X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 05 Mar 2012 21:25:52 -0500 Message-ID: X-Original-Return-Path: Received: from vms173011pub.verizon.net ([206.46.173.11] verified) by logan.com (CommuniGate Pro SMTP 5.4.4) with ESMTP id 5429667 for lml@lancaironline.net; Mon, 05 Mar 2012 17:31:54 -0500 Received-SPF: pass receiver=logan.com; client-ip=206.46.173.11; envelope-from=n5zq@verizon.net Received: from p6520y ([unknown] [173.72.178.191]) by vms173011.mailsrvcs.net (Sun Java(tm) System Messaging Server 7u2-7.02 32bit (built Apr 16 2009)) with ESMTPA id <0M0F00ASNNW5RIM0@vms173011.mailsrvcs.net> for lml@lancaironline.net; Mon, 05 Mar 2012 16:31:18 -0600 (CST) X-Original-Message-id: <44C65F6592254009933199BBD265BFA5@p6520y> From: "Bill Harrelson" X-Original-To: "Lancair Mailing List" References: In-reply-to: Subject: Re: [LML] LNC2 - Harminization between pitch and roll X-Original-Date: Mon, 05 Mar 2012 17:31:14 -0500 MIME-version: 1.0 Content-type: multipart/alternative; boundary="----=_NextPart_000_00F9_01CCFAF5.C3E3CEC0" X-Priority: 3 X-MSMail-priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 15.4.3538.513 X-MIMEOLE: Produced By Microsoft MimeOLE V15.4.3538.513 This is a multi-part message in MIME format. ------=_NextPart_000_00F9_01CCFAF5.C3E3CEC0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Randy, 1. Yes, this is characteristic of the LNC2s. 2. There is a proven, Lancair approved, mod that you can make. 3. Yep, several of us. Good results, a little more pitch stick force = required...not quite so sensitive. 4. I use full aft stick on the initial portion of the takeoff roll on a = soft field. Other than this...no. Even a full stall, soft field landing = doesn=E2=80=99t require full elevator deflection (at least on my 320). Your theory on improving the control harmony is exactly opposite of what = you need to do. For the elevator, you want to increase stick FORCE = required for a given elevator deflection, not stick MOVEMENT required. = The way to do this is to shorten the arm on the elevator that the push = rod is attached to. This reduces the stick=E2=80=99s mechanical = advantage and requires a bit more force. It also reduces the limits of = the stick travel in order to reach the full elevator limits (a good = thing). Concerning the ailerons, if you wanted to reduce the stick force for = aileron movement, you=E2=80=99d need to increase stick travel (increase = mechanical advantage). This is, alas, not a practical option. As you = mentioned, full aileron travel already requires that the stick be = pressed against your thigh. Make the elevator mod and leave the ailerons = alone. I think that you=E2=80=99ll like the control harmony a little = better. As I recall, Lancair issued a bulletin about this mod 12 or 13 years = ago. I don=E2=80=99t have the paper handy but I believe that the attach = point for the push rod was moved 1 inch closer to the elevator. = I=E2=80=99m pretty sure that Scott did this mod too and I know that he = has the paperwork at his fingertips (he=E2=80=99s so damn organized). If Scott or someone else doesn=E2=80=99t post the written mod, = I=E2=80=99ll try to find it for you. Bill Harrelson N5ZQ 320 2,030 hrs N6ZQ IV under construction From: Randy Hartman=20 Sent: Monday, March 05, 2012 4:41 PM To: lml@lancaironline.net=20 Subject: [LML] LNC2 - Harminization between pitch and roll To: All LNC2 drivers and anyone else that wants to weigh in on the = subject, =20 Subject: Stick force harmony (or stick movement vs. control surface = movement) between pitch and roll =20 My Lancair 360 (N360DE), which I have flown now for 450 hours, has an = characteristic that I would like some input on from all you = well-informed and intelligent LML readers and contributors. =20 The characteristic is: Very sensitive pitch axis that is not harmonized = with the roll axis. =20 I have gotten used to the difference and frankly don't plan on changing = anything about it unless someone out there has a good suggestion. I have some questions: 1. Is this typical of the LNC2? 2. What kinds of things should I be concerned about in considering = any changes to the linkage of the system? 3. Has anyone made any changes and what were the results? 4. Does anyone out there have any experience with using full pitch = deflection - in any portion of flight? I imagine it might be needed in = landing, full flaps, lower speeds - but I have not seen it. =20 It seems to me the way to make an increase in aileron sensitivity is to = change the mechanical linkage geometry to effectively make the control = surface move more degrees of rotation per degree of stick movement. = This would (and could) be done but the resultant would be the stick not = getting full deflection (as compared to now) in the cockpit when the = aileron was at full deflection. This might not be a bad thing because = right now the stick has to be jammed up against one or the other of your = thighs in order to get the aileron to full deflection. =20 Ideally I would like to have less sensitivity in pitch, resulting in = more stick deflection for the same pitch results as now - and less total = stick deflection in roll, which should result in more roll sensitivity. =20 For clarification purposes - my horizontal stab and elevator are a = one-off design of Chuck Brenner. Chuck was involved with part of the = construction of this project prior to my involvement with it. =20 Randy Hartman Cell (319) 360-9775 ------=_NextPart_000_00F9_01CCFAF5.C3E3CEC0 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable
Randy,
 
1. Yes, this is characteristic of the LNC2s.
 
2. There is a proven, Lancair approved, mod that you can = make.
 
3. Yep, several of us. Good results, a little more pitch stick = force=20 required...not quite so sensitive.
 
4. I use full aft stick on the initial portion of the takeoff roll = on a=20 soft field. Other than this...no. Even a full stall, soft field landing = doesn=E2=80=99t=20 require full elevator deflection (at least on my 320).
 
Your theory on improving the control harmony is exactly opposite of = what=20 you need to do. For the elevator, you want to increase stick FORCE = required for=20 a given elevator deflection, not stick MOVEMENT required. The way to do = this is=20 to shorten the arm on the elevator that the push rod is attached to. = This=20 reduces the stick=E2=80=99s mechanical advantage and requires a bit more = force. It also=20 reduces the limits of the stick travel in order to reach the full = elevator=20 limits (a good thing).
 
Concerning the ailerons, if you wanted to reduce the stick force = for=20 aileron movement, you=E2=80=99d need to increase stick travel (increase = mechanical=20 advantage). This is, alas, not a practical option. As you mentioned, = full=20 aileron travel already requires that the stick be pressed against your = thigh.=20 Make the elevator mod and leave the ailerons alone. I think that = you=E2=80=99ll like the=20 control harmony a little better.
 
As I recall, Lancair issued a bulletin about this mod 12 or 13 = years ago. I=20 don=E2=80=99t have the paper handy but I believe that the attach point = for the push rod=20 was moved 1 inch closer to the elevator. I=E2=80=99m pretty sure that = Scott did this mod=20 too and I know that he has the paperwork at his fingertips (he=E2=80=99s = so damn=20 organized).
 
If Scott or someone else doesn=E2=80=99t post the written mod, = I=E2=80=99ll try to find it=20 for you.
 
Bill Harrelson
N5ZQ 320 2,030 hrs
N6ZQ  IV under construction
 
 
 
 
 
Sent: Monday, March 05, 2012 4:41 PM
Subject: [LML] LNC2 - Harminization between pitch and=20 roll
 

To: All LNC2 drivers and anyone else that wants to = weigh in=20 on the subject,

 

Subject: Stick force harmony (or stick movement vs. = control=20 surface movement) between pitch and roll

 

My Lancair 360 (N360DE), which I have flown now for = 450=20 hours, has an characteristic that I would like some input on from all = you=20 well-informed and intelligent LML readers and = contributors.

 

The characteristic is: Very sensitive pitch axis = that is not=20 harmonized with the roll axis.

 

I have gotten used to the difference and frankly = don't plan=20 on changing anything about it unless someone out there has a good=20 suggestion.

I have some questions:

1.      =20 Is this typical of the LNC2?

2.      =20 What kinds of things should I be concerned about in = considering=20 any changes to the linkage of the system?

3.      =20 Has anyone made any changes and what were the=20 results?

4.      =20 Does anyone out there have any experience with using full = pitch=20 deflection - in any portion of flight?  I imagine it might be = needed in=20 landing, full flaps, lower speeds - but I have not seen = it.

 

It seems to me the way to make an increase in = aileron=20 sensitivity is to change the mechanical linkage geometry to effectively = make the=20 control surface move more degrees of rotation per degree of stick=20 movement.  This would (and could) be done but the resultant would = be the=20 stick not getting full deflection (as compared to now) in the cockpit = when the=20 aileron was at full deflection.  This might not be a bad thing = because=20 right now the stick has to be jammed up against one or the other of your = thighs=20 in order to get the aileron to full deflection.

 

Ideally I would like to have less sensitivity in = pitch,=20 resulting in more stick deflection for the same pitch results as now - = and less=20 total stick deflection in roll, which should result in more roll=20 sensitivity.

 

For clarification purposes - my horizontal stab and = elevator=20 are a one-off design of Chuck Brenner.  Chuck was involved with = part of the=20 construction of this project prior to my involvement with = it.

 

Randy Hartman

Cell (319)=20 360-9775

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