Return-Path: Received: from [24.25.9.100] (HELO ms-smtp-01-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.2.5) with ESMTP id 574941 for flyrotary@lancaironline.net; Mon, 20 Dec 2004 21:36:47 -0500 Received-SPF: none receiver=logan.com; client-ip=24.25.9.100; envelope-from=echristley@nc.rr.com Received: from nc.rr.com (cpe-065-187-248-049.nc.rr.com [65.187.248.49]) by ms-smtp-01-eri0.southeast.rr.com (8.12.10/8.12.7) with ESMTP id iBL2aFKj028895 for ; Mon, 20 Dec 2004 21:36:15 -0500 (EST) Message-ID: <41C78BFA.8000206@nc.rr.com> Date: Mon, 20 Dec 2004 21:35:38 -0500 From: Ernest Christley User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040113 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=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Symantec AntiVirus Scan Engine 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. -- http://www.ernest.isa-geek.org/ "This is by far the hardest lesson about freedom. It goes against instinct, and morality, to just sit back and watch people make mistakes. We want to help them, which means control them and their decisions, but in doing so we actually hurt them (and ourselves)."