Originally Posted by rudderrudderrat
"During unreliable air speed whilst the crew held the wings level using constant left roll input, but with a mistaken light back pressure, it trimmed the aircraft fully nose up in response - without them realising. That's bad."
We've been making rather little note of the important FDR detail, RHS is not recorded. The plane was being flown from RHS, apparently. So that does conjure the notion that RHS, PF, was seeing something vastly different from what was recorded.
I am not sure probes will ice the same way. If the drain hole on RHS clogged PF would have seen a significant (17%) increase in speed. That could be the reason for the initial pull-up. After that the RHS speed indications may have been too highly varied to be used. If the AoA got very large then sensor_validation's note about pitots being straight ahead sort of devices suggests the real airspeed was unknowable in the RHS of the cockpit.
I am wondering if there is a scenario that experienced pilots can concoct that could explain the PF's actions presuming he was a fully qualified experienced pilot, with or without any valid airspeed indication.