Return-Path: Sender: "Marvin Kaye" To: lml@lancaironline.net Date: Sat, 02 Apr 2005 00:00:25 -0500 Message-ID: X-Original-Return-Path: <5zq@cox.net> Received: from lakermmtao09.cox.net ([68.230.240.30] verified) by logan.com (CommuniGate Pro SMTP 4.3c3) with ESMTP id 852363 for lml@lancaironline.net; Fri, 01 Apr 2005 23:03:25 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.240.30; envelope-from=5zq@cox.net Received: from OFFICE ([68.110.249.147]) by lakermmtao09.cox.net (InterMail vM.6.01.04.00 201-2131-118-20041027) with SMTP id <20050402040237.ENCB28448.lakermmtao09.cox.net@OFFICE>; Fri, 1 Apr 2005 23:02:37 -0500 X-Original-Message-ID: <028e01c53738$a0c6b340$6401a8c0@OFFICE> From: "Bill&Sue" <5zq@cox.net> X-Original-To: "Lancair Mailing List" X-Original-Cc: References: Subject: Re: ICE X-Original-Date: Fri, 1 Apr 2005 23:01:11 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0289_01C5370E.B25C7240" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 This is a multi-part message in MIME format. ------=_NextPart_000_0289_01C5370E.B25C7240 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable A while back, there was a lot of discussion about > how much space should be left between the control horn and the = horizontal > stab. The consensus was that you had to leave space to avoid ice = building > up there, and jamming the controls. What spacing do you have, and = were you > aware of any control restriction during your incident? It sounds as = though > your situation was about as bad as it gets without disaster, so it = would be > interesting to know if there were any control effects. > =20 > Jerry Hello Jerry, > You did not mention whether there was any evidence of ice around the > elevator control horns. Actually, in reply to Scott's questions yesterday, I did address this = subject. I have included a copy of my reply below. I have very tight = clearance between the elevator counter weights and the h stab, less than = 1/8 inch. I noticed no icing on the counterweights and no control = "freezing". In my situation, if the "solution" to elevator freezing was = to allow sufficient clearance for ice, I would have needed more than 1 = 1/2 inches since this is the amount of ice that accumulated on pretty = much all exposed forward facing surfaces. Setting the h stab angle of = incidence correctly so that the counter weights remain "fared" behind = the h stab and so that the h stab and elevator are not fighting each = other is, I believe, much more critical than allowing space for ice. =20 3.. Could you report on the tail plane icing? I read the story of the = prolonged climb with the ice locking control surfaces on the IV - Ice = buildup on the under surfaces, too? I have been concerned about the = tail because of the sharp leading edges and the potential for building = ice first. The horned pattern ("horns" above and below the LE with a forward facing = concave shape between them) was the same on the h stab as the wing. I = was aware of the possibility of freezing the controls and kept moving = them rapidly every 30 seconds or so. At no time did any of the controls = freeze. My elevator counter weight is "faired" behind the h stab pretty = well and, as far as I could tell accumulated no ice. One feature of the = LNC2 that probably helped is the fact that there is not very much tail = down force required to maintain level flight. This is one of the things = that makes our planes so sensitive in pitch. In an icing situation, it = probably helped prevent a tail plane stall. BTW I have the small tail. = Bill Harrelson 5zq@cox.net N5ZQ 320 950+ hrs N6ZQ IV 1% ------=_NextPart_000_0289_01C5370E.B25C7240 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
  A while back, there was a lot of = discussion=20 about
>  how much space should be left between the control = horn and=20 the horizontal
>  stab.  The consensus was that you had = to leave=20 space to avoid ice building
>  up there, and jamming the=20 controls.  What spacing do you have, and were you
>  = aware of=20 any control restriction during your incident?  It sounds as=20 though
>  your situation was about as bad as it gets without=20 disaster, so it would be
>  interesting to know if there were = any=20 control effects.
> 
>  Jerry
 
 
 
Hello = Jerry,
 
>  You did not mention whether = there was=20 any evidence of ice around the
>  elevator control=20 horns.
Actually, in reply to = Scott's=20 questions yesterday, I did address this subject. I have included a copy = of my=20 reply below. I have very tight clearance between the elevator counter = weights=20 and the h stab, less than 1/8 inch.  I noticed no icing on the=20 counterweights and no control "freezing". In my situation, if the = "solution" to=20 elevator freezing was to allow sufficient clearance for ice, I would = have needed=20 more than 1 1/2 inches since this is the amount of ice that accumulated = on=20 pretty much all exposed forward facing surfaces. Setting the h = stab=20 angle of incidence correctly so that the counter weights remain = "fared"=20 behind the h stab and so that the h stab and elevator are not fighting = each=20 other is, I believe, much more critical than allowing space for=20 ice.
 
 
 
 
 
  1. Could you report on the = tail plane=20 icing?  I read the story = of the=20 prolonged climb with the ice locking control surfaces on the IV =96 = Ice buildup=20 on the under surfaces, too?  = I=20 have been concerned about the tail because of the sharp leading edges = and the=20 potential for building ice first.

The horned=20 pattern ("horns" above and below the LE with a forward facing concave = shape=20 between them) was the same on the h stab as the wing. I was aware = of the=20 possibility of freezing the controls and kept moving them rapidly every = 30=20 seconds or so. At no time did any of the controls freeze. My = elevator=20 counter weight is "faired" behind the h stab pretty well and, = as far=20 as I could tell accumulated no ice. One feature of the LNC2 that = probably helped=20 is the fact that there is not very much tail down force required to = maintain=20 level flight. This is one of the things that makes our planes so = sensitive in=20 pitch. In an icing situation, it probably helped prevent a tail = plane=20 stall. BTW I have the small = tail.   

 

 

Bill=20 Harrelson

5zq@cox.net

N5ZQ =20 320  950+ hrs

N6ZQ   IV   =20 1%

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