Mailing List lml@lancaironline.net Message #55766
From: <Sky2high@aol.com>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] 320/360 CG and Pitch Sensitivity
Date: Mon, 19 Jul 2010 08:59:38 -0400
To: <lml@lancaironline.net>
Holy Cow!  Another variant among the many in the 200/300 series aircraft.
 
Grayhawk
 
In a message dated 7/19/2010 5:15:38 A.M. Central Daylight Time, wfhannahan@yahoo.com writes:

Many have recommended shortening the elevator bell crank. I agree that reducing the mechanical advantage on the elevator improves stick feel, but there are downside issues.


Control system pushrod forces increase.


Any play in control system bearings is amplified by the shorter throws.


Trim spring forces increase.


My recommendation is to change the ratio by raising the attach point of the forward end of the forward elevator pushrod. I did this by making longer tabs that bolt to the existing tabs and hook around the stick torque tube. The alternative is to weld on longer tabs.


I did not like the inertial feel induced by the elevator bobweight. Also it rotates in the wrong direction to compensate for abrupt pitch changes. I experimented with different bobweight mass and found my preference to be zero.


I am not a big fan of the long mount. Extending the cowl and prop forward essentially cancels out some tail volume, reducing stability. It also increases surface area, adds weight creating more drag. I have not found the short mount to be a big maintenance problem.


Regards,
Bill Hannahan



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