X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from an-out-0708.google.com ([209.85.132.240] verified) by logan.com (CommuniGate Pro SMTP 5.1.10) with ESMTP id 2190418 for flyrotary@lancaironline.net; Fri, 20 Jul 2007 21:57:43 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.132.240; envelope-from=rotary.thjakits@gmail.com Received: by an-out-0708.google.com with SMTP id b2so196713ana for ; Fri, 20 Jul 2007 18:57:08 -0700 (PDT) DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=Buo7+idQQwsNbfI7P5jAD9yD8QspWh6v2ICd+Zy2Z2U10ExjfEyWRKX4bJbUEWmQc0d7nj8YD4q9KW0tWT11P7g4ykvs+Tfhn0pibcBRakEW8Ml2KmexK104RaIWf9kEdgSIbe7LdIDmxA+gZeK++qXoH0XTPI2aG3QdHzSa/7I= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=tfCYyoxVXBALcyfTScQvF+YWqnQqCYVyUlWB5BepXYL9ypTasuINXF+O6aEZSnwXfnEWeT3CEWnFnkmsHKY8lB83iowo46WBT6VgYRs3mzjdD0pfeQ4G0jilKL3LWfN0XJ3LhvwofWTt0IWFi+6Lyn/tWc9k+twOqjXkBRiQies= Received: by 10.100.13.12 with SMTP id 12mr542994anm.1184983028277; Fri, 20 Jul 2007 18:57:08 -0700 (PDT) Received: by 10.100.197.17 with HTTP; Fri, 20 Jul 2007 18:57:08 -0700 (PDT) Message-ID: <63163d560707201857l156bf3c6s46d6b7c33b2e8073@mail.gmail.com> Date: Fri, 20 Jul 2007 20:57:08 -0500 From: "Thomas Jakits" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: FW: [FlyRotary] Re: Thrust measure. In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_176894_32269322.1184983028197" References: ------=_Part_176894_32269322.1184983028197 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline > """"snip" > > Ok... I've seen countless little red biplanes hang from their prop at > airshows; certainly the prop is "stalled", and knowing that the engine/prop > combination can produce thrust to counter the gross weight in order to allow > the plane to hover is useful information to this small group of pilots. But > how many of us really need that info? > > > > """snip" > > > > If that prop is stalled the bird comes down!! Just because the plane has > zero speed, does not mean the prop is stalled. > > > > Ok, now you are splitting hairs. J You know what I meant. In fact, you > used the same term in the second line in the quoted message above to > describe a prop that is in fact not stalled. But if you are going to split > hairs, some part of every prop is stalled at almost every airspeed, except > an Elippse, and that's only when the plane is going the designed speed at > the designed RPM. > > > My intention was not to split hairs, unless you meant "stall" in a different way (...which I did not catch, ...:)) in the little red airplane context. I meant stall in the DA-9, as the prop was effectively stalled and acceleration was sloooow. Hanging on the prop, no chance for a stall, just "helicopter mode" with a rather inefficient "short rotor" - don't think it would autorotate :) (Though that would be a serious show!!) TJ ------=_Part_176894_32269322.1184983028197 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline

""""snip"

Ok... I've seen countless little red biplanes hang from their prop at airshows; certainly the prop is "stalled", and knowing that the engine/prop combination can produce thrust to counter the gross weight in order to allow the plane to hover is useful information to this small group of pilots. But how many of us really need that info?

"""snip"

If that prop is stalled the bird comes down!! Just because the plane has zero speed, does not mean the prop is stalled.

Ok, now you are splitting hairs. J You know what I meant. In fact, you used the same term in the second line in the quoted message above to describe a prop that is in fact not stalled. But if you are going to split hairs, some part of every prop is stalled at almost every airspeed, except an Elippse, and that's only when the plane is going the designed speed at the designed RPM.

My intention was not to split hairs, unless you meant "stall" in a different way (...which I did not catch, ...:)) in the little red airplane context.

I meant stall in the DA-9, as the prop was effectively stalled and acceleration was sloooow. Hanging on the prop, no chance for a stall, just "helicopter mode" with a rather inefficient "short rotor" - don't think it would autorotate :) (Though that would be a serious show!!)

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