X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 19 Jul 2010 08:59:38 -0400 Message-ID: X-Original-Return-Path: Received: from imr-da06.mx.aol.com ([205.188.169.203] verified) by logan.com (CommuniGate Pro SMTP 5.3.8) with ESMTP id 4398101 for lml@lancaironline.net; Mon, 19 Jul 2010 08:03:29 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.169.203; envelope-from=Sky2high@aol.com Received: from imo-ma01.mx.aol.com (imo-ma01.mx.aol.com [64.12.78.136]) by imr-da06.mx.aol.com (8.14.1/8.14.1) with ESMTP id o6JC2o43003866 for ; Mon, 19 Jul 2010 08:02:50 -0400 Received: from Sky2high@aol.com by imo-ma01.mx.aol.com (mail_out_v42.9.) id q.dd2.c24579d (45492) for ; Mon, 19 Jul 2010 08:02:48 -0400 (EDT) Received: from magic-d17.mail.aol.com (magic-d17.mail.aol.com [172.19.155.133]) by cia-mc07.mx.aol.com (v129.4) with ESMTP id MAILCIAMC077-b1b44c443ee8217; Mon, 19 Jul 2010 08:02:48 -0400 From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Mon, 19 Jul 2010 08:02:48 EDT Subject: Re: [LML] 320/360 CG and Pitch Sensitivity X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_c366f.10eb021.397598e8_boundary" X-Mailer: AOL 9.5 sub 155 X-AOL-ORIG-IP: 67.175.87.113 X-AOL-IP: 172.19.155.133 X-Spam-Flag:NO X-AOL-SENDER: Sky2high@aol.com --part1_c366f.10eb021.397598e8_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit 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 crea_ting more drag. I have not found the short mount to be a big maintenance problem. Regards, Bill Hannahan wfhannahan@yahoo.com_ (mailto:wfhannahan@yahoo.com) --part1_c366f.10eb021.397598e8_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
Holy Cow!  Another variant among the many in the 200/300 series= =20 aircraft.
 
Grayhawk
 
In a message dated 7/19/2010 5:15:38 A.M. Central Daylight Time,=20 wfhannahan@yahoo.com writes:

Many have recommended shortening the elevator bell crank. I agr= ee=20 that reducing the mechanical advantage on the elevator improves st= ick=20 feel, but there are downside issues.


Control system pushrod forces increase.


Any play in control system bearings is amplified by the shorter= =20 throws.


Trim spring forces increase.


My recommendation is to change the ratio by raising the attach= point=20 of the forward end of the forward elevator pushrod. I did this by= making=20 longer tabs that bolt to the existing tabs and hook around the sti= ck=20 torque tube. The alternative is to weld on longer tabs.


I did not like the inertial feel induced by the elevator bobwei= ght.=20 Also it rotates in the wrong direction to compensate for abrupt pi= tch=20 changes. I experimented with different bobweight mass and found my= =20 preference to be zero.


I am not a big fan of the long mount. Extending the cowl and pr= op=20 forward essentially cancels out some tail volume, reducing stabili= ty. It=20 also increases surface area, adds weight creating more drag. I hav= e not=20 found the short mount to be a big maintenance problem.


Regards,
Bill Hannahan



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