PPRuNe Forums - View Single Post - Use of Aileron trim on twin prop/turboprop aircraft...
Old 12th Sep 2012, 19:25
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jcomm
 
Join Date: Aug 2011
Location: Portugal
Age: 59
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Use of Aileron trim on twin prop/turboprop aircraft...

First of all I have to state that the only License I own for RL flying is a glider pilot licence (ICAO ) obtainned in 1980 here in Portugal.

I've flown gliders only, all my life, but I am a simulator fan, now involved with a new toy, after having used ELITE for quite a while.

Well, I never really understood if it is acceptable to find considerable bank from torque effects on a prop aircraft, specially a twin with non counter-rotating props, like a Baron58, a Beech C90, a Kingair, etc...

All have aileron and rudder trim, but I wonder if these are particularly set away from neutral for takeoff, full power climbs to overcome slipstream & / or torque effects from their engines, or if those effects are indeed noticeable, making the pilot input right yoke to counteract or use aileron/rudder trim.

The simulator (PC-based) I am now using exhibits a huge amount of left bank on it's Baron58 and C90 models. I have asked the designers if this is realistic and of course was told IT IS!

I do not have any fellow pilots operating such aircraft. At my local airclub I have flown in the right seat of DR-400 and SOCATA 180GT glider tugs, and all I remember is the need for rudder to counteract slipstream assymetric hitt of the tail, probably helped by a yaw moment due to torque roll (?), but I really can't recall (when I was given the chance to fly those aircraft) any noticeable need to use right stick to counter any torque from the engine/prop...

Comments from Baron, C90, Kingair, whatever... pilots are really welcome. Is bank a factor when climbing at full power on such aircraft? Do you use right yoke or aileron trim to counter it or just rudder because yaw and not bank is what is felt?

Ah! Another noticeable effect is right bank when the throttles are brought back during descent, this time requiring either left yoke or left aileron trim. I could understand this if the trims were used before, of course, or if fixed trim tabs are set to compensate for cruise, but I believe those aircraft (Baron58, C90, Kingair, etc...) do not have fixed trim tabs set on ground only but rather trims, either manual or electric, actuated from the yoke, control column, etc...

Thanks in advance for any help / insight on this subject ...

Last edited by jcomm; 12th Sep 2012 at 20:11.
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