1s (Huey) rotors, especially when your waiting for an extraction, and the natives aint friendly. rangerj