X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 50 [XX] Return-Path: Received: from rwcrmhc15.comcast.net ([204.127.192.85] verified) by logan.com (CommuniGate Pro SMTP 5.1.8) with ESMTP id 2047558 for flyrotary@lancaironline.net; Wed, 16 May 2007 10:28:10 -0400 Received-SPF: none receiver=logan.com; client-ip=204.127.192.85; envelope-from=rlwhite@comcast.net Received: from rlwhite (c-68-35-160-229.hsd1.nm.comcast.net[68.35.160.229]) by comcast.net (rwcrmhc15) with SMTP id <20070516142721m15007h3u7e>; Wed, 16 May 2007 14:27:31 +0000 Date: Wed, 16 May 2007 08:27:56 -0600 From: Bob White To: "Rotary motors in aircraft" Subject: Re: TAS calibration Message-Id: <20070516082756.ea87cc74.rlwhite@comcast.net> In-Reply-To: References: X-Mailer: Sylpheed 2.4.0 (GTK+ 2.10.11; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 16 May 2007 07:13:04 -0600 Bob White wrote: > On Wed, 16 May 2007 8:02:09 -0500 > wrote: > > > > > > > > > From: Ernest Christley > > > Date: 2007/05/16 Wed AM 07:33:52 EST > > > To: "Rotary motors in aircraft" > > > Subject: [FlyRotary] Re: TAS calibration > > > > > > Bulent Aliev wrote: > > > > Here is another question for the electronics gurus. > > > > I noticed on the EM2 TAS is always 15-18 K while the plane is still? I > > > > thought it is supposed to be zero? If so, I could not see a way to > > > > adjust it? > > > > Buly > > > > > > > That number happens to be somewhat close to the value of the > > > acceleration that a prop introduces to the air. Where is your pitot > > > located? That may be what the sensors are actually seeing. > > > > > > > My pitot is in the nose (CZ MK-IV) and the prop at the back. Plane sitting in the hangar. No air movement. > > Buly > > > Hi Buly, > > I'm pretty sure there is a calibration setting in the EM2. Mine wasn't > zero either and I seem to recall adjusting it. I'll have to look thru > my notes to see if I can find it. > > Bob W. > Air speed is channel 14 in the calibration menu (Hold 3, press 1). When you first select the channel, take a look at the current value of the sensor. Change the sensor offset to match that value. That will give a zero reading on the display. You may still need to adjust the scale factor, but will need some flying data to know. OAT and altitude need to be correct also. Bob W. -- N93BD - Rotary Powered BD-4 - http://www.bob-white.com 3.8 Hours Total Time and holding Cables for your rotary installation - http://www.roblinphoto.com/shop/