Originally Posted by
pattern_is_full
This is not even speculation, just a "scenario" that might fit that reported throttle and control-input reading.
Massive incapacitation of PF (bird through the windscreen, medical, other), body pitches forward onto both column and (hand) throttle levers. Nose-over forces make it impossible for the other pilot and jumpseater to clear the controls until too late (that possible last-second attempt to get the nose up).
EDIT: I see I'm not alone - but it would certainly require a "Black Swan" event.
Pattern, I've been thinking sudden incapacitation for a couple of weeks (early on I postulated a large bird through the forward bulkhead as a possibility if you go back enough pages) - or something acute such as a massive heart attack could pitch the PF forward into the controls (granted, also moving the throttles makes it somewhat less likely - but SOP is to have a hand on the throttles during approach so not impossible). 18 seconds is not much time to overcome the startle factor, recognize and react to something completely unexpected - especially with a 200 lb. pilot laying on the yoke. In short, it wouldn't need to be deliberate, just sudden and unexpected.
AFAIK, control column deflection and control force aren't mandatory FDR parameters per Annex 6.
This was an early 1990s build aircraft - and as digital memory was getting cheaper the number of non-mandatory items on the DFDR really exploded in that time frame. Both a benefit and a curse when you were reviewing incident data - with so much data available it could make it a real challenge to sift the wheat from the chaff...