Beats me...
Ergonomics and human factors are not my area of alleged expertise. At this incremental, marginal improvement level there are nuances best left to the design experts. Often a perceived improvement in something that is already almost right results in unintended consequences rearing their ugly heads.
The rudder trim knob is already on its second iteration...I don't think that there are too many variations on cylindrical knobs that would fit. The door release mechanism doesn't need to be a rotary knob, but it does need to be something that cannot be triggered reflexively. The door release switch gets used three times every flight at least...maybe it could be something really unique in a really unique location.
The 737 cockpit is, in the words of an Australian Airlines predescessor, an "ergonomic slum". The grandfathering of a mid-1960's design (which has some commonalities with 1930's aircraft that I have flown) poses a seperate ethical conundrum, but the least they could have done is embrace the present, if not the future, last time around. (I am aware of the contsraints in the scope of improvements in each generation, too. Having flown every variant from the -100 to the -800 I think that the range is too broad for one type certificate.)
As an aside: i am familiar with an early DC-8 accident in which spoilers were inadvertently selected close to the ground with landing flap. The resultant high sink rate ended with a high G impact, a go-around with a disintegrating aeroplane which then caught fire and went in like a lawn dart, killing everyone.
The post-hoc fix was a placard which basically said "do not select speed brakes with landing flaps". The pundits of the day observed that the placard could just as easily have read "do not crash this aeroplane".
Interlocks and guarded switches and the manifold other measures have all been incorporated to protect us and our charges from the tired, distracted, sub-optimum versions of ourselves. I do not think that this is a good time to stop that particular pursuit.
Last edited by Australopithecus; 13th Oct 2014 at 20:42.