X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from lrcmmta09-srv.windstream.net ([166.102.165.81] verified) by logan.com (CommuniGate Pro SMTP 5.3.4) with ESMTP id 4180831 for flyrotary@lancaironline.net; Sat, 27 Mar 2010 11:26:21 -0400 Received-SPF: pass receiver=logan.com; client-ip=166.102.165.81; envelope-from=montyr2157@windstream.net Return-Path: X-WS-COS: WSOB804 X-Cloudmark-Category: Undefined:Undefined X-Cloudmark-Analysis: v=1.1 cv=wPx7ZEuc9DKFVlM8qgf+ED5LeflKyolDFVtFXtW6PZQ= c=1 sm=0 a=lEKczduQO_Ml75UlmKwA:9 a=Kuy1ND9N8mE8xuSyzO7Np8QRYR4A:4 a=wPNLvfGTeEIA:10 a=EBgEhpl7ktsHgQRhFZAA:9 a=seIaHy5wHdMJzu1JNBEA:7 a=EON7ItgqZJCd_jCnFMWA8DjOpncA:4 a=Tqu7KJNV67v1yzmK454j5w==:117 X-Cloudmark-Score: 0 Authentication-Results: lrcmmta09 smtp.user=montyr2157; auth=pass (LOGIN) Received: from [98.20.242.90] ([98.20.242.90:60339] helo=newbox) by lrcmmta09 (envelope-from ) (ecelerity 2.2.2.45 r()) with ESMTPA id DF/19-24866-9732EAB4; Sat, 27 Mar 2010 10:25:45 -0500 Message-ID: <4A4B460D06C441588D064B70F06DE2EC@newbox> From: "MONTY ROBERTS" To: "Rotary motors in aircraft" References: Subject: Adaptor plate rivets - Al' 20B Date: Sat, 27 Mar 2010 10:25:16 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0086_01CACD97.CB14BC50" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5843 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 This is a multi-part message in MIME format. ------=_NextPart_000_0086_01CACD97.CB14BC50 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Great info Al, I haven't been able to read through all the posts because of work = lately, so forgive me if this has already been addressed.=20 The thing that jumps out at me is that the problem is worse on the 20B. = Of course they have more total power, but they also have 1/3 more cyclic = loading due to the extra power pulse per rev. What matters for machine = design and fatigue rating is not only the magnitude but the number of = cycles. A 20B would have roughly the same peak loading, but is 33% older = in fatigue cycle terms than a two rotor. Any TBO issues will show up = first on the 20B installations because of this. Monty ------=_NextPart_000_0086_01CACD97.CB14BC50 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Great info Al,
 
I haven't been able to read through all = the posts=20 because of work lately, so forgive me if this has already been = addressed.=20
 
The thing that jumps out at me is that = the problem=20 is worse on the 20B. Of course they have more total power, but they = also=20 have 1/3 more cyclic loading due to the extra power pulse per rev. = What=20 matters for machine design and fatigue rating is not only the magnitude = but the=20 number of cycles. A 20B would have roughly the same peak loading, but is = 33%=20 older in fatigue cycle terms than a two rotor. Any TBO issues will = show=20 up first on the 20B installations because of = this.
 
Monty
------=_NextPart_000_0086_01CACD97.CB14BC50--