X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from smtpauth03.mail.atl.earthlink.net ([209.86.89.63] verified) by logan.com (CommuniGate Pro SMTP 4.3c5) with ESMTP id 913320 for flyrotary@lancaironline.net; Sun, 24 Apr 2005 18:05:18 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.86.89.63; envelope-from=Dastaten@earthlink.net Received: from [24.238.206.157] (helo=earthlink.net) by smtpauth03.mail.atl.earthlink.net with asmtp (Exim 4.34) id 1DPpDN-0006jc-WC for flyrotary@lancaironline.net; Sun, 24 Apr 2005 18:04:34 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=simple; s=test1; d=earthlink.net; h=Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=Jmph2oWLh1EYlMMB1OSW7eRVsWpYaOGb/JnTImGP1qAXrE67Ms52Ez7I3qPAKCv3; Message-ID: <426C1773.9080706@earthlink.net> Date: Sun, 24 Apr 2005 17:02:27 -0500 From: David Staten User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 (ax) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Upper Airspeed Data on Rotary-Powered Van's RV References: In-Reply-To: Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit X-ELNK-Trace: 9a30bff84e6cb88f95c85d38d22416599ef193a6bfc3dd488332d8c9cba784ce00dfc6f7a920febc7510c956a98deb90350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 24.238.206.157

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