Re: Pulling a Stop to Runway Overruns
Simple question.
Is the nose landing gear oleo FULLY COMPRESSED under braking?
If not then ANY reduction in nosegear download WILL raise the nose, by an amount equal to the reduction in download times the effective spring stiffness of the oleo. I would suggest that there are very few types which completely compress the nose oleos, if for no other reason than to completely compress on an oleo risks mechanical damage and significantly affects nose gear damping behaviour.
If that is a significant distance - and on some types it will be, you may rest assured of that, especially at more aft cgs and lighter weights - then there will be an increase in AoA and corresponding increase in AoA and REDUCTION in load on mains due to increased aerodynamic lift.
Just to be clear: I recognise that OVERTALK and others are suggesting a progressive increase in tail download. The reasons I will CONTINUE to harp on about "full back stick" are:
(1) a procedure which requires modulation of input will ALWAYS carry the risk of someone pulling full back on the "if a little is good, a lot must be better" reasoning
(2) in order to obtain a significant improvement in braking a LOT of tail download is required - to the extent that full back stick will be used at some point
There is already a nominal 67% planning margin between your "landing field length" and "actual landing distance". Unless a technique is going to make a significant impact relative to that 67% margin, it's not going to do much. That means a lot of redistribution of reactions, and that means a lot of tail load.