Return-Path: Received: from relay01.roc.ny.frontiernet.net ([66.133.131.34] verified) by logan.com (CommuniGate Pro SMTP 4.2.5) with ESMTP id 574976 for flyrotary@lancaironline.net; Mon, 20 Dec 2004 22:03:18 -0500 Received-SPF: pass receiver=logan.com; client-ip=66.133.131.34; envelope-from=canarder@frontiernet.net Received: from filter01.roc.ny.frontiernet.net (filter01.roc.ny.frontiernet.net [66.133.131.176]) by relay01.roc.ny.frontiernet.net (Postfix) with ESMTP id E6B3D10201 for ; Tue, 21 Dec 2004 03:02:46 +0000 (UTC) Received: from relay01.roc.ny.frontiernet.net ([66.133.131.34]) by filter01.roc.ny.frontiernet.net (filter01.roc.ny.frontiernet.net [66.133.131.176]) (amavisd-new, port 10024) with LMTP id 08311-15-44 for ; Tue, 21 Dec 2004 03:02:46 +0000 (UTC) Received: from [127.0.0.1] (67-137-85-246.dsl2.cok.tn.frontiernet.net [67.137.85.246]) by relay01.roc.ny.frontiernet.net (Postfix) with ESMTP id 71B2DFFF0 for ; Tue, 21 Dec 2004 03:02:46 +0000 (UTC) Message-ID: <41C79256.4070602@frontiernet.net> Date: Mon, 20 Dec 2004 21:02:46 -0600 From: Jim Sower User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7) Gecko/20040514 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: George Graham glide update References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Antivirus: avast! (VPS 0451-2, 12/17/2004), Outbound message X-Antivirus-Status: Clean X-Virus-Scanned: by amavisd-new-20040701 (2.0) at filter01.roc.ny.frontiernet.net <... all has to come out for CG reasons. ...> I'd be really ambivalent about a sprag clutch or any "disengage" mechanism on the grounds of reliability. Seems like gawd awful failure modes. Just a theory ... Jim S. Ernest Christley wrote: > Jim Sower wrote: > >> I would guess toward the lower end (15:1) as an initial guess. I do >> believe that a freewheeling prop should give a HUGE improvement in >> glide range over a windmilling prop driving the engine. Look at the >> force/power required to spin your engine at the windmill rpm through >> the PSRU. Then look at the tiny force/power required to spin the >> prop alone if it is freewheeling. Now, with that differential in >> power required figure out how much force (drag) it takes to equal >> that power at glide airspeed. The difference could nearly be like >> having the belly board down. The difference between engine at idle >> and engine dead IS like having the belly board down. >> >> Hard to verify. Nobody has much experience with freewheeling prop. >> What few data points there are might be suspect on account of the guy >> too real busy flying to get good data. >> >> How many people COULD test that condition? ... Jim S. >> >> > > The guy that sold me my engine was planning on it. He has the whole > clutch assembly in there. Told me that I could put in a lever and > disengage the prop for starting. Too bad it all has to come out for > CG reasons. >