B737 stab trim setting v V2
In another forum there has been discussion on rotation technique and in particular why is it in the 737 at least, a normal rotation rate results in the aircraft "pausing" as it reaches 10 degrees and the pilot has to pull a bit harder to get the rotation going again toward the initial 15 degree nose up mark.
Opinions vary and the facts are hard to pin down but I always thought the unintentional pause at 10 degrees was a stick force change as the tail went into ground effect. Someone else said it was a combination of centre of gravity through the wheels still on the ground and the centre of pressure moving forward as angle of attack (?) was increased at VR.
Disregarding the above my question is on certification take off tests on the 737 and the applicable stab trim setting. I understood (probably incorrectly) that provided the stab trim setting was correct on load sheet figures, the stab trim calculation is based upon the 737 reaching 35 feet at V2 speed all engines and in trim.
On the other hand, another view was the certification stab trim calculation was based upon the aircraft losing an engine at V1 and continuing the take off roll to VR and being in trim at V2 at 35 feet with one engine inoperative.
Having thankfully never experienced a real engine failure at V1 and thus only simulator experience to fall back on, I can say with some authority that in the 737 various simulators I have "flown" the stab trim setting certainly was way out at V2 one engine inoperative. In fact one needed a prolonged and heavy pull force at VR when an engine was failed at V1 and the take off run continued. The stab trim setting for the all engines case meant rotation forces at VR were normal passing V2 but in my experience were out of whack by at least two units on the engine failure and go case at V1. This was common to all the 737 simulators I have operated.
Judging from the 737 Classic simulators I have operated in several countries, the same comments I made earlier held true. Does this mean that it is correct or incorrect to say that the setting of the stab trim (certification flight tests) from the load sheet ensures the trim is perfect passing V2 at 35 feet all engines? Or are all the simulators lacking fidelity in that area of operations?