X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 26 Oct 2006 23:35:11 -0400 Message-ID: X-Original-Return-Path: Received: from imo-m26.mx.aol.com ([64.12.137.7] verified) by logan.com (CommuniGate Pro SMTP 5.1.1) with ESMTP id 1506384 for lml@lancaironline.net; Thu, 26 Oct 2006 13:34:36 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.7; envelope-from=Sky2high@aol.com Received: from Sky2high@aol.com by imo-m26.mx.aol.com (mail_out_v38_r7.6.) id q.cc9.137a1c7 (41809) for ; Thu, 26 Oct 2006 13:34:05 -0400 (EDT) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Thu, 26 Oct 2006 13:34:04 EDT Subject: Re: [LML] Re: Prop Feathering X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1161884044" X-Mailer: 9.0 Security Edition for Windows sub 5330 X-Spam-Flag: NO -------------------------------1161884044 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 10/26/2006 12:04:31 P.M. Central Standard Time, marv@lancaironline.net writes: I want oil pressure tanks to place the prop in course pitch, low RPM. if I have an engine or oil pump loss. Kevin, Consider the following: If the engine quits running but is still turning there should be enough oil pressure generated to pull the prop to coarse pitch. Perhaps the question should be, "How low can the rpm go and still provide enough pressure to control the prop?" If oil is lost from the engine and it is still powered it will soon seize and stop the prop - not as good as coarse pitch but better than the drag disk from a spinning prop at flat pitch. I can't quite understand how the complex plumbing with check valves and a pressure tank could take over and keep the prop in coarse pitch if the only seriously dangerous condition is where there was no engine power, no oil and the engine was not seized but still turning, thus no control over the prop after it went to flat pitch. Maybe an electric prop is the answer. Scott Krueger AKA Grayhawk Lancair N92EX IO320 SB 89/96 Aurora, IL (KARR) A man has got to know his limitations. -------------------------------1161884044 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
In a message dated 10/26/2006 12:04:31 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 want oil pressure tanks to place the prop in course pitch, low  RPM.=20 if
I have an engine or oil pump loss.
Kevin,
 
Consider the following:
 
If the engine quits running but is still turning there should be enough= oil=20 pressure generated to pull the prop to coarse pitch.  Perhaps the=20 question should be, "How low can the rpm go and still provide enough=20 pressure to control the prop?"
 
If oil is lost from the engine and it is still powered it will soon sei= ze=20 and stop the prop - not as good as coarse pitch but better than the drag dis= k=20 from a spinning prop at flat pitch.
 
I can't quite understand how the complex plumbing with check valve= s=20 and a pressure tank could take over and keep the prop in coarse=20 pitch if the only seriously dangerous condition is where there was no=20 engine power, no oil and the engine was not seized but still turni= ng,=20 thus no control over the prop after it went to flat pitch.  Maybe an=20 electric prop is the answer.=20
 
Scott Krueger=20 AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL (KARR)

A m= an=20 has got to know his limitations.
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