X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-db03.mx.aol.com ([205.188.91.97] verified) by logan.com (CommuniGate Pro SMTP 5.4.6) with ESMTP id 5644084 for flyrotary@lancaironline.net; Mon, 09 Jul 2012 12:24:53 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.91.97; envelope-from=bktrub@aol.com Received: from mtaomg-ma01.r1000.mx.aol.com (mtaomg-ma01.r1000.mx.aol.com [172.29.41.8]) by imr-db03.mx.aol.com (8.14.1/8.14.1) with ESMTP id q69GOEnM019087 for ; Mon, 9 Jul 2012 12:24:14 -0400 Received: from core-dub005c.r1000.mail.aol.com (core-dub005.r1000.mail.aol.com [172.29.164.82]) by mtaomg-ma01.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 9ADFEE000094 for ; Mon, 9 Jul 2012 12:24:14 -0400 (EDT) References: To: flyrotary@lancaironline.net Subject: Re: [FlyRotary] Re: First lift off with single rotor In-Reply-To: X-MB-Message-Source: WebUI MIME-Version: 1.0 From: bktrub@aol.com X-MB-Message-Type: User Content-Type: multipart/alternative; boundary="--------MB_8CF2C0669D3489C_1CC0_124784_webmail-d076.sysops.aol.com" X-Mailer: AOL Webmail 36542-STANDARD Received: from 23.25.136.85 by webmail-d076.sysops.aol.com (205.188.181.102) with HTTP (WebMailUI); Mon, 09 Jul 2012 12:24:13 -0400 Message-Id: <8CF2C0669C5004A-1CC0-536E3@webmail-d076.sysops.aol.com> X-Originating-IP: [23.25.136.85] Date: Mon, 9 Jul 2012 12:24:14 -0400 (EDT) x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20110426; t=1341851054; bh=aDyD901+myaEqrUQM/XhwEBn4hnSrKm+bwvYXQGXFVg=; h=From:To:Subject:Message-Id:Date:MIME-Version:Content-Type; b=EV9ngY5N04QvxpOvp281ntT5WjDnwmh2hmPoTtr6Lmccy2mDsFMiuXYPV9u+aIe5e 5GI5KbPARTXduILu4skgh/qlEAEe9oVzkNagnaDKZfkngYhD2Tw83dIrkH6hd02a2M zc/jZUSfrU/9YYNheLfDl+EHcmqrZAz8YcPu8d6Y= X-AOL-SCOLL-SCORE: 0:2:416237888:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d29084ffb05ae72d5 This is a multi-part message in MIME format. ----------MB_8CF2C0669D3489C_1CC0_124784_webmail-d076.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="us-ascii" What type of engine controller do you have? And what RPM is the engine at w= hen it starts to sputter. I had the same sort of issue- the engine ran fin= e on the ground, but after liftoff, at about 50 feet, the engine would star= t to backfire and sputter. The issue was the polarity of the CAS was revers= ed. I am using the RWS EC2. Maybe the same issue with you, maybe not. It wa= s a real buzzkill, let me tell you. I wouldn't say it scared me, but I woul= d say that I was doing a lot of soul searching about that time.=20 Brian Trubee -----Original Message----- From: Ernest Christley To: Rotary motors in aircraft Sent: Mon, Jul 9, 2012 9:13 am Subject: [FlyRotary] Re: First lift off with single rotor Richard Sohn wrote: Cleared the ground for a brief period today. As far as the airplane is concerned, everything is good. CG seems to be right on the spot. Much better as it was 12 years ago at the first flight with the SOOB. Here is the reason why it was not a flight. A few days ago when I started high speed taxi, as soon as it picked up air speed, the engine started to sputter and almost cut out totally. This was at the same RPM as at a run up, where it does not do that. With a wiggly tail dragger as the Avid is, there was no way reading enough instrument for making a preliminary analysis. I recorded the instrument panel with a GoPro at 2sec intervals. Looking at the first pictures, the answer came up right away, increasing pressure under the cowl where the intake for the engine is located. Like the EGT shot up over 1600 just before the sputtering started. Since my radiator air is going to the outside of the cowling, there was no impact on cooling. Btw cooling is really good. At an OAT of 95F, oil and water stayed at around 170F no matter what I did. =20 For todays runs, I taped the inlet around the prop hub shut. Sure enough, the sputtering occurred at higher airspeed, and was not as total, however, EGT was still going to around 1600. =20 The conclusion is, I have to open the cowling exits a lot. I don't get it. The pressure under the cowl sounds like it would be a good= =20 hing, because it sounds like it is enough o cause the engine to lean out. If the cooling isn't a problem, why wouldn= 't=20 ou just enrichen the mixture to ccommodate the extra air and accept the increase in power? -- omepage: http://www.flyrotary.com/ rchive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.h= tml ----------MB_8CF2C0669D3489C_1CC0_124784_webmail-d076.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="us-ascii"
What type of engine controller do you have? And what RPM is the engine= at when it starts to sputter. I had the same sort of issue-  the engi= ne ran fine on the ground, but after liftoff, at about 50 feet, the engine = would start to backfire and sputter. The issue was the polarity of the CAS = was reversed. I am using the RWS EC2. Maybe the same issue with you, maybe = not. It was a real buzzkill, let me tell you. I wouldn't say it scared me, = but I would say that I was doing a lot of soul searching about that time. <= /div>
 
Brian Trubee


= -----Original Message-----
From: Ernest Christley <echristley@att.net>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Mon, Jul 9, 2012 9:13 am
Subject: [FlyRotary] Re: First lift off with single rotor

Richar=
d Sohn wrote:
> Cleared the ground for a brief period today. As far as the airplane is
> concerned, everything is good. CG seems to be right on the spot. Much
> better as it was 12 years ago at the first flight with the SOOB.
> Here is the reason why it was not a flight. A few days ago when I
> started high speed taxi, as soon as it picked up air speed, the engine
> started to sputter and almost cut out totally. This was at the same RP=
M
> as at a run up, where it does not do that. With a wiggly tail dragger =
as
> the Avid is, there was no way reading enough instrument for making a
> preliminary analysis. I recorded the instrument panel with a GoPro at
> 2sec intervals.
> Looking at the first pictures, the answer came up right away, increasi=
ng
> pressure under the cowl where the intake for the engine is located. Li=
ke
> the EGT shot up over 1600 just before the sputtering started. Since my
> radiator air is going to the outside of the cowling, there was no impa=
ct
> on cooling. Btw cooling is really good. At an OAT of 95F, oil and wate=
r
> stayed at around 170F no matter what I did.
> =20
> For todays runs, I taped the inlet around the prop hub shut. Sure
> enough, the sputtering occurred at higher airspeed, and was not as
> total, however, EGT was still going to around 1600.
> =20
> The conclusion is, I have to open the cowling exits a lot.

I don't get it.  The pressure under the cowl sounds like it would be a good=
=20
thing, because it sounds like it is enough
to cause the engine to lean out.  If the cooling isn't a problem, why would=
n't=20
you just enrichen the mixture to
accommodate the extra air and accept the increase in power?

--
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