E-2/C-2 left thumb control? For some reason I ended up binge watching E-2s and C-2s doing shots and traps on YT. One thing caught my eye; especially during the approach, the pilot’s left thumb is in constant motion pressing a control on the yolk.
One imagines the radio PTT, but there seems to be no relationship between the clicks and talking during the times where both are visible, and it’s not like they are push-n-holding, it’s click click click!
So then one starts thinking about trim, but what madman designs a plane that requires so many trim adjustments during landing, and then requires a separate push for each adjustment?
Anyone know what’s going on? Here’s an example:

                
            
UPDATE: here's another example:

                
            
Look around 0:55 and again at 1:25 - his thumb is positively dancing. I can see in this video it is a hat, so I guess it is trim.
Never having flown anything larger than a s-twotter, what is going on here? I'm used to adjusting trim maybe one or two times in the circuit, this is nuts.
P.s. why the heck is there a privacy screen on the door?
Most likely the pilot is trimming the airplane to alleviate control pressures after he adjusts his airspeed in the pattern.  Ideally you want to trim out any kind of control pressure that you have to place on the yoke, or rudder pedals, first adjusting your speed as desired using the power levers, then trimming using elevator-rudder-aileron trimming procedure. The “coolie hat” switch on the left grip on the yoke provides both elevator and aileron trim.