Return-Path: Sender: "Marvin Kaye" To: lml@lancaironline.net Date: Wed, 30 Mar 2005 01:33:43 -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 4.3c3) with ESMTP id 829449 for lml@lancaironline.net; Tue, 29 Mar 2005 23:11:17 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.11; envelope-from=Sky2high@aol.com Received: from Sky2high@aol.com by imo-m19.mx.aol.com (mail_out_v37_r5.33.) id q.30.6f6ab838 (16930) for ; Tue, 29 Mar 2005 23:10:27 -0500 (EST) From: Sky2high@aol.com X-Original-Message-ID: <30.6f6ab838.2f7b80b3@aol.com> X-Original-Date: Tue, 29 Mar 2005 23:10:27 EST Subject: Re: [LML] Re: nose gear door X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1112155827" X-Mailer: 9.0 Security Edition for Windows sub 5000 -------------------------------1112155827 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 3/28/2005 10:41:28 P.M. Central Standard Time, marv@lancaironline.net writes: I thought that this (vibration) might be the problem and tried various ways of tightening the fit (used rubber between the door and airframe etc) but apparently ground observers say my door hangs completely open in flight and sometimes I would hear a short cycle from the pump and the buzzing would stop abruptly when it slammed shut. The current problem is that on retracting the gear it doesn't close at all. I used to have the problem with back pressure in the down line..this manifested as the nose gear door closing in 3 quick jerks as the pressure bled off during retraction. I'm pretty certain the current problem commenced after I replaced the valve assembly which solved problem number one (the jerky closure). I wonder if the spool valve problem manifests itself in various ways??? Do you have any Gerhard, If the nose gear door sequence valve is not adjusted properly, then all of these problems could occur. 1. not closing or sometimes closing - depends on whether the nose gear actually trips the valve. 2. intermittent could be because pressure leakage when the valve is just opened the weeest bit, the hi pressure bleeds down a bit (trying to close the door), pump runs, repeat this same sequence a few times until everything is finally done in. Remember that the sequence valve is a defeated check valve. Fluid can always run from OUT to IN as when the door opens and the fluid from the hi pressure side of the actuator runs back to the reservoir. The fluid is not allowed to run from IN to OUT until the plunger is depressed, thus defeating the "check valve" function. Scott Krueger -------------------------------1112155827 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

In a message dated 3/28/2005 10:41:28 P.M. Central Standard Time,=20 marv@lancaironline.net writes:

<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I=20 thought that this (vibration) might be the problem and tried
various wa= ys=20 of tightening the fit (used rubber between the door and airframe
etc) b= ut=20 apparently ground observers say my door hangs completely open in
flight= and=20 sometimes I would hear a short cycle from the pump and the buzzing
woul= d=20 stop abruptly when it slammed shut. The current problem is that=20 on
retracting the gear it doesn't close at all.

I=20= used=20 to have the problem with back pressure in the down line..this
manifeste= d as=20 the nose gear door closing in 3 quick jerks as the pressure bled
off du= ring=20 retraction. I'm pretty certain the current problem commenced after
I=20 replaced the valve assembly which solved problem number one (the=20 jerky
closure). I wonder if the spool valve problem manifests itself in= =20 various
ways??? Do you have any

Gerhard,

If the nose gear door sequence valve is not adjusted properly, then all= of=20 these problems could occur.

1. not closing or sometimes closing - depends on whether the nose= =20 gear actually trips the valve.

2. intermittent could be because pressure leakage when the v= alve=20 is just opened the weeest bit, the hi pressure bleeds down a bit (trying to=20 close the door), pump runs, repeat this same sequence a few times until= =20 everything is finally done in.

Remember that the sequence valve is a defeated check valve. Fluid= can=20 always run from OUT to IN as when the door opens and the fluid from the = ;hi=20 pressure side of the actuator runs back to the reservoir. The fluid is= not=20 allowed to run from IN to OUT until the plunger is depressed, thus defeating= the=20 "check valve" function.

Scott Krueger

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