X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 24 Dec 2013 14:06:24 -0500 Message-ID: X-Original-Return-Path: Received: from mail-qe0-f50.google.com ([209.85.128.50] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTPS id 6651765 for lml@lancaironline.net; Tue, 24 Dec 2013 10:38:32 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.128.50; envelope-from=mwsletten@gmail.com Received: by mail-qe0-f50.google.com with SMTP id 1so6623662qec.9 for ; Tue, 24 Dec 2013 07:37:57 -0800 (PST) MIME-Version: 1.0 X-Received: by 10.224.171.196 with SMTP id i4mr54030490qaz.38.1387899477111; Tue, 24 Dec 2013 07:37:57 -0800 (PST) Received: by 10.229.125.20 with HTTP; Tue, 24 Dec 2013 07:37:56 -0800 (PST) In-Reply-To: References: X-Original-Date: Tue, 24 Dec 2013 09:37:56 -0600 X-Original-Message-ID: Subject: Re: [LML] Re: Debunking myth of flying fast into headwind From: Mark Sletten X-Original-To: Lancair Mailing List Content-Type: multipart/alternative; boundary=001a11c2ef54513c5c04ee498772 --001a11c2ef54513c5c04ee498772 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Chris, Can you give an example of chart use? Where do I enter and which way do I proceed to find performance? Thanks, --Mark On Tue, Dec 24, 2013 at 6:42 AM, Chris Zavatson w= rote: > not sure the attachments made it last time. > Chris Zavatson > > > On Monday, December 23, 2013 10:33 AM, Chris Zavatson < > chris_zavatson@yahoo.com> wrote: > The section on range in =93Handbook for Naval Aviators=94 does a good j= ob > comparing the various propulsion types with respect to achieving maximum > range. While discussing propeller driven aircraft with reciprocating > engines, it mentions that engine operating limitations may actually drive > achievable range. This is indeed the case given the speed at best L/D > for the 360, for example, is about 120 KIAS (weight dependent) and it onl= y > requires about 50 hp at low altitudes. At such low power and low > altitude, engine efficiency is rather poor. And as Gary mentioned, we > tend to place a relatively high value on speed. We can extract a good > compromise by flying at higher altitudes. As the indicated air speed > reduces with altitude, range continues to increase. At WOT, reaching > best L/D may still not be practical due to the very high altitude require= d > =96 unless we are really, really heavy, as in carrying an extra 350 gallo= ns > of gas. Throttling back on power or pulling back engine speed is an > option. Since power has already reduced naturally at altitude, less > power reduction is needed. One can also simply satisfy the need for > speed and accept reduced range. > I superimposed fuel economy (fuel flow taken from a carburetor with poor > mixture distribution =96 about a 20% hit) and indicated air speed on > performance charts for the stated conditions. Peak economy occurs very > near the 120 KIAS mark. Further reductions in power or increase in > weight will pull this point to lower altitudes. > Given all this I tend to fly high so I can save gas and still go fast. > Chris Zavatson > N91CZ > 360std > www.N91CZ.net > > > > > > > On Monday, December 16, 2013 6:45 AM, Mark Sletten > wrote: > Check *Aerodynamics for Naval Aviators*. The figure on page 169 and the > accompanying text on page 170 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 Wehrung wrote: > > Hey guys, > > On long range flights I always fly a Max range profile no matter the wind > direction. Case in point I logged a 7.5 in a king air 200 flying from Laj= es > Azores to St Johns Newfoundland today. The winds got up to 122 knots in t= he > face. But with the internal ferry tank we made it with 800 lbs to spare. > > Anyhow the guy next to me wanted to push it up saying we would spend less > time bucking the wind but I owned the plane today and flew what I perceiv= ed > a Max range AOA (no AOA installed) of about 3 degrees nose up and kept > pulling the throttles 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 argument. > > Can anyone help me out with research or otherwise? > > I know their is a number of TPS grads and much smarter aviators than I. > > George > > > > Sent from my iPhone > -- > For archives and unsub > http://mail.lancaironline.net:81/lists/lml/List.html > > > > > > > > -- > For archives and unsub > http://mail.lancaironline.net:81/lists/lml/List.html > > --001a11c2ef54513c5c04ee498772 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable
Chris,

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

Thanks,

--Mark


On Tue, Dec 24, 2013 at 6:42 AM, Chris Z= avatson <chris_zavatson@yahoo.com> wrote:
not sure the attachments made it last time.
Chris Zavatson


On Monday, December 23, 2013 10:33 AM, Chris Zavatso= n <chris_z= avatson@yahoo.com> wrote:
<= div style=3D"font-size:14pt;font-family:bookman old style,new york,times,se= rif">
The section on range in =93Handbook for Naval Aviators=94 does a good job comparing the various propulsion types with respect to achieving maximum range.=A0 While discussing propeller driven aircraft with reciprocating engines, it mentions that engi= ne operating limitations may actually drive achievable range.=A0 = This is indeed the case given the speed at best L/D for the 360, for example, is about 120 KIAS (weight dependent) and= it only requires about 50 hp at low altitudes.=A0 At such low power and low altitude, engine efficiency is rather poor.=A0 And as Gary mentioned, we tend to place a relatively high value on speed.=A0 We can extract a good compromise by flying at higher altitudes.=A0 As the indicated air speed reduces with altitude, range continues to increase.=A0 At WOT, reaching best L/D may still not be practical due to the very high altitude required =96 unless we are really, really heavy, as in carryi= ng an extra 350 gallons of gas.=A0 Throttling back on power or pulling back engine speed is an option.=A0 Si= nce power has already reduced naturally at altitude, less power reduction is needed.=A0 One can also simply satisfy the need for speed and accept reduced ra= nge.
I superimposed fuel economy (fuel flow taken from a carburetor with poor mixture distribution =96 about a 20% hit) and indicate= d air speed on performance charts for the stated conditions.=A0 Peak= economy occurs very near the 120 KIAS mark.=A0 Further reductions in power or increase in weight will pull this point to lower altitudes.
Given all this I tend to fly high so I can save gas and still go fast.
Chris Zavatson
N91CZ
360std





On Monday, December 16, 2013 6:45 = AM, Mark Sletten <mwsletten@gmail.com> wrote:
Check Aerodynamics for Naval Aviators. The figure o= n page 169 and the accompanying text on page 170 will answer your question.

<= div>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:
Hey g= uys,

On long range flights I always fly a Max range profile no matter the wind d= irection. 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 800 lbs to spare.
Anyhow the guy next to me wanted to push it up saying we would spend less t= ime bucking the wind but I owned the plane today and flew what I perceived = a Max range AOA (no AOA installed) of about 3 degrees nose up and kept pull= ing the throttles 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 argument.

Can anyone help me out with research or otherwise?

I know their is a number of TPS grads and much smarter aviators than I.

George



Sent from my iPhone
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