X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from willowsprings.uwyo.edu ([129.72.10.31] verified) by logan.com (CommuniGate Pro SMTP 5.4c2) with ESMTPS id 4913082 for flyrotary@lancaironline.net; Sun, 20 Mar 2011 22:21:24 -0400 Received-SPF: none receiver=logan.com; client-ip=129.72.10.31; envelope-from=SBoese@uwyo.edu Received: from ponyexpress-ht2.uwyo.edu (ponyexpress-ht2.uwyo.edu [10.84.60.209]) by willowsprings.uwyo.edu (8.14.4/8.14.4) with ESMTP id p2L2KmbX025794 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL) for ; Sun, 20 Mar 2011 20:20:49 -0600 (MDT) (envelope-from SBoese@uwyo.edu) Received: from ponyexpress-mb5.uwyo.edu ([fe80::9813:248c:2d68:a28b]) by ponyexpress-ht2 ([10.84.60.209]) with mapi; Sun, 20 Mar 2011 20:20:12 -0600 From: "Steven W. Boese" To: Rotary motors in aircraft Date: Sun, 20 Mar 2011 20:20:03 -0600 Subject: RE: [FlyRotary] Re: Forced Landing. Thread-Topic: [FlyRotary] Re: Forced Landing. Thread-Index: AcvnYKL/LehuCv12QkaDvUYUFg/F9wACyeXg Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: multipart/alternative; boundary="_000_E1AA3B1AF41D8049B1E3FBD5E225626008892DF91Eponyexpressmb_" MIME-Version: 1.0 --_000_E1AA3B1AF41D8049B1E3FBD5E225626008892DF91Eponyexpressmb_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Bobby, I have not done any testing with a wideband O2 sensor. Unless the engine w= ere operating right on a threshold of a large untuned injector pulse width = change (staging is the only thing that comes to mind), it seems unlikely th= at the variation in O2 sensor would be associated with injector delay. Within the limits that were tested, the EGT increased with increased exhaus= t back pressure due to partial blockage. The mixture was somewhat rich and= no change in O2 sensor was seen. Lean mixtures were not investigated at t= hat time. Steve From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Beh= alf Of Bobby J. Hughes Sent: Sunday, March 20, 2011 7:46 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Forced Landing. Steve, Thanks for the offer. Actually I think it would be great if you could condu= ct a test. I had thought about a block off plate that could be pulled into = place with a long wire. This would allow a high power test run with a sudd= en blockage. It's the only way I can come up with to create a not so dramat= ic reinactment. Your test stand would be a better platform then the airplan= e. The engine was popping and shaking when the failure occurred. As best I = can remember my wideband O2 was off the scale lean but I'm not certain. Spe= aking of wideband O2's. My wideband has always jumping around a few 10ths o= r more. My EM3 get's a narrowband output from the wideband. The EM3's mixtu= re bar appears stable. Could the wideband be seeing a injector bounce assoc= iated with the injector delay? As an example when leaned for cruise, say 13= .2 it's often switching rapidally between 13.1 and 13.3. At this point the = engine seems reasonable smooth. The larger the bounce the less smooth the e= ngine becomes. Have you done any of your testing with a wideband? Bobby --_000_E1AA3B1AF41D8049B1E3FBD5E225626008892DF91Eponyexpressmb_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Bobby,

I have not done any testing with a = wideband O2 sensor. Unless the engine were operating right on a thres= hold of a large untuned injector pulse width change (staging is the only th= ing that comes to mind), it seems unlikely that the variation in O2 sensor = would be associated with injector delay.

&= nbsp;

Within the limits that were tested, the EGT in= creased with increased exhaust back pressure due to partial blockage. = The mixture was somewhat rich and no change in O2 sensor was seen. L= ean mixtures were not investigated at that time.

Steve

From: Rotary motors in aircraft [mail= to:flyrotary@lancaironline.net] On Behalf Of Bobby J. Hughes
S= ent: Sunday, March 20, 2011 7:46 PM
To: Rotary motors in airc= raft
Subject: [FlyRotary] Re: Forced Landing. <= /p>

Steve,

Thanks for the offer. Actually I= think it would be great if you could conduct a test. I had thought about a= block off plate that could be pulled into place with a long wire. Th= is would allow a high power test run with a sudden blockage. It’s the= only way I can come up with to create a not so dramatic reinactment. Your = test stand would be a better platform then the airplane. The engine was pop= ping and shaking when the failure occurred. As best I can remember my wideb= and O2 was off the scale lean but I’m not certain. Speaking of wideba= nd O2’s. My wideband has always jumping around a few 10ths or more. M= y EM3 get’s a narrowband output from the wideband. The EM3’s mi= xture bar appears stable. Could the wideband be seeing a injector bounce as= sociated with the injector delay? As an example when leaned for cruise, say= 13.2 it’s often switching rapidally between 13.1 and 13.3. At this p= oint the engine seems reasonable smooth. The larger the bounce the less smo= oth the engine becomes. Have you done any of your testing with a wideband? =

=

Bobb= y

= --_000_E1AA3B1AF41D8049B1E3FBD5E225626008892DF91Eponyexpressmb_--