A question for all of the pilots, engineers, and people who are a lot
smarter than me. Is there a simple rule of thumb for comparing the amount
of thrust or lift you can get from an engine which drives a set of propeller
or rotor blades to the amount of thrust you can get from the exhaust of a
non-turbo prop engine? For example, a T56-15 from a C-130 has 4,910 SHP and
a J85-21 from an F-5E has 5,000 lbs of thrust (These numbers are from a
twenty year old book of mine. For the sake of this discussion, lets just
assume they are correct). How much actual thrust can you get from the T56
on the C-130? I realize that there must be a lot of variables involved with
the propellers or rotors due to different airfoil shapes and the "lift" that
they provide and the pitch the blades are set at. But I was wondering if
there was a "general rule" that people went by. Keep in mind that math was
one of the main reasons that I dropped out of college and I just spend the
last twenty years as an Aviation Ordnanceman (Population Control) so any
large mathematical equations would go right over my head.
I apologize in advance for posting a question with little chance of
degrading into a political rant.

Evan Williams