X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 16 Oct 2007 18:52:24 -0400 Message-ID: X-Original-Return-Path: Received: from [64.233.178.240] (HELO hs-out-2021.google.com) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTP id 2390173 for lml@lancaironline.net; Tue, 16 Oct 2007 15:29:41 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.233.178.240; envelope-from=akadamson@gmail.com Received: by hs-out-2021.google.com with SMTP id k27so339685hsc for ; Tue, 16 Oct 2007 12:29:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:from:to:references:subject:date:message-id:mime-version:content-type:content-transfer-encoding:x-mailer:x-mimeole:thread-index:in-reply-to:sender; bh=TayahuDgqWEYUfOpt/NMAQxplEJzm24AXStN1vIufKQ=; b=OZu4E/1twL9epElWfcWzn4x14NPGqBTf8kotO8nzcA0hmnh33/eUndP4ZjAc6tbLz5x8EuhAcWVLof0cor+xwCVtnIFQCyydBajvfOtfO7PcaYMG1JhHzrmQk9x95x/Trw6vJjAH+JayequH7Di+7z47gMrXgHq4oxxdTeGV310= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:from:to:references:subject:date:message-id:mime-version:content-type:content-transfer-encoding:x-mailer:x-mimeole:thread-index:in-reply-to:sender; b=OoEVt0q1q7nSR4svJmn/FV9GEz9Y9/bTmXE2FKkJY3GFmScfTe0c9JUojaFDmDAIjmHA4PoY19QTrgiJQfTStZ88idK7ef1CvQx/OEyrRQkds67htHd5VFc8PKGKskgvB+Z6veFVyhDg1+5HF2F3gm/oLQzXgnuqVRdGotXLtQc= Received: by 10.90.118.12 with SMTP id q12mr9677103agc.1192562943452; Tue, 16 Oct 2007 12:29:03 -0700 (PDT) X-Original-Return-Path: Received: from Typhoon ( [76.97.53.219]) by mx.google.com with ESMTPS id n26sm8640799ele.2007.10.16.12.29.01 (version=SSLv3 cipher=RC4-MD5); Tue, 16 Oct 2007 12:29:01 -0700 (PDT) From: "Alan Adamson" X-Original-To: "'Lancair Mailing List'" References: Subject: RE: [LML] Re: prop drag X-Original-Date: Tue, 16 Oct 2007 15:29:03 -0400 X-Original-Message-ID: <04cf01c8102a$d0576b40$2a01a8c0@highrf.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Office Outlook 11 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 Thread-Index: AcgQJ4kZnvU/WHJyRB6IF5OKtZsVmQAAt9OA In-Reply-To: X-Original-Sender: Alan Adamson Bill, most props for non-turbine applications don't exactly go to feather... They are usually called "counterweighted" props and the counterweight use centrifugal force to move the blades to a "course pitch", but not full feather. A specific governor is required with these type of props... A "standard" governor won't work with them (at least as it relates to letting the blades move on loss of oil pressure. I think it's Hartzel that has a pretty good description on all of this on their website. NOTE, the counterweighted prop is *lots* more money than a non-counterweighted one and will require a special spinner so the spinner clears the counterweights. Hope some of this is helpful. Alan -----Original Message----- From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Bill Wade Sent: Tuesday, October 16, 2007 3:06 PM To: lml@lancaironline.net Subject: [LML] Re: prop drag My ignorance is showing but from what I've read if you have a non-feathering prop the blades will go to flat pitch if oil pressure is lost. I haven't experimented to find a value but once RPM drops below a certain point (as in throttled back for landing) the governor becomes ineffective, does it not? If the prop wasn't windmilling it should go to flat pitch. If it was turning would the speed be sufficient to allow pitch change or would it also be at flat pitch? I'm considering a feathering prop but I've never used one. What happens at startup and low RPM's- is there a control detent to prevent the prop from going feathered? -Bill Wade -- For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html