X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 17 Dec 2013 08:18:00 -0500 Message-ID: X-Original-Return-Path: Received: from nm21.bullet.mail.ne1.yahoo.com ([98.138.90.84] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTPS id 6642011 for lml@lancaironline.net; Tue, 17 Dec 2013 07:26:12 -0500 Received-SPF: none receiver=logan.com; client-ip=98.138.90.84; envelope-from=casey.gary@yahoo.com Received: from [98.138.101.129] by nm21.bullet.mail.ne1.yahoo.com with NNFMP; 17 Dec 2013 12:25:37 -0000 Received: from [98.138.89.162] by tm17.bullet.mail.ne1.yahoo.com with NNFMP; 17 Dec 2013 12:25:37 -0000 Received: from [127.0.0.1] by omp1018.mail.ne1.yahoo.com with NNFMP; 17 Dec 2013 12:25:37 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 16683.48832.bm@omp1018.mail.ne1.yahoo.com Received: (qmail 42666 invoked by uid 60001); 17 Dec 2013 12:25:36 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Rocket-MIMEInfo:X-Mailer:Message-ID:Date:From:Reply-To:Subject:To:MIME-Version:Content-Type; b=KGpuaboLXKLThl2nDLgHT3Pjpb54r5k3nesKW/APJdiWSXW0wGb2K71qndynHegT4pJR6KP9wdBPmLlqzoxbcxkuMl2fnFrwUcJ90OYm7WJl0/5obBES/c0YZ+IDJdIzLL3NYHYHbZghY/EKHx5ASz8eKn67D6uFsxbzUazPgmk=; X-YMail-OSG: da2XVzUVM1ki4FtQ6u9jvmc.FEjXnZdM.l__g84Bjg2S90W FxEVe9iWewf8xjky6emt7bElACnakpTcR3dbHGLEW4V_Wc6AXTr3BOTDo79i eTFv9RJtkw_ZsYOlKgaTjjd_BOe90GmxffJg7vOOLF_6CeZGDqOEOrihUFox _8.fH2hHQzGIrOv5rh_WDqj502b6aTe8OeUd_dDOx2lYY4d8JnXB1_7C_RpM np2v3893TzDJyM6Z4zc.TxKz.ol0w2ZhCyaKAiTFdnmRnCgiugkHhWGDT9bj 37Zhts7xN4eA8t6yOt_FtflY23SEL_j6vBrgHLSHFG3yZii1K6q0YMcNBt0F zambeS5G3E5q3W41GAIcokB8Ht7dpQOpF9mpcg_Xxe1ofAxoHweSWvTr3HkD dwlln4.GSrQQTSSbrOx4cPWXlRcodFoDD93.QkxwTST8RuxTwOls.Bn8yRAB LWhz.AhTRfR_s1pd_RYExqeiZe0y5P81YMU1HVcZX6xf63LAAbZ.uUK4eTvG toYYAPSqEvtDZlPaJLywgME9ngWMKblDb1U4Rf2_ZCcRswYDwv0wLDkBIdm_ l3CE0JmKLyIo3ALCBN9U1XAuvRsgkFJUprMyAyztOFCLDL1zi6VEno0AXhzB CCtxrEuA_qXlI6ZulEuk5PZ_oXT13aNlQ_1bktadOhp4iRAYNPIKZxWq4vMJ drGGr9FYe7wPUZRcZm.TAa_u2j8fsq5YZ4ENbogM- Received: from [97.92.63.83] by web120103.mail.ne1.yahoo.com via HTTP; Tue, 17 Dec 2013 04:25:36 PST X-Rocket-MIMEInfo: 002.001,WWVzLCBhIGRpc2N1c3Npb24gb24gdGhlIGVmZmVjdCBvZiBhIGhlYWR3aW5kIGlzIHRoZXJlLCBidXQgSSdtIGFmcmFpZCB0aGUgYW5zd2VyIGlzbid0LiDCoFNvIEkgcHV0IHRvZ2V0aGVyIGEgY2FsY3VsYXRpb24gdGhhdCBmaWd1cmVkIGl0IG91dCBmb3IgYWlyc3BlZWRzIHR5cGljYWwgb2YgbXkgRVMuIMKgSXQgdHVybnMgb3V0IHRoYXQgd2l0aCB6ZXJvIHdpbmQgaXQgaXMgYWx3YXlzIG1vcmUgZWZmaWNpZW50IHRvIHNsb3cgZG93biwgYXQgbGVhc3QgY29tcGFyZWQgdG8gYW55ICJub3JtYWwiIGNydWkBMAEBAQE- X-Mailer: YahooMailWebService/0.8.170.612 X-Original-Message-ID: <1387283136.36239.YahooMailNeo@web120103.mail.ne1.yahoo.com> X-Original-Date: Tue, 17 Dec 2013 04:25:36 -0800 (PST) From: Gary Casey Reply-To: Gary Casey Subject: Re: [LML] Debunking myth of flying fast into headwind X-Original-To: Lancair Mailing List MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-955686164-606999158-1387283136=:36239" ---955686164-606999158-1387283136=:36239 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Yes, a discussion on the effect of a headwind is there, but I'm afraid the = answer isn't. =A0So I put together a calculation that figured it out for ai= rspeeds typical of my ES. =A0It turns out that with zero wind it is always = more efficient to slow down, at least compared to any "normal" cruise speed= . =A0But to be more realistic of what most of us might consider important, = I typically us a number I call "effectiveness", and that is the MPG times t= he speed squared. =A0After all, most of us value speed quite a bit. =A0For = effectiveness, you generally want to go fast. =A0For best MPG you usually w= ant to add around 1/3 the headwind component to your speed. =A0For me, that= means that while best MPG might be at 120 TAS with no wind, I would want t= o add 20 (maybe even 30) knots if I have a 60-knot headwind. =A0But above 1= 40 to 150 TAS, the MPG is always going down with increased speed, regardles= s of any reasonable headwind. =A0I never fly as slow as 120, so it means th= at going faster always reduces fuel economy, headwind or not. =A0As far as "e= ffectiveness", going faster gets to be a LOT better with a headwind. =A0Yes= , go faster into a headwind, but I don't think that means going from LOP to= ROP - that doesn't get enough speed to pay for itself. =A0And with a tailw= ind, definitely slow down - but I have a mental problem doing that!=0AGary = Casey=A0=0A=0A=0ACheck *Aerodynamics for Naval Aviators*. The figure on pag= e 169 and the=0Aaccompanying text on page 170 will answer your question.=0A= =0Ahttp://www.faa.gov/regulations_policies/handbooks_manuals/aviation/media= /00-80T-80.pdf=0A=0A--Mark=0A=0A=0AOn Mon, Dec 16, 2013 at 7:00 AM, George = Wehrung wrote:=0A=0A> Hey guys,=0A>=0A> On long range flights = I always fly a Max range profile no matter the wind=0A> direction. Case in = point I logged a 7.5 in a king air 200 flying from Lajes=0A> Azores to St J= ohns Newfoundland today. The winds got up to 122 knots in the=0A> face. But= with the internal ferry tank we made it with 800 lbs to spare.=0A>=0A> Any= how the guy next to me wanted to push it up saying we would spend less=0A> = time bucking the wind but I owned the plane today and flew what I perceived= =0A> a Max range AOA (no AOA installed) of about 3 degrees nose up and kept= =0A> pulling the throttles back to keep her their. This attitude comes from= 7=0A> yrs in king airs and knowing the charts. But I don't have the aero= =0A> background to counter his argument.=0A>=0A> Can anyone help me out wit= h research or otherwise?=0A>=0A> I know their is a number of TPS grads and = much smarter aviators than I.=0A>=0A> George=0A ---955686164-606999158-1387283136=:36239 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Yes, a discussion on the effect of a headwind is there, = but I'm afraid the answer isn't.  So I put together a calculation that= figured it out for airspeeds typical of my ES.  It turns out that wit= h zero wind it is always more efficient to slow down, at least compared to = any "normal" cruise speed.  But to be more realistic of what most of u= s might consider important, I typically us a number I call "effectiveness",= and that is the MPG times the speed squared.  After all, most of us v= alue speed quite a bit.  For effectiveness, you generally want to go f= ast.  For best MPG you usually want to add around 1/3 the headwind com= ponent to your speed.  For me, that means that while best MPG might be= at 120 TAS with no wind, I would want to add 20 (maybe even 30) knots if I have a 60-knot headwind.  But above 140 to 150 TAS, the MPG is a= lways going down with increased speed, regardless of any reasonable headwin= d.  I never fly as slow as 120, so it means that going faster always r= educes fuel economy, headwind or not.  As far as "effectiveness", goin= g faster gets to be a LOT better with a headwind.  Yes, go faster into= a headwind, but I don't think that means going from LOP to ROP - that does= n't get enough speed to pay for itself.  And with a tailwind, definite= ly slow down - but I have a mental problem doing that!
Gary Casey=  


Check *Aerodynamics for Naval Aviators*. The figure on page 169 and= the
accompanying text on page 1= 70 will answer your question.

http://www.faa.gov/regulations_policies/handbooks_manuals/aviation/media= /00-80T-80.pdf
--Mark


On Mon, Dec 16, 2013 at 7:00 AM, George W= ehrung <gw5@me.com> wrote:

&= gt; Hey guys,
= >
> On long range flights I always fly a Max= range profile no matter the wind
> direc= tion. Case in point I logged a 7.5 in a king air 200 flying from Lajes
> Azores to St Johns Newfoundland= today. The winds got up to 122 knots in the
> face. But with the internal ferry tank we made it with 80= 0 lbs to spare.
>
> Anyhow the guy next to me wanted to pu= sh it up saying we would spend less
> time bucking the wind but I owned the plane today and flew what I perceived
> a Max range AOA (no AOA instal= led) of about 3 degrees nose up and kept
> pulling the throttles back to keep her their. This attitude c= omes from 7
> yrs in king air= s and knowing the charts. But I don't have the aero
> background to counter his argument.
>
> Can a= nyone help me out with research or otherwise?
>
> I know t= heir is a number of TPS grads and much smarter aviators than I.
>
> George
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