X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 26 Dec 2013 08:22:41 -0500 Message-ID: X-Original-Return-Path: Received: from nm29-vm3.bullet.mail.ne1.yahoo.com ([98.138.91.159] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with SMTP id 6652469 for lml@lancaironline.net; Wed, 25 Dec 2013 04:07:01 -0500 Received-SPF: none receiver=logan.com; client-ip=98.138.91.159; envelope-from=chris_zavatson@yahoo.com Received: from [98.138.101.128] by nm29.bullet.mail.ne1.yahoo.com with NNFMP; 25 Dec 2013 09:06:26 -0000 Received: from [98.138.88.239] by tm16.bullet.mail.ne1.yahoo.com with NNFMP; 25 Dec 2013 09:06:26 -0000 Received: from [127.0.0.1] by omp1039.mail.ne1.yahoo.com with NNFMP; 25 Dec 2013 09:06:26 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 556446.38737.bm@omp1039.mail.ne1.yahoo.com Received: (qmail 40807 invoked by uid 60001); 25 Dec 2013 09:06:26 -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:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=yKb32yyC8u+mD5cGUkHh7cU5CbQ4mjkFz8DxbJjvyooiz33cMKhw+79r4/5dDELkG43WyTjcsFJmqm373+mhDrEi2iNL3WVluirNw9re+/gGS20NbbX8B9u5kbr0h90UKO/7b56x1LEGZVdHFnTQb7zMtFNOCcUFpJjxSwhWsCo=; X-YMail-OSG: mDZ2NY4VM1nYFFiQDpxUTJbHn8nQyksXTDeOSVqSD3PRWY5 BFMRgOOkEUK_8Q6PlqAyjJMMQ8c_CNrj8BUDoR8uOMjygveZR0dDtgdb18bw bOVkowcyvhkY0QErgYixpydK8b7yoVMaHfkVTxMYmnBSZjhAUzX_tlS440Mg klG8aE5cIUcYQlLaeLTL_HHlz7dLXyDkDwRhlYFfdxx4IKjrcY_p_NyMhvlG 9zAKtRV5DXOtLacaDHn1CKTtrF_oC1V93TFsUkd1Qe7Wxx2DCOIwVFDd2QPf I0TLALZyMtTb58MMTC4N4KXzs6_v6ObMySzyIrEEog4Y_w7BXhw_xYRAE_EF TTaYp1.FNkJtqXpgR.4JkvXbU4MgWXpgZebEFCYQFDIus5MyKsKsL489K8I9 Yw07OgMG6sJUNKkPIpcJ2Z1p9imHPrei2pZx0lIYBMA74To7hz_8t7dQhji_ i9kU5LRbUeU67bbPWuhUgNK7sOjSDORYjZTequZ9NzYjF7cJ_BgegGqZ38Tg luHVHetxiD3Ga5rW5MJipmpEsJs_sSVjKhFP5k_RC7OTmROu2JAeCAyFhqnk YUpphnAl8Y0nn1vl.VML3oKMYPECZd0T5jzgY670LpRv6KfkwofsKhPvFDgr 63RTJFZpD.s3w8cLC.Bix2PSiotSa6PzKBeO5T0WtqtdrBGbiOaFV4xyg8KB PKrcc0FC2Dj9uJPqEMSxYkc.fta1BDwFzyc8UaR5jCycWonbkaRsDc.tLZub IXvJX8PXdZovCQrodj9ot8ND8sGC5Zn0l6kSQ349sBmeEnQa.wS5.8qMETgO _ONSa4yNu2u8luhGW0BpSUYrB4cwI9lrQdboycOm27bO44aFmig-- Received: from [172.14.16.72] by web121604.mail.ne1.yahoo.com via HTTP; Wed, 25 Dec 2013 01:06:26 PST X-Rocket-MIMEInfo: 002.001,TWFyaywKVGhlIHNwZWVkIHZzLiBhbHRpdHVkZSBjdXJ2ZSByZXByZXNlbnRzIHdpZGUgb3BlbiB0aHJvdHRsZSAoV09UKSBjcnVpc2Ugc3BlZWQuwqDCoFdoaWxlIHRoZSBhY3R1YWzCoHZhbHVlcyBhcmUgdW5pcXVlIHRvIHRoZSBhaXJmcmFtZSBkcmFnIGFuZCBpbmR1Y3Rpb24gcHJlc3N1cmUgcmVjb3Zlcnkgb2YgTjkxQ1osIHRoZSB0cmVuZHMgYXJlIHVuaXZlcnNhbC4KVGhlIGN1cnZlwqBpcyBzZXQgYnkgdGhlwqB3ZWlnaHQsIHJwbSBhbmQgT0FUIChzdGFuZGFyZCBhdG1vcy4gKy8tIHh4IGRlZykgY2EBMAEBAQE- X-Mailer: YahooMailWebService/0.8.172.614 References: X-Original-Message-ID: <1387962386.8658.YahooMailNeo@web121604.mail.ne1.yahoo.com> X-Original-Date: Wed, 25 Dec 2013 01:06:26 -0800 (PST) From: Chris Zavatson Reply-To: Chris Zavatson Subject: Re: [LML] Re: Debunking myth of flying fast into headwind X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-36511695-558872656-1387962386=:8658" ---36511695-558872656-1387962386=:8658 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Mark,=0AThe speed vs. altitude curve represents wide open throttle (WOT) cr= uise speed.=C2=A0=C2=A0While the actual=C2=A0values are unique to the airfr= ame drag and induction pressure recovery of N91CZ, the trends are universal= .=0AThe curve=C2=A0is set by the=C2=A0weight, rpm and OAT (standard atmos. = +/- xx deg) called out=C2=A0in the legend.=C2=A0=C2=A0Weight, rpm=C2=A0and = OAT, combined with engine, propeller and=C2=A0airframe data, produce the cr= uise performance curve of interest -or series of curves for sensitivity stu= dies.=0AThe=C2=A055, 65, and 75% power lines are added as a reference.=C2= =A0=C2=A0These are not necessarily tied to a specific=C2=A0rpm, but simply = represent percentage of rated engine power, 99, 117, and 135.=0AThe indicat= ed air speed curve and fuel economy were added as a curiosity given the cur= rent LML discussion.=C2=A0 The fuel economy curve=C2=A0uses actual flow dat= a from=C2=A0my carbureted engine.=C2=A0=C2=A0 Injected, even ROP, will be m= uch better.=C2=A0 Headwinds or tailwinds=C2=A0are also=C2=A0incorporated in= the fuel economy output, but none are shown.=C2=A0 The best range or L/D p= oint can be seen where the fuel economy line rolls over at about 120=C2=A0K= IAS in the first chart.=C2=A0 Engine speed was reduced to 2300 rpm to help = move this point to the left.=C2=A0 Reducing throttle is another means of pu= lling this point to the left, or to a lower altitude.=0Ahope that helps cla= rify,=0AChris=0A=0AChris Zavatson=0AN91CZ=0A360std=0Ahttp://www.n91cz.net/= =0A=C2=A0=C2=A0 =0A=0A=0A=0AOn Tuesday, December 24, 2013 11:06 AM, Mark Sl= etten wrote:=0A =0AChris,=0A=0ACan you give an examp= le of chart use? Where do I enter and which way do I proceed to find perfor= mance?=0A=0AThanks,=0A=0A--Mark=0A=0A=0A=0AOn Tue, Dec 24, 2013 at 6:42 AM,= Chris Zavatson wrote:=0A=0Anot sure the attachm= ents made it last time.=0A>Chris Zavatson=0A>=0A>=0A>=0A>On Monday, Decembe= r 23, 2013 10:33 AM, Chris Zavatson wrote:=0A> = =0A>The section on range in =E2=80=9CHandbook for Naval Aviators=E2=80=9D d= oes a=0Agood job comparing the various propulsion types with respect to ach= ieving=0Amaximum range.=C2=A0 While discussing=0Apropeller driven aircraft = with reciprocating engines, it mentions that engine=0Aoperating limitations= may actually drive achievable range.=C2=A0 This is indeed the case given t= he speed at=0Abest L/D for the 360, for example, is about 120 KIAS (weight = dependent) and it=0Aonly requires about 50 hp at low altitudes.=C2=A0 At su= ch low power and low altitude, engine efficiency is rather=0Apoor.=C2=A0 An= d as Gary mentioned, we tend to=0Aplace a relatively high value on speed.= =C2=A0 We can extract a good compromise by flying at higher altitudes.=C2= =A0 As the indicated air speed reduces with=0Aaltitude, range continues to = increase.=C2=A0 At WOT, reaching best L/D may still not be practical due to= the very=0Ahigh altitude required =E2=80=93 unless we are really, really h= eavy, as in carrying an=0Aextra 350 gallons of gas.=C2=A0 Throttling=0Aback= on power or pulling back engine speed is an option.=C2=A0 Since power has = already reduced naturally at=0Aaltitude, less power reduction is needed.=C2= =A0 One can also simply satisfy the need for speed and accept reduced range= .=0A>I superimposed fuel economy (fuel flow taken from a=0Acarburetor with = poor mixture distribution =E2=80=93 about a 20% hit) and indicated air=0Asp= eed on performance charts for the stated conditions.=C2=A0 Peak economy occ= urs very near the 120 KIAS=0Amark.=C2=A0 Further reductions in power or=0Ai= ncrease in weight will pull this point to lower altitudes.=0A>Given all thi= s I tend to fly high so I can save gas and=0Astill go fast.=0A>Chris=0AZava= tson=0A>N91CZ=0A>360std=0A>http://www.n91cz.net/=0A>=0A>=0A>=0A>=0A>=0A>=0A= >=0A>=0A>=0A>=0A>=0A>On Monday, December 16, 2013 6:45 AM, Mark Sletten wrote:=0A> =0A>Check Aerodynamics for Naval Aviators. T= he figure on page 169 and the accompanying text on page 170 will answer you= r question.=0A>=0A>=0A>http://www.faa.gov/regulations_policies/handbooks_ma= nuals/aviation/media/00-80T-80.pdf=0A>=0A>=0A>=0A>--Mark=0A>=0A>=0A>=0A>On = 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 m= atter the wind direction. Case in point I logged a 7.5 in a king air 200 fl= ying 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 800= lbs to spare.=0A>>=0A>>Anyhow the guy next to me wanted to push it up sayi= ng we would spend less time bucking the wind but I owned the plane today an= d flew what I perceived a Max range AOA (no AOA installed) of about 3 degre= es nose up and kept pulling the throttles back to keep her their. This atti= tude comes from 7 yrs in king airs and knowing the charts. But I don't have= the aero background to counter his argument.=0A>>=0A>>Can anyone help me o= ut with research or otherwise?=0A>>=0A>>I know their is a number of TPS gra= ds and much smarter aviators than I.=0A>>=0A>>George=0A>>=0A>>=0A>>=0A>>Sen= t from my iPhone=0A>>--=0A>>For archives and unsub http://mail.lancaironlin= e.net:81/lists/lml/List.html=0A>>=0A>=0A>=0A> =0A>=0A> =0A>--=0A>For= archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html=0A= >=0A> ---36511695-558872656-1387962386=:8658 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Ma= rk,
The speed v= s. altitude curve represents wide open throttle (WOT) cruise speed. &n= bsp;While th= e actual values are unique to the airframe drag and induction pressure= recovery of N91CZ, the trends are universal.
The curve is set by the weight, rpm and OAT (standa= rd atmos. +/- xx deg) called out in the legend.  Weight, rpm and OAT, combined with engine, propeller and airframe data, = produce the cruise performance curve of interest -or series of curves for s= ensitivity studies.
The 55, 65, and 75% power lines are added as a reference. &n= bsp;These are not necessarily tied to a specific rpm, but simply repre= sent percentage of rated engine power, 99, 117, and 135.
The indicated air speed curve and= fuel economy were added as a curiosity given the current LML discussion.&n= bsp; The fuel economy curve uses actual flow data from my carbure= ted engine.   Injected, even ROP, will be much better.  Head= winds or tailwinds are also incorporated in the fuel economy output, but none are shown.  The best range or L/D point can be seen = where the fuel economy line rolls over at about 120 KIAS in the first = chart.  Engine speed was reduced to 2300 rpm to help move this point t= o the left.  Reducing throttle is another means of pulling this point = to the left, or to a lower altitude.
hope that helps= clarify,
Chris

Chris Zavatson
N91CZ
360std
  

On Tuesd= ay, December 24,=0A 2013 11:06 AM, Mark Sletten <mwsletten@gmail.com>= wrote:
Chris,

Can you give an example of chart use? Where do I enter= and which way do I proceed to find performance?

Thanks,

--Mark
<= /div>
=0A

On Tue, Dec 24, 2013 at = 6:42 AM, Chris Zavatson <chris_zavatson@yahoo.com> w= rote:
=0A
<= div class=3D"yiv1122171736ms__id1247" style=3D"font-family: bookman old sty= le, new york, times, serif; font-size: 14pt;">
not sure the attac= hments made it last time.
Chris Zavatson

=0A
=
=0A On Monday, December 2= 3, 2013 10:33 AM, Chris Zavatson <chris_zavatson@yahoo.com> wrote:
=0A
=0A=0A
The section on range in =E2= =80=9CHandbook for Naval Aviators=E2=80=9D does a=0Agood job comparing the = various propulsion types with respect to achieving=0Amaximum range.&n= bsp; While discussing=0Apropeller driven aircraft with reciprocating= engines, it mentions that engine=0Aoperating limitations may actually driv= e achievable range.  This is indeed the case given the sp= eed at=0Abest L/D for the 360, for example, is about 120 KIAS (weight depen= dent) and it=0Aonly requires about 50 hp at low altitudes. =0AAt such low power and low altitude, engine efficiency is rather=0Apoor= .  And as Gary mentioned, we tend to=0Aplace a relatively= high value on speed. =0AWe can extract a good compromise= by flying at higher altitudes.  As the indicated air spe= ed reduces with=0Aaltitude, range continues to increase. =0AAt WOT, reaching best L/D may still not be practical due to the very=0Ah= igh altitude required =E2=80=93 unless we are really, really heavy, as in c= arrying an=0Aextra 350 gallons of gas.  Throttling=0Aback= on power or pulling back engine speed is an option.  Sin= ce power has already reduced naturally at=0Aaltitude, less power reduction = is needed. =0AOne can also simply satisfy the need for sp= eed and accept reduced range.
=0A=0A
I superimposed fuel economy (fuel flow taken f= rom a=0Acarburetor with poor mixture distribution =E2=80=93 about a 20% hit= ) and indicated air=0Aspeed on performance charts for the stated conditions= .  Peak economy occurs very near the 120 KIAS=0Amark.  Further reductions in power or=0Aincrease in weight will pu= ll this point to lower altitudes.
=0A=0A
<= font face=3D"Calibri" size=3D"3">Given all this I tend to fly high so I can= save gas and=0Astill go fast.
=0A= =0A
Chris=0AZavatson
= =0A=0A
N91CZ
=0A=0A
360std
=0A=0A

=0A


=0A

=0A=0A


=0A
On Monday, December 16, 2013 6:45 AM, Mark Sletten <mwsletten@gmail.com> w= rote:
=0A
Chec= k Aerodynamics for Naval Aviators. The figure on page 169 and the ac= companying=0A text on page 170 will answer your question.


--Mark


On Mon, Dec 16, 2013 at 7:00 AM, George Wehrung <gw5@me.com> wrot= e:
=0A=0A
Hey guys,
=0A
=0AOn long range flights I always fly a Max range profile no matt= er the wind direction. Case in point I logged a 7.5 in a king air 200 flyin= g 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 800 lb= s to spare.
=0A=0A=0A
=0AAnyhow the guy= next to me wanted to push it up saying we would spend less time bucking th= e wind but I owned the plane today and flew what I perceived a Max range AO= A (no AOA installed) of about 3 degrees nose up and kept pulling the thrott= les back to keep her their. This attitude comes from 7 yrs in king airs and= knowing the charts. But I don't have the aero background to counter his ar= gument.
=0A=0A=0A
=0ACan anyone help me= out with research or otherwise?
=0A
= =0AI know their is a number of TPS grads and much smarter aviators than I.<= br clear=3D"none">=0A
=0AGeorge
=0A
=0A
=0A
=0ASent from my = iPhone
=0A--
=0AFor archives and unsub http://mail.lancaironline.net:81/lists/lml/List.h= tml
=0A





=0A
--
=0AFor archives and unsub http://mail.lancaironline.net:81/lists/lml/List.htm= l
=0A



=
---36511695-558872656-1387962386=:8658--