X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 18 Sep 2013 08:32:29 -0400 Message-ID: X-Original-Return-Path: Received: from mail-pb0-f49.google.com ([209.85.160.49] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTPS id 6479391 for lml@lancaironline.net; Tue, 17 Sep 2013 17:19:38 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.160.49; envelope-from=keith.smith@gmail.com Received: by mail-pb0-f49.google.com with SMTP id xb4so6101034pbc.22 for ; Tue, 17 Sep 2013 14:19:02 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.68.178.227 with SMTP id db3mr3933717pbc.202.1379452742215; Tue, 17 Sep 2013 14:19:02 -0700 (PDT) Received: by 10.70.57.103 with HTTP; Tue, 17 Sep 2013 14:19:02 -0700 (PDT) In-Reply-To: References: X-Original-Date: Tue, 17 Sep 2013 17:19:02 -0400 X-Original-Message-ID: Subject: Re: [LML] Re: Lancair 320/360 performance and stability From: Keith Smith X-Original-To: Lancair Mailing List Content-Type: multipart/alternative; boundary=047d7b6735f0af30f104e69ade34 --047d7b6735f0af30f104e69ade34 Content-Type: text/plain; charset=ISO-8859-1 Scott, Are you able to provide a supplier for the material used for the gap seals? Any notes about the installation? An engineer from Lo Presti came across my airplane on the ramp one day at a fuel stop and was crawling over it. "Boy, not much left to do on this thing!" The only thing he mentioned was extending the ram air inlet to be much closer to the prop to maximize efficiency and the installation of gap seals. I do enough long trips that 6-8kias would be of interest to me, especially since I recently managed to hit headwinds over the course of 3 days of flying, even though I flew in all directions in those 3 degs (nuts, right?) Every day brought a new and exciting headwind. 'Doh! Keith On Sun, Sep 15, 2013 at 3:26 PM, wrote: > ** > Chris, > > Great research. > > In my small tailed 320, increased flap reflex experimentation did not > result in increased top end speed. The nose up pitch was increased, > requiring increased nose down trim - probably resulting in greater > empennage drag negating any reduction in drag from the greater reflex. Of > course, we would have to discuss the angle of incidence of the small tail > and its relationship to the elevator correcting for nose down pitching ( my > incidence was at -.9 degrees). > > By moving weights forward and aft in the same flight, forward CG > was better for maximizing speed - unlike some aircraft that see max speed > when the CG is at the neutral point, probably a consequence of more > standard wing/tail design that saw drag from wing/horizontal +/- lift > factors more balanced and minimized. > > For me, the biggest gain in speed came from adding $140 worth of gap seals > to both sides of all control surface and the flaps (remember Greenameyer > made his flaps part of the wing in his very fast Reno Legacy - he didn't > need no stink'n flaps). I believe that I lost no speed when I removed the > upper seals from the flaps last year. The seals were curved Mylar seals > often obtainable for gliders. The gain was from 6 to 8 KIAS, depending. > Controls were more responsive and the wee rudder was effective about 5 KIAS > sooner. > > I didn't follow up on a cockpit controlled diffuser for managing cooing > drag as I saw about 7" H2O upper to lower cowl at about 135 KIAS (climb > speed), but 13" at 200 KIAS and such pressure was not necessary as the > engine ran cool there. > > I found the small tail had enough control - I only wanted my little engine > to pull everything along as quickly as possible. > > Scott Krueger > > In a message dated 9/13/2013 7:32:54 A.M. Central Daylight Time, > chris_zavatson@yahoo.com writes: > > N91CZ has been a flying laboratory for most of this year. Below are > links to three reports that may be of interest to the Lancair community, in > particular 320/360 flyers. > > The first takes a look at the effect flap position has on total > aircraft drag using the NLF(1)-0215. The numbers are quite impressive in > terms of drag coefficients. In the end, it looks like we could benefit > from a little more reflex beyond -7 degrees. > http://n91cz.com/Performance/Cruise_Flap_Report.pdf > > The second report looks at the neutral point differences and static > margins of the small and large tail 320/360 models. A large portion of the > document is a tutorial of sorts on longitudinal stability. It deals only > with static stability, but is a good lead-in to the third report. > http://n91cz.com/Stability/Lancair360_Static_Stability.pdf > > The third report looks at the stability of the 360 MKII in much greater > detail. It include dynamic stability in both cruise and landing > configurations, as well as, stick force gradients and elevator > effectiveness all the way down to stall speed. > http://n91cz.com/Stability/Lancair360_Stability_and_Control_Evaluation.pdf > > > Chris Zavatson > N91CZ > 360std > http://www.n91cz.net/ > > > -- > For archives and unsub > http://mail.lancaironline.net:81/lists/lml/List.html > > --047d7b6735f0af30f104e69ade34 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
Scott,

Are you able to provide a suppli= er for the material used for the gap seals? Any notes about the installatio= n? An engineer from Lo Presti came across my airplane on the ramp one day a= t a fuel stop and was crawling over it. "Boy, not much left to do on t= his thing!" =A0The only thing he mentioned was extending the ram air i= nlet to be much closer to the prop to maximize efficiency and the installat= ion of gap seals.

I do enough long trips that 6-8kias would be of interes= t to me, especially since I recently managed to hit headwinds over the cour= se of 3 days of flying, even though I flew in all directions in those 3 deg= s (nuts, right?) Every day brought a new and exciting headwind. 'Doh!

Keith


On Sun, Sep 15, 2013 at 3:26 PM, <Sky2high@aol.com= > wrote:
Chris,
=A0
Great research.
=A0
In my small tailed 320, increased flap reflex experimentation=A0did no= t=20 result in increased top end speed.=A0 The nose=A0up pitch was increased,=20 requiring increased nose down trim - probably=A0resulting in greater=20 empennage drag negating any reduction in drag from the=20 greater=A0reflex.=A0 Of course, we would have to discuss the angle of=20 incidence of the small tail and its relationship to the elevator correcting= for=20 nose down pitching ( my incidence was at -.9 degrees).
=A0
By moving weights forward and aft in the same flight, forward CG=20 was=A0better for maximizing speed - unlike some aircraft that see max speed= =20 when the CG is at the neutral point, probably a consequence of more standar= d=20 wing/tail design that saw drag from wing/horizontal +/- lift factors more= =20 balanced and minimized.
=A0
For me, the biggest gain in speed came from adding $140 worth of=A0gap= =20 seals to both sides of=A0all control surface and the flaps=20 (remember=A0Greenameyer made his flaps part of the wing in his very fast Re= no=20 Legacy - he didn't need no stink'n flaps).=A0 I believe that I lost= no speed=20 when I removed the upper seals from the flaps last year.=A0The seals were= =20 curved=A0Mylar seals often obtainable for gliders.=A0 The gain was from 6= =20 to 8 KIAS, depending.=A0 Controls were more responsive and the=20 wee=A0rudder was effective about=A05 KIAS sooner.
=A0
I didn't follow up on a cockpit controlled diffuser for managing c= ooing=20 drag as I saw about 7" H2O upper to lower cowl=A0at about 135 KIAS (cl= imb=20 speed), but 13" at 200 KIAS and such pressure was not necessary as the= engine=20 ran cool there.
=A0
I found the small tail had enough control - I only wanted my little en= gine=20 to pull everything along as quickly as possible.
=A0
Scott Krueger
=A0
In a message dated 9/13/2013 7:32:54 A.M. Central Daylight Time,=20 chris_zavatso= n@yahoo.com writes:
N91CZ has been a flying laboratory for most of this year.=A0 Below a= re=20 links to three reports that may be of interest to the Lancair community, = in=20 particular 320/360 flyers.
=A0
The first takes a look at the effect=A0flap position=A0has on total= =20 aircraft=A0drag using the NLF(1)-0215.=A0=A0The numbers are quite=20 impressive in terms of drag coefficients.=A0=A0In the end, it looks like= =20 we=A0could benefit from a little more reflex beyond -7 degrees.
=A0
The second report looks at the neutral point differences and static= =20 margins of the small and large tail 320/360 models.=A0 A large portion of= =20 the document is a tutorial of sorts on longitudinal stability.=A0 It deal= s=20 only with static stability, but is a good lead-in to the=A0third=20 report.
=A0
The third report looks at the stability of the 360 MKII in much grea= ter=20 detail.=A0 It include dynamic stability in both cruise and landing=20 configurations, as well as, stick force gradients and elevator effectiven= ess=20 all the way down to stall speed.
=A0
=A0
Chris Zavatson
N91CZ
360std



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