Return-Path: Received: from [24.25.9.100] (HELO ms-smtp-01-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.2b2) with ESMTP id 3204488 for flyrotary@lancaironline.net; Mon, 03 May 2004 21:11:20 -0400 Received: from EDWARD (clt25-78-058.carolina.rr.com [24.25.78.58]) by ms-smtp-01-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id i441BHSn020288 for ; Mon, 3 May 2004 21:11:18 -0400 (EDT) Message-ID: <001701c43174$b416b190$2402a8c0@EDWARD> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Tail Wing Incident Date: Mon, 3 May 2004 21:11:17 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0014_01C43153.2CCBD920" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1409 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0014_01C43153.2CCBD920 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable ----- Original Message -----=20 From: Dean=20 To: Rotary motors in aircraft=20 Sent: Monday, May 03, 2004 3:43 PM Subject: [FlyRotary] Re: Tail Wing Incident ----- Original Message -----=20 From: Ed Anderson=20 To: Rotary motors in aircraft=20 Sent: Monday, May 03, 2004 2:10 PM Subject: [FlyRotary] Tail Wing Incident -----=20 From: Tracy Crook=20 To: Rotary motors in aircraft=20 Sent: Monday, May 03, 2004 2:42 PM Subject: [FlyRotary] Re: Injector testing I probably am overpropped at static and low speed. I told Clark = Lydick to build me a speed prop. I figured that being overpropped on = take-off doesnt matter if you have lots of HP and can get off the ground = in 1200 ft and climb like a banshee anyway. I'll be sending the prop = back for adjustment once I get solid numbers, but I don't think I'll = want him to cut it back much. john Slade=20 What sort of top speed, and cruise speed do you expect? What = would be common for an O-360 powered plane?=20 Cheers, Rusty (wishing the RV airfoil wasn't so draggy over 220 mph) I used to think the same thing (draggy airfoil) but I think the = problem with RVs over 220 is related to wing / tail / fuselage = incidence. At 220 I get the visual impression that I am in a dive = during level flight. The early Citation jets used the same airfoil as the lowly RV. Tracy Tracy,=20 As you known, the airflow over the horizontal tail is such as = to exert down force on the tail (Nose up) to overcome the forward = pitching movement of the CL of the wing airfoil. I suspect that at the = higher airspeeds the airflow over the wing could be changed sufficiently = that the tail surface might be providing less downforce (nose up ) than = required. In otherwords the downforce on the horizontal stab is = sufficiently lessened that the nose lowers until the horizontal stab = finds a new equilibrium point at your higher airspeed. As nose goes = down, more of the upper surface of the horiz stab is exposed to the = airflow causing more down force/nose up until the new equilibrium is = reached. Just a thought. Ed Ed Not questioning anything you just stated. Keep in mind also, = that with the dynamic pressure increasing as the square of the speed, = the required angle of attack of the wing is reduced and the nose goes = down from that alone. I am not sure what the CL shift is as the AOA = decreases with increase in speed. Tracy is seeing AS numbers that I = will never see on my 9A. Dean Van Winkle RV-9A 13B Good point, Dean. Also I would presume the CL position on the = wing could be affected by airspeed anc could may be a factor as well - = its all magic in any case {:>). I am certain I also will never see such = speeds in my 6A (at least not intentionally), but I sure do want to = taste some of that take off roll acceleration and climb that Tracy has = reported. Ed Ed Anderson RV-6A N494BW Rotary Powered Matthews, NC ------=_NextPart_000_0014_01C43153.2CCBD920 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
----- Original Message -----
From:=20 Dean=20
Sent: Monday, May 03, 2004 3:43 = PM
Subject: [FlyRotary] Re: Tail = Wing=20 Incident

 
----- Original Message -----
From:=20 Ed Anderson
To: Rotary motors in = aircraft=20
Sent: Monday, May 03, 2004 = 2:10=20 PM
Subject: [FlyRotary] Tail = Wing=20 Incident

-----
From:=20 Tracy = Crook=20
To: Rotary motors in = aircraft=20
Sent: Monday, May 03, 2004 = 2:42=20 PM
Subject: [FlyRotary] Re: = Injector=20 testing

 
I = probably am=20 overpropped at static and low speed.  I told Clark Lydick = to build=20 me a speed prop. I figured that being overpropped on take-off = doesnt=20 matter if you have lots of HP and can get off the ground in 1200 = ft and=20 climb like a banshee anyway. I'll be sending the prop back for=20 adjustment once I get solid numbers, but I don't think I'll want = him to=20 cut it back much.
john Slade 
 
What sort of top = speed, and cruise=20 speed do you expect?  What would be common = for an=20 O-360 powered=20 = plane? 
 
Cheers,
Rusty (wishing the RV = airfoil=20 wasn't so draggy over 220=20 mph)
 
I used to think the = same thing=20 (draggy airfoil)  but I think the problem with RVs over 220 = is=20 related to wing / tail / fuselage incidence.   At = 220=20 I get the visual impression that I am in a dive during = level=20 flight.
&nbs= p;
The early Citation = jets used the=20 same airfoil as the lowly=20 RV.
&nbs= p;
Tracy
&nbs= p;
Tracy,=20
&nbs= p;
   As you = known, the=20 airflow over the horizontal tail is such as to exert down force = on the=20 tail (Nose up) to overcome the forward pitching movement of the = CL of=20 the wing airfoil.  I suspect that at the higher airspeeds = the=20 airflow over the wing could be changed sufficiently that the = tail=20 surface might be providing less downforce (nose up ) than=20 required.    In otherwords the downforce on the=20 horizontal stab  is sufficiently lessened that the nose = lowers=20 until the horizontal stab finds a new equilibrium point at your = higher=20 airspeed.  As nose goes down, more of the upper surface of = the=20 horiz stab is exposed to the airflow causing more down = force/nose up=20 until the new equilibrium is reached.  Just a=20 thought.
&nbs= p;
&nbs= p;
&nbs= p;
Ed
 
Ed
 
Not questioning anything you = just=20 stated.  Keep in mind also, that with the dynamic pressure=20 increasing as the square of the speed, the required angle of = attack of=20 the wing is reduced and the nose goes down from that = alone.  I am=20 not sure what the CL shift is as the AOA decreases with increase = in=20 speed.  Tracy is seeing AS numbers that I will never see on = my=20 9A.
 
Dean Van = Winkle   =20 RV-9A   13B
 
Good point, Dean.  Also I = would=20 presume the CL position on the wing could be affected by = airspeed anc=20 could may be a factor as well - its all magic in any case = {:>). =20 I am certain I also will never see such speeds in my 6A (at = least not=20 intentionally), but I sure do want to taste some of that take = off roll=20 acceleration and climb that Tracy has reported.
 
Ed
 
 
Ed Anderson
RV-6A N494BW Rotary=20 Powered
Matthews,=20 = NC
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