LEM queried:
(1) is it true or not that spoilers kill only a fraction of the residual lift?
(2) Is it true or not that we can change our pitch by yoke input during rollout?
answers:
1. A sufficiently large enough fraction that, on an uncontaminated runway, braking coefficients are more than adequate. However it is the very wet and contaminated runways that we are addressing in this thread.
.
2. We can (and would) by backstick braking aft yoke input - if it wasn't for the nose-down pitch effect of spoilers, reverse and natural C of G distribution plus autobrake. Those four pitchdown elements permit a
proportional (and increasing) aft yoke (i.e. up elevator) pilot input as the braking effect increases - which in turn increases the weight-on-wheels and the nose-down pitch due to braking.... which allows eventually up to max backstick.
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As you may have read earlier in this thread, some airliner's SOP's do recommend it and military schools do teach it (backstick braking). It's an example of the widening conceptual gulf between civil and military as less and less of our pilots are now ex-military. Inevitably as the huge tally of overruns continues, manufacturers will be forced to look into ways and means of reducing the toll. Bigger reversers, larger capacity brakes, larger spoilers? Or maybe just automating backstick braking?