Return-Path: Sender: (Marvin Kaye) To: lml Date: Sun, 05 Jan 2003 11:48:13 -0500 Message-ID: X-Original-Return-Path: Received: from imo-d07.mx.aol.com ([205.188.157.39] verified) by logan.com (CommuniGate Pro SMTP 4.0.3) with ESMTP id 1945476 for lml@lancaironline.net; Sun, 05 Jan 2003 09:58:11 -0500 Received: from Sky2high@aol.com by imo-d07.mx.aol.com (mail_out_v34.13.) id q.77.661027b (3310) for ; Sun, 5 Jan 2003 09:58:07 -0500 (EST) From: Sky2high@aol.com X-Original-Message-ID: <77.661027b.2b49a1fe@aol.com> X-Original-Date: Sun, 5 Jan 2003 09:58:06 EST Subject: Re: [LML] Re: Mac Trim Runaway X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_77.661027b.2b49a1fe_boundary" X-Mailer: AOL 8.0 for Windows US sub 460 --part1_77.661027b.2b49a1fe_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 1/5/2003 2:26:31 AM Central Standard Time, rsmiley@centurytel.net writes: > ANY OTHER COMMENTS ON THIS FROM YOU OTHER GUYS??? > > Bob Smiley > Bob, Re: 320/360 1. I like the Reichel geared wheel spring driven elevator trim. The only way it can experience run away is if I have a muscle spasm. 2. I use a Mac servo driven spring bias system for aileron trim. If the servo runs away, I only have to compensate with a few pounds of pressure for the weak springs regardless of airspeed. I don't need the servo movement range for trim in all conditions as I am seldom very far from the "center" indication. 3. Similar servo driven spring system is used for rudder trim - but much stronger springs. Generally I use max right trim for operations below 120 Kts and max left trim for cruise. In a race I have to apply a little additional left rudder above 195 Kts to keep the ball centered. If the servo runs away, I need some leg pressure to overcome the springs ( I've had to do this on landing when I forgot to retrim from left to right at the lower speed). Comments: 1. I like the spring driven system since it is so easy to override (no direct linkage) and there are no trim tabs and consequent extra balance weight. Plus, the control surfaces don't bang around when the airplane is parked. 2. I am going to reduce the leverage on the servo driven arm (aileron trim) so that I need more servo movement for max trim. An additional benefit is that it will be less sensitive. 3. For those with direct linkage servo to trim tab and in addition to power cutoff switches, consider limiting the distance the servo must move so that no more motion is required than that for max trim at all airspeeds and loads. Also, consider reducing the size of the tab. Of course, with a tab, these adjustments might not be feasible because greater tab deflection may be needed at slower airspeeds. 4. At the least, Bonanzas and the Cirrus aircraft use servo driven sping bias aileron trim "cartridges". Maybe someone will design such systems for all the Legacy's control surfaces. Scott Krueger N92EX --part1_77.661027b.2b49a1fe_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 1/5/2003 2:26:31 AM Central Standard Time, rsmiley@centurytel.net writes:

ANY OTHER COMMENTS ON THIS FROM YOU OTHER GUYS???

Bob Smiley


Bob,

Re: 320/360

1.  I like the Reichel geared wheel spring driven elevator trim.  The only way it can experience run away is if I have a muscle spasm.

2.  I use a Mac servo driven spring bias system for aileron trim.  If the servo runs away, I only have to compensate with a few pounds of pressure for the weak springs regardless of airspeed.  I don't need the servo movement range for trim in all conditions as I am seldom very far from the "center" indication.

3.  Similar servo driven spring system is used for rudder trim - but much stronger springs.  Generally I use max right trim for operations below 120 Kts and max left trim for cruise.  In a race I have to apply a little additional left rudder above 195 Kts to keep the ball centered.  If the servo runs away, I need some leg pressure to overcome the springs ( I've had to do this on landing when I forgot to retrim from left to right at the lower speed).

Comments:

1.  I like the spring driven system since it is so easy to override (no direct linkage) and there are no trim tabs and consequent extra balance weight.  Plus, the control surfaces don't bang around when the airplane is parked.

2.  I am going to reduce the leverage on the servo driven arm (aileron trim) so that I need more servo movement for max trim.  An additional benefit is that it will be less sensitive.

3.  For those with direct linkage servo to trim tab and in addition to power cutoff switches, consider  limiting the distance the servo must move so that no more motion is required than that for max trim at all airspeeds and loads.  Also, consider reducing the size of the tab.  Of course, with a tab, these adjustments might not be feasible because greater tab deflection may be needed at slower airspeeds.

4. At the least, Bonanzas and the Cirrus aircraft use servo driven sping bias aileron trim "cartridges".  Maybe someone will design such systems for all the Legacy's control surfaces.

Scott Krueger
N92EX

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