C-130 #4180 incident on November 8th, 2018
Folks, the incident report is an internal document hence cannot be posted here. (and also because its the long one)
I would, however, post (in my own words) declassified core details and causes of the accident in layman terms.
The maximum torque produced by each engine is around 19600lb
On approach, the torque is leveled down to 3500lb 3500lb 3500lb 3500lb (for all 4 engines)
Upon touch down, the aircraft is idled at 1000lb 1000lb 1000lb 1000lb
Upon slowing down below 115 knots, reverse thrusters are engaged to produce NEGATIVE -3500lb -3500lb -3500lb -3500lb
However, there is a phenomenon called 'Pitch Lock'. The blade angle of the propeller is locked and hence torque remains high.
The engine No.1 of C-130 produces the most torque due to some design characteristics of the aircraft.
The engine No. 1 of the C-130 was pitch locked, leading to the rise in torque at +5500, while the rest of the engines were at -3500. This forced the aircraft to wear off the runway due to the induced force produced by this effect.
Pitch locks happen sometimes, but they are the most difficult to recover from once the aircraft engages reverse thrusters.