X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 04 Jun 2009 12:02:11 -0400 Message-ID: X-Original-Return-Path: Received: from vms173001pub.verizon.net ([206.46.173.1] verified) by logan.com (CommuniGate Pro SMTP 5.2.14) with ESMTP id 3671437 for lml@lancaironline.net; Thu, 04 Jun 2009 08:29:03 -0400 Received-SPF: pass receiver=logan.com; client-ip=206.46.173.1; envelope-from=n5zq@verizon.net Received: from newness ([173.72.139.201]) by vms173001.mailsrvcs.net (Sun Java(tm) System Messaging Server 6.3-7.04 (built Sep 26 2008; 32bit)) with ESMTPA id <0KKP00KRARE8LR6A@vms173001.mailsrvcs.net> for lml@lancaironline.net; Thu, 04 Jun 2009 07:15:45 -0500 (CDT) X-Original-Message-id: From: "Bill" X-Original-To: "Lancair Mailing List" References: Subject: Re: [LML] L360 winglets X-Original-Date: Thu, 04 Jun 2009 08:16:07 -0400 MIME-version: 1.0 Content-type: multipart/alternative; boundary="----=_NextPart_000_0309_01C9E4EC.B5FCD3F0" X-Priority: 3 X-MSMail-priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5512 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 This is a multi-part message in MIME format. ------=_NextPart_000_0309_01C9E4EC.B5FCD3F0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Rob, I seem to recall that Charlie K. gathered data on a IV both with and = without winglets. Charlie, was the number 7 knots? That is, 7 knots = faster WITHOUT the winglets.=20 Several knowledgeable folks have responded that winglets are mostly an = advantage at very high altitudes, and this is true. I would add that my = conversations several years ago with some Boeing engineers indicated = that the exact shape and placement of winglets was ultra critical. = Probably not something that any of us could design and install in our = shop and have any hope of improving performance. Extensive wind tunnel = testing would be required to get it right. My wind tunnel (powered by = hot air) is out of service. To be successful, the winglets would need to = reduce drag by more than the increase in drag that they would = necessarily cause by increasing wetted area and weight. Imperfectly = done, they have the likely outcome of slowing you down. Keep it simple, = leave 'em off.=20 Rob, do you fly out of YPPH or YPJT? Bill Harrelson N5ZQ 320 1,650 hrs N6ZQ IV under construction I am building a L360 in Australia, and will soon have to make the = decision about what wing tips to use. The kit comes with the standard = tips. However, I have seen some Lancairs with winglets, and am wondering = whether they are worth the investment in time and money. Has anyone out = there in LML land done any research into the benefits of winglets? I am = interested particularly in before and after comparisons, both in terms = of speed and general handling. =20 Any info would be greatly appreciated. =20 Rob Stevens =20 Perth, Western Australia. ------=_NextPart_000_0309_01C9E4EC.B5FCD3F0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Hi Rob,

I seem to recall that Charlie K. = gathered data on a=20 IV both with and without winglets. Charlie, was the number 7 = knots? That=20 is, 7 knots faster WITHOUT the winglets.

Several knowledgeable folks have = responded that=20 winglets are mostly an advantage at very high altitudes, and this = is true.=20 I would add that my conversations several years ago with some Boeing = engineers=20 indicated that the exact shape and placement of winglets was ultra = critical.=20 Probably not something that any of us could design and install = in our shop=20 and have any hope of improving performance. Extensive wind tunnel = testing would=20 be required to get it right. My wind tunnel (powered by hot air) is out = of=20 service. To be successful, the winglets would need to reduce drag by = more than=20 the increase in drag that they would necessarily cause by=20 increasing wetted area and weight. Imperfectly done, they=20 have the likely outcome of slowing you down. Keep it simple, leave = 'em=20 off.

Rob, do you fly out of YPPH or = YPJT?

Bill Harrelson

N5ZQ 320 1,650 hrs

N6ZQ IV under = construction

I am=20 building a L360 in Australia, and will soon have to make the decision = about=20 what wing tips to use. The kit comes with the standard tips. However, = I have=20 seen some Lancairs with winglets, and am wondering whether they are = worth the=20 investment in time and money. Has anyone out there in LML land done = any=20 research into the benefits of winglets? I am interested particularly = in before=20 and after comparisons, both in terms of speed and general=20 handling.

Any=20 info would be greatly appreciated.

Rob=20 Stevens

Perth,=20 Western Australia.

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