Exactly,
There is no way to convert thrust to horsepower.
It might be some approx tumb rules that apply in some cases, but thats all.
THRUST (F)
Is meassured in Newton.
It is defined by Newtons 2nd law -
mass*acceleration
F = m * a
F = kg * m/s^2 = N = Newton
1N = 0,102 kp = 0,225 lbf
POWER (P)
Is meassured in Watt -
energy
pr second
P = E/t
P = J/s (joules/sec) = W = Watt
1 hk = 0,7355 kW = 75 kpm/h = 632 kcal/h
1 hp = 0,7457 kW
As you can see, these have nothing in common.
One can offcourse meassure some brake power
on a jet engine shaft, but this is sort of pointless
since the shaft isn't pushing the acf forward, the
MASS accelerating through the engine is... .
Cheers,
M