Lama Bear said:
I haven't been fortunate enough to fly one of the new generation attack helicopters but every helicopter I have flown will exhibit "Jack Stall" if pushed past it's published limits. Which model do you consider immune?
Nick sez:
The servo strength does not have to be infinate to counter the stall forces from the rotor, because the moment the blades generate reaches a practical limit in deep stall. Therefore, there is not a relationship between the designer building ever stronger servos to counter the pilot doing ever more aggressive maneuvers. A properly designed control system always wins against the blade stall forces.
In US Military service, the maneuvers must be tested to extreme limits in a structural demonstration where we squeeze everything out of the helicopter and make sure that controls, structure and systems all support the pilot. Jack stall is not allowed, and any helicopter that demonstrates it must be redesigned (usually by making the servos stronger).
In short, no Boeing, Sikorsky or Bell product of the last two generations has or can experience jack stall.