X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sat, 26 Jan 2013 02:07:10 -0500 Message-ID: X-Original-Return-Path: Received: from nm16.access.bullet.mail.mud.yahoo.com ([66.94.237.217] verified) by logan.com (CommuniGate Pro SMTP 6.0.1) with ESMTPS id 6030077 for lml@lancaironline.net; Fri, 25 Jan 2013 20:33:12 -0500 Received-SPF: neutral receiver=logan.com; client-ip=66.94.237.217; envelope-from=browncc1@verizon.net Received: from [66.94.237.197] by nm16.access.bullet.mail.mud.yahoo.com with NNFMP; 26 Jan 2013 01:32:38 -0000 Received: from [98.138.85.46] by tm8.access.bullet.mail.mud.yahoo.com with NNFMP; 26 Jan 2013 01:32:38 -0000 Received: from [127.0.0.1] by smtp103.vzn.mail.ne1.yahoo.com with NNFMP; 26 Jan 2013 01:32:38 -0000 X-Yahoo-Newman-Id: 96390.23405.bm@smtp103.vzn.mail.ne1.yahoo.com X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: ns_aV3oVM1l1QlszcsDAPgFLFi1OWpfYiUCu0XQpyWhdczl jeHsKy0zIDUlUgAlYH__a60P49pdhGBIC_aQj7Hnlyl_vOW_qmeb4ToUO2Cg YPzxfOjLpMd4rDL3sikeggGsid9PXsCAuxvdE.8qyqelOHcxTAUVRRc1G3rg zsCoY6p5M.Qhl.kplM9bXl890gQ1ZN6wLQ2savmtAIoif4JEqG88WhV4PzGh UhWnr2Yemf.k5rwhX_HRUqvwHVnH1GUb1b4E9tjMcZEeB8KqjoM_8etl6PHv 8GpFHWzsmcRB_0DocOHZGIHd7lgnHbFiWt1zbj7v0JZ.IRriL5HglgwAemDm .elp.wFXnfrZJuJhnjg1y8BkWgsVbXQFxFoWN3DhmgIBAsnoMtZ3j1Dv7S.T soGtrWaO5zLDfiMOzlMwQncME9o8NNxAUIyeQaTZ7ssOp1qDBTf7Wwg8PDmh 4P7KWCk2SxOXlWYtTKmx6HUnzSnY- X-Yahoo-SMTP: F49l9g6swBC0R9n8vJIbm7Tf3P8Xlmia8rHIwTlO__Ml Received: from chass-imac-2.home (browncc1@72.64.105.53 with plain) by smtp103.vzn.mail.ne1.yahoo.com with SMTP; 26 Jan 2013 01:32:37 +0000 UTC From: Charles Brown Mime-Version: 1.0 (Apple Message framework v1085) Content-Type: multipart/alternative; boundary=Apple-Mail-2-752150565 Subject: Prop efficiency -- Hartzell X-Original-Date: Fri, 25 Jan 2013 19:32:36 -0600 In-Reply-To: X-Original-To: "Lancair Mailing List" References: X-Original-Message-Id: X-Mailer: Apple Mail (2.1085) --Apple-Mail-2-752150565 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii I have Hartzell's efficiency analysis for their 3-blade and 2-blade = props for the Legacy / IO550, if anyone's interested. (I suspect that = they would apply equally to any airframe and engine combination). On Jan 25, 2013, at 1:32 PM, Bill Bradburry wrote: Fred, I have never been great at reading graphs, but the diagonal line is = airspeed, not HP corrected for prop efficiency. That is the vertical = line. Or am I wrong?? How do you do this if you have an alternative engine and have no idea of = what your HP is? It seems that you are guessing about the prop = efficiency and I would have to do the same for HP. Perhaps if someone = gets a FP drag number for the Lancair Legacy FG, I could work backwards = and find the HP? Bill --Apple-Mail-2-752150565 Content-Transfer-Encoding: 7bit Content-Type: text/html; charset=us-ascii

I have Hartzell's efficiency analysis for their 3-blade and 2-blade props for the Legacy / IO550, if anyone's interested. (I suspect that they would apply equally to any airframe and engine combination).

On Jan 25, 2013, at 1:32 PM, Bill Bradburry wrote:

Fred,

I have never been great at reading graphs, but the diagonal line is airspeed, not HP corrected for prop efficiency. That is the vertical line. Or am I wrong??

How do you do this if you have an alternative engine and have no idea of what your HP is? It seems that you are guessing about the prop efficiency and I would have to do the same for HP. Perhaps if someone gets a FP drag number for the Lancair Legacy FG, I could work backwards and find the HP?

Bill

--Apple-Mail-2-752150565--