Bucic Posted February 5, 2012 Posted February 5, 2012 (edited) Rudder needs to trimmable as in real aircraft or you cant trim for forward flight and hover which both require a small amount of rudder trim to stay stable. A side note, trimable yaw controls on other helicopters than Ka-50: Just two days ago I spoke to a Mi-2 and Mi-8 mechanic. He told me that their yaw controls are not trimmable (what's the correct term to use?). I was quite surprised as it's not often for Russians to use different implementations between similar airframes. The eurocopters I (kinda) work with don't have trimmable yaw controls either. At least not the EC 135 and EC 145 / BK 117. Wow, are pilots required to hold the pedals in the correct position all the time by themselves or is there some other kind of system to do it? At least the EC-135 seems to have some kind of autotrim system for the yaw channel according to some EC-135 manual found by quick googling. EC135 is simply not equipped with yaw trim system. I reviewed its control system piece by piece. I'm almost certain 130, 120 and 145 are not equipped with it neither. All of them are most probably equipped with AP and SAS of which both should have some yaw authority, so maybe this way pilot is assisted somehow. Edited February 5, 2012 by Bucic F-5E simpit cockpit dimensions and flight controls Kill the Bloom - shader glow mod Poor audio Doppler effect in DCS [bug] Trees - huge performance hit especially up close
AlphaOneSix Posted February 5, 2012 Posted February 5, 2012 Mi-8 has trim for the pedals. That is, there is an electromagnetic brake and clutch and a feel spring for the pedals, just like there is for the cyclic. The autopilot also has a yaw channel, although there is not really any dampening for the yaw channel. The yaw channel of the Mi-8 autopilot is strictly for maintaining heading with the feet off of the pedals. If you have your feet on the pedals, the yaw heading hold function is temporarily disabled until your feet are off the pedals again. The only Eurocopter helicopter I've worked on is the AS332L1 Super Puma, and it had trim for the pedals as well. Also, newer aircraft (and some older aircraft with add-ons) have autopilots that interface with trim servos that have a full range of authority of the flight controls, and basically allow for hands (and feet) off flying for most of the flight. EDIT: In fact, I have never seen a helicopter without trim for the pedals (where "trim" is defined as "force trim" or "spring feel" with a spring and a mag brake).
Bucic Posted February 5, 2012 Author Posted February 5, 2012 (edited) If you could only confirm that Mi-2 also has yaw trim then I could finally settle for NOT trusting the spoken mechanics anymore because that would not be the first case of their crappy 'expertise' :) As for the EC's (135 and 145) I can guarantee there are no trimmers for rudder pedals. Edited February 5, 2012 by Bucic F-5E simpit cockpit dimensions and flight controls Kill the Bloom - shader glow mod Poor audio Doppler effect in DCS [bug] Trees - huge performance hit especially up close
AlphaOneSix Posted February 5, 2012 Posted February 5, 2012 No clue about Mi-2, sorry. The Mi-8, on the other hand...I know more about its autopilot system than I want to know, thanks to one of our aircraft that seems to be infested with gremlins.
Bucic Posted February 5, 2012 Author Posted February 5, 2012 I recall I got a confirmation from both Mi-2 mechanic and Mi-2 pilot that Mi-2 does not feature yaw trim. I'm not certain of anything anymore though. I can't wait to speak to the 'experts' again :sly: F-5E simpit cockpit dimensions and flight controls Kill the Bloom - shader glow mod Poor audio Doppler effect in DCS [bug] Trees - huge performance hit especially up close
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