X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 25 Feb 2009 14:43:49 -0500 Message-ID: X-Original-Return-Path: Received: from imo-m19.mx.aol.com ([64.12.137.11] verified) by logan.com (CommuniGate Pro SMTP 5.2.12) with ESMTP id 3515255 for lml@lancaironline.net; Wed, 25 Feb 2009 09:48:17 -0500 Received: from Sky2high@aol.com by imo-m19.mx.aol.com (mail_out_v39.1.) id q.cf2.4f102999 (30739) for ; Wed, 25 Feb 2009 09:48:05 -0500 (EST) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Wed, 25 Feb 2009 09:48:05 EST Subject: Re: [LML] Legacy Gear Retraction Problem X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1235573285" X-Mailer: AOL 9.1 sub 5003 X-Spam-Flag:NO -------------------------------1235573285 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Erik, Remember that the sequence valve is really a check valve that does not allow "up" pressurized fluid to reach the door retraction cylinder until it is defeated by the plunger being depressed. If the sequence valve internal seals (o-rings) or extension spring are less than perfect, perhaps a certain pressure allows some fluid by the check valve, but then the spring is able to re-seat it. Maybe a sequence valve overhaul is in order. Scott Krueger AKA Grayhawk Lancair N92EX IO320 SB 89/96 Aurora, IL (KARR) In a message dated 2/25/2009 7:12:20 A.M. Central Standard Time, asw20747@aol.com writes: We have come up with an interesting problem while doing a recent annual. Was wondering if anyone might have some ideas? Background: We have a well built and well maintained Legacy that has been flying for about 2 years with just under 300 hrs on it. We are doing the (second) annual inspection and on the gear swing found that the nose gear retracts first, then the left main followed by the right main. When the right main went up it did so it with a chatter or shudder, most noticeable, at first, with the inner gear door. In other words, it went up but not smoothly like the other gear or as it has ALWAYS done in the past. In an attempt to trouble shoot the problem we disconnected the inner gear door and checked for ease of movement, binding etc.. All was perfectly smooth with no binding or resistance of any kind. We then retracted the gear without the inner door connected. We still notice a consistent chatter in the right main AND in the inner gear door actuator cylinder, moving without the inner gear door attached. We then took the sequencing valve out of the picture by using a piece of doweling pushed up on the sequencing valve as the main gear retracted (inner door was still disconnected) and now noticed a smooth operation of the gear and the inner door actuator. We have checked that the sequencing valve makes good solid contact with the gear. We checked the up side hydro pressure and it was 1100 psi. We ran this problem by Lancair technical (Ross) and he suggested we bump up the hydro pressure to not more than 1,500 psi up to see if that made any difference. We boosted it temporarily up to 1,425 psi nd there were NO changes. Does any one have an idea of what may be going on? We have considered air in the system but with no leaks and the system operating for quite some time with no problems and many cycles, would air in the system still be a possibility? How about the sequencing valve, seems pretty simple, they either work or they don't, could that be an issue? Since we have been involved in this problem the issue has been consistent, never intermittent, and never involved the other gear. At this point ANY ideas or suggestions would be GREATLY appreciated. Erik Legacy N74FX ____________________________________ A Good Credit Score is 700 or Above. _See yours in just 2 easy steps!_ (http://pr.atwola.com/promoclk/100126575x1218822736x1201267884/aol?redir=http://www. freecreditreport.com/pm/default.aspx?sc=668072&hmpgID=62&bcd=febemailfooterNO6 2) **************A Good Credit Score is 700 or Above. See yours in just 2 easy steps! (http://pr.atwola.com/promoclk/100126575x1218822736x1201267884/aol?redir=http:%2F%2Fwww.freecreditreport.com%2Fpm%2Fdefault.aspx%3Fsc%3D668072%26hmpgID %3D62%26bcd%3DfebemailfooterNO62) -------------------------------1235573285 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
Erik,
 
Remember that the sequence valve is really a check valve that does not=20 allow "up" pressurized fluid to reach the door retraction cylinder unti= l it=20 is defeated by the plunger being depressed.  If the sequence=20 valve internal seals (o-rings) or extension spring are less than=20 perfect, perhaps a certain pressure allows some fluid by the check valve, bu= t=20 then the spring is able to re-seat it.  Maybe a sequence valve overhaul= is=20 in order.
 
Scott Krueger=20 AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL=20 (KARR)

In a message dated 2/25/2009 7:12:20 A.M. Central Stand= ard=20 Time, asw20747@aol.com writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
We have come up with an interesting problem while doing a recent=20 annual.  Was wondering if anyone might have some ideas?
 
Background:
 
We have a well built and well maintained Legacy that has been flying=20= for=20 about 2 years with just under 300 hrs on it. We are doing the (second) ann= ual=20 inspection and on the gear swing found that the nose gear retracts first,=20= then=20 the left main followed by the right main.  When the right main went u= p it=20 did so it with a chatter or shudder, most noticeable, at first, with=20= the=20 inner gear door.  In other words, it went up but not smoothly like th= e=20 other gear or as it has ALWAYS done in the past.
 
In an attempt to trouble shoot the problem we disconnected the i= nner=20 gear door and checked for ease of movement, binding etc..  All was=20 perfectly smooth with no binding or resistance of any kind.  We=20= then=20 retracted the gear without the inner door connected.  We still notice= a=20 consistent chatter in the right main AND in the inner gear door actua= tor=20 cylinder, moving without the inner gear door attached.  We then took=20= the=20 sequencing valve out of the picture by using a piece of doweling pushed up= on=20 the sequencing valve as the main gear retracted (inner door was=20 still disconnected) and now noticed a smooth operation of the ge= ar=20 and the inner door actuator.
 
We have checked that the sequencing valve makes good solid contact wi= th=20 the gear. We checked the up side hydro pressure and it was 1100 psi.=20= We=20 ran this problem by Lancair technical (Ross) and he suggested we= =20 bump up the hydro pressure to not more than 1,500 psi up to see if that ma= de=20 any difference.  We boosted it temporarily up to 1,425=20 psi  nd there were NO changes.
 
Does any one have an idea of what may be going on?  We have= =20 considered air in the system but with no leaks and the system operating fo= r=20 quite some time with no problems and many cycles, would air in the system=20 still be a possibility?  How about the sequencing valve, seems pretty= =20 simple, they either work or they don't, could that be an issue? Since we h= ave=20 been involved in this problem the issue has been consistent, never=20 intermittent, and never involved the other gear.
 
At this point ANY ideas or suggestions would be GREATLY=20 appreciated.   

Erik

Legacy
N74FX

A Good Credit Score is 700 or Above. See yours in just 2 easy steps!= -------------------------------1235573285--