X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mx2.netapp.com ([216.240.18.37] verified) by logan.com (CommuniGate Pro SMTP 5.3.3) with ESMTPS id 4152516 for flyrotary@lancaironline.net; Thu, 04 Mar 2010 15:48:08 -0500 Received-SPF: softfail receiver=logan.com; client-ip=216.240.18.37; envelope-from=echristley@nc.rr.com X-IronPort-AV: E=Sophos;i="4.49,582,1262592000"; d="scan'208";a="326337672" Received: from smtp1.corp.netapp.com ([10.57.156.124]) by mx2-out.netapp.com with ESMTP; 04 Mar 2010 12:47:33 -0800 Received: from [10.62.16.80] (ernestc-laptop.hq.netapp.com [10.62.16.80]) by smtp1.corp.netapp.com (8.13.1/8.13.1/NTAP-1.6) with ESMTP id o24KlWqK022459 for ; Thu, 4 Mar 2010 12:47:33 -0800 (PST) Message-ID: <4B901C64.7060801@nc.rr.com> Date: Thu, 04 Mar 2010 15:47:32 -0500 From: Ernest Christley Reply-To: echristley@nc.rr.com User-Agent: Thunderbird 2.0.0.23 (X11/20090817) MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Vance Jaqua and Propellers References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Bryan Winberry wrote: > Thanks Ernest, > Can you splain me one thin. How does the AoA change on a fixed pitch prop? > The blade move side to side. The airplane move forward (for non-aerobatic modes of flight). The AoA is affected by the relationship of the side-to-side and forward motions. Twirl a flat blade with the brakes locked. The AoA is zero degrees. With an engine out, and prop stopped and flat. The AoA is 90 degrees. Under normal operation. The AoA is a vector sum of the forward movement and the side-to-side movement.