X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from sccrmhc11.comcast.net ([204.127.202.55] verified) by logan.com (CommuniGate Pro SMTP 4.3c5) with ESMTP id 913453 for flyrotary@lancaironline.net; Sun, 24 Apr 2005 20:38:32 -0400 Received-SPF: none receiver=logan.com; client-ip=204.127.202.55; envelope-from=kenpowell@comcast.net Received: from 204.127.205.150 ([204.127.205.150]) by comcast.net (sccrmhc11) with SMTP id <20050425003747011007uc6ae>; Mon, 25 Apr 2005 00:37:47 +0000 Received: from [68.51.45.41] by 204.127.205.150; Mon, 25 Apr 2005 00:37:46 +0000 From: kenpowell@comcast.net To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: Upper Airspeed Data on Rotary-Powered Van's RV Date: Mon, 25 Apr 2005 00:37:46 +0000 Message-Id: <042520050037.28336.426C3BDA0006CDE800006EB0220075115004040A99019F020A05@comcast.net> X-Mailer: AT&T Message Center Version 1 (Dec 17 2004) X-Authenticated-Sender: a2VucG93ZWxsQGNvbWNhc3QubmV0 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="NextPart_Webmail_9m3u9jl4l_28336_1114389466_0" --NextPart_Webmail_9m3u9jl4l_28336_1114389466_0 Content-Type: text/plain Content-Transfer-Encoding: 8bit Hi Dave (and welcome John), I agree that this (TAS) is really strange and not intuitive. But consider the source - Van himself!!! When I read this in RVator I had doubts but I gotta go with John on this unless we hear from another impeccable source to the contray. TAS it is!!!! Call Van if you need more info; I doubt any of us (do we have any aeronautical engineers on the list? I know we have every other flavor of engineer here!) have the knowledge to debate this with Van. -- Ken Powell Bryant, Arkansas 501-847-4721 -------------- Original message -------------- rv-7a wrote: However, my bubble was busted by the Van's RVAtor article on flutter (6th issue 2004). Van’s engineers instructed their readership on flutter – that Vne is really a TAS limit, not an IAS limit. A US Air Force pilot and RV commuter corroborated the Van’s article by telling his disturbing TAS flutter story (first 2005 RVAtor issue). If you haven’t read this, I recommend it for all pilots, no matter what they fly. I’ve decided to follow Van’s advice and restrict my upper airspeed to limit to 200 KTS TAS in smooth air. I don’t want to be a test pilot. Therefore, I’m reconsidering my plan to supercharge the Renesis/RD-1C installation. The weight penalty may not be worth climb performance increase if 200 KTS TAS cruise can be easily achieved with a normally aspirated installation. If I can collect empirical data from RV Rotary flyers, it would sure help my decision. Thanks, John Burns rv-7a@comcast.net http://mywebpages.comcast.net/jgburns/Engine/Engine.html for my engine webpage. Intuitively it does not make sense that flutter is a TAS issue. I would be interested in reviewing the engineering/hypothesis on which this is based. The plane "feels" IAS.. not TAS... you can have a TAS of 400 and still have only an IAS of 200 (if you are high enough).. IAS is the dynamic pressure and state that the aircraft experiences. So.. I would be greatly interested in knowing why the engineers are making this claim and what its basis is. Dave >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html --NextPart_Webmail_9m3u9jl4l_28336_1114389466_0 Content-Type: text/html Content-Transfer-Encoding: 8bit

Hi Dave (and welcome John),

I agree that this (TAS) is really strange and not intuitive. But consider the source - Van himself!!! When I read this in RVator I had doubts but I gotta go with John on this unless we hear from another impeccable source to the contray. TAS it is!!!! Call Van if you need more info; I doubt any of us (do we have any aeronautical engineers on the list? I know we have every other flavor of engineer here!) have the knowledge to debate this with Van.

--
Ken Powell
Bryant, Arkansas
501-847-4721

-------------- Original message --------------

rv-7a wrote:

However, my bubble was busted by the Van's RVAtor article on flutter (6th issue 2004). Van’s engineers instructed their readership on flutter – that Vne is really a TAS limit, not an IAS limit. A US Air Force pilot and RV commuter corroborated the Van’s article by telling his disturbing TAS flutter story (first 2005 RVAtor issue). If you haven’t read this, I recommend it for all pilots, no matter what they fly.

I’ve decided to follow Van’s advice and restrict my upper airspeed to limit to 200 KTS TAS in smooth air. I don’t want to be a test pilot. Therefore, I’m reconsidering my plan to supercharge the Renesis/RD-1C installation. The weight penalty may not be worth climb performance increase if 200 KTS TAS cruise can be easily achieved with a normally aspirated installation. If I can collect empirical data from RV Rotary flyers, it would sure help my decision.

Thanks,

John Burns

rv-7a@comcast.net

http://mywebpages.comcast.net/jgburns/Engine/Engine.html for my engine webpage.

Intuitively it does not make sense that flutter is a TAS issue. I would be interested in reviewing the engineering/hypothesis on which this is based. The plane "feels" IAS.. not TAS... you can have a TAS of 400 and still have only an IAS of 200 (if you are high enough).. IAS is the dynamic pressure and state that the aircraft experiences. So.. I would be greatly interested in knowing why the engineers are making this claim and what its basis is.

Dave
>>  Homepage:  http://www.flyrotary.com/

>>  Archive:   http://lancaironline.net/lists/flyrotary/List.html

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