X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 10 Aug 2010 16:52:05 -0400 Message-ID: X-Original-Return-Path: Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122] verified) by logan.com (CommuniGate Pro SMTP 5.3.8) with ESMTP id 4425115 for lml@lancaironline.net; Tue, 10 Aug 2010 10:16:17 -0400 Received-SPF: none receiver=logan.com; client-ip=71.74.56.122; envelope-from=Wolfgang@MiCom.net X-Original-Return-Path: X-Authority-Analysis: v=1.1 cv=AJ94V2XR2S5W0hXP0aXjlXmhDthNVQT+U2PHnzCS19E= c=1 sm=0 a=MHZY6FYWMEQOp7S43i2QIw==:17 a=Ia-xEzejAAAA:8 a=ndVRne3UAAAA:8 a=rTjvlri0AAAA:8 a=3oc9M9_CAAAA:8 a=oGKzUJ4yAAAA:8 a=CjxXgO3LAAAA:8 a=jYEpPFYi-rRu0eBccS4A:9 a=EQEuxhbWk0o4llDeR8VWnswiKKQA:4 a=wPNLvfGTeEIA:10 a=fzsbTR6MAPIA:10 a=ILeVjEvywfEA:10 a=EzXvWhQp4_cA:10 a=Dr9Wx-Q63l4A:10 a=U8Ie8EnqySEA:10 a=rC2wZJ5BpNYA:10 a=WGVFgrR7L8vRiUDAF48A:9 a=bfSqJWwdr1kEUt6nJZ0A:7 a=5j4WHUbW5ooHdfBUvJyBz1agJUYA:4 a=MHZY6FYWMEQOp7S43i2QIw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.218.201.50 Received: from [74.218.201.50] ([74.218.201.50:1207] helo=Lobo) by hrndva-oedge01.mail.rr.com (envelope-from ) (ecelerity 2.2.2.39 r()) with ESMTP id 28/5D-24722-D0F516C4; Tue, 10 Aug 2010 14:15:41 +0000 X-Original-Message-ID: <00a601cb3896$7bd13870$6401a8c0@Lobo> From: "Wolfgang" X-Original-To: References: Subject: Re: [LML] Re: flap coupling X-Original-Date: Tue, 10 Aug 2010 10:15:28 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00A3_01CB3874.F48D64E0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 This is a multi-part message in MIME format. ------=_NextPart_000_00A3_01CB3874.F48D64E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable The drag bucket moves as the flaps are repositioned. That's what I'm = looking to investigate on the 300 series. Are you saying that the MkII tail uses a servo tab for trim ? Wolfgang ----- Original Message -----=20 From: Chris Zavatson=20 To: lml@lancaironline.net=20 Sent: Monday, August 09, 2010 7:33 PM Subject: Re: [LML] Re: flap coupling Wolfgang, The MkII tail uses a servo to drive the trim tab. If installed, the = bob-weight is the only thing contributing to any static force in rear = half of the system. If an autopilot is fighting an out of trim = condition that would add some force-much like the old trim system does. = Outside of that all trim forces for the large tail are self-contained in = the elevator. Attached are some charts showing the benefits of reflex relative to = the 320/360. Chris Zavatson N91CZ 360std www.N91CZ.com -------------------------------------------------------------------------= ----- From: Wolfgang To: lml@lancaironline.net Sent: Mon, August 9, 2010 12:04:51 PM Subject: [LML] Re: flap coupling The push rod forces are definitely there.=20 The trim system that keeps those forces from showing up at the control = stick. . . . . unless you're using servo tabs . . . . Yes, I want to map the drag bucket for various flap conditions.=20 NASA tech paper 1865 shows it's effect. I want to expand that on the = 300 series. I believe it can add some efficiency points if utilized. Wolfgang -------------------------------------------------------------------------= ----- From: Sky2high@aol.com=20 Sender: =20 Subject: Re: [LML] Re: flap coupling=20 Date: Mon, 09 Aug 2010 07:33:19 -0400=20 To: lml@lancaironline.net=20 =20 =20 Uh, the push rod forces should be zero when trimmed. If one = cannot reach a trimmed configuration, then force will be required to = reach sustained level flight. One can only wonder about the position of = the trimming device (there are so many different methods) when one then = calculates forces necessary for level flight at different = airspeeds/configurations. Wolfgang is seeking the "drag bucket" for different flight = regimes. The purpose is unknown. Each configuration change affects = either lift (induced drag) or parasitic drag or both. Faster =3D less = induced drag, more parasitic drag. Slower =3D more induced drag, less = parasitic. Parasites are everywhere. = http://www.charlesriverrc.org/articles/asfwpp/lelke_airfoilperf.htm = clarifies the "drag bucket" concept. Good (an extra "o" converts God to = good) Is only of concern at cruise configurations. Why? Because = anything else is confounded by other variables - density altitude, wind, = efficiency, etc. The designer defined the cruise range as the best = conditions (altitude, power, etc) where the longeron was level. Other = things can affect drag, engine cooling, laminar flow because of smooth = surfaces, weight (lift-induced drag), wax (parasitic drag), etc. etc. = etc. =20 Who cares at other speeds less than cruise - we know that max = efficiency can be reached when parasitic drag and induced drag cross at = some minima. Uh, the old max range vs max endurance question. = Frequently, best efficiency occurs at best glide speed (like 107 KIAS in = a half loaded 320). So what? Do I care if I can reach Austin, TX in 8 = hours using only 20 gallons or 4.3 hours using 30 gallons or 4.8 hours = at best power requiring a fuel stop to maintain minimums (43 gal tank). = Of course. But I don't need anything more than ROP/LOP fuel burns and = associated TAS - fortunately for my very slick bird, there is only a = loss of 6 or 7 knots for a drop of 2 gph from ROP to LOP at some useful = altitude. So, I get >1 hour more endurance at LOP and I can see if that = 28 NM difference (4 hours) is worth the 1 hour refueling stop. Uh, = Austin is a flip of the coin at 820 NM (wind and weather depending). Scott Krueger LNC2 320 =20 In a message dated 8/8/2010 6:46:31 P.M. Central Daylight Time, = chris_zavatson@yahoo.com writes: The MKII tail is a little different. Push rod forces are zero = for all trimmed conditions. Chris Zavatson =20 N91CZ =20 360std www.N91CZ.com =20 ---------------------------------------------------------------------- From: Wolfgang To: lml@lancaironline.net Sent: Fri, August 6, 2010 10:06:44 PM Subject: [LML] Re: flap coupling I have taken elevator pushrod force measurements and was = surprised. Elevator pushrod forces to stick forces are about 6.5 to 1 The trim system, when dialed in, provides these forces. At 190 imph and -7=BA flaps, there is a 60lb forward force. At 80 imph and 10=BA flaps, there is about zero force. At 80 imph and 20=BA flaps, there is a slight (-1lb) rearward = force. These numbers are with the horizontal stabilizer built at = -1.2=BA - - - plans range is -0.5=BA to -1.0=BA An input from the flap bellcrank of about 20-40 lb at -7=BA = would be good, tapering down to zero lbs at 10=BA flaps A horizontal stabilizer built at -0.5=BA would, of course, = change these numbers. Comments ? Wolfgang =20 ------=_NextPart_000_00A3_01CB3874.F48D64E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
The drag bucket moves as the flaps are=20 repositioned. That's what I'm looking to investigate on the 300=20 series.
 
Are you saying that the MkII tail uses = a servo tab=20 for trim ?
 
Wolfgang
 
----- Original Message -----
From:=20 Chris=20 Zavatson
Sent: Monday, August 09, 2010 = 7:33=20 PM
Subject: Re: [LML] Re: flap=20 coupling

Wolfgang,
The MkII tail uses a servo to drive the trim tab.  If = installed, the=20 bob-weight is the only thing contributing to any static force in rear = half of=20 the system.  If an autopilot is fighting an out of trim condition = that=20 would add some force-much like the old trim system = does. =20 Outside of that all trim forces for the large tail are self-contained = in the=20 elevator.
Attached are some charts showing the benefits of reflex relative = to the=20 320/360.
 
Chris Zavatson
N91CZ
360std

From: Wolfgang=20 <Wolfgang@MiCom.net>
To: = lml@lancaironline.net
Sent: Mon, August 9, 2010 = 12:04:51=20 PM
Subject: [LML] = Re: flap=20 coupling

The push rod forces are definitely = there.=20
The trim system that keeps those = forces from=20 showing up at the control stick.
. . . . unless you're using servo = tabs . . .=20 .
 
Yes, I want to map the drag bucket = for various=20 flap conditions.
NASA tech paper 1865 shows it's = effect. I want to=20 expand that on the 300 series.
I believe it can add some efficiency = points if=20 utilized.
 
Wolfgang
lml@lancaironline.net
From: Sky2high@aol.com
Sender: <marv@lancaironline.net>
Subject: Re: [LML] Re: flap = coupling
Date: Mon, 09 Aug 2010 07:33:19=20 -0400
To:
Uh, the push rod forces should be zero when trimmed.  = If one=20 cannot reach a trimmed configuration, then force will be = required to=20 reach sustained level flight.  One can only wonder about = the=20 position of the trimming device (there are so many different = methods)=20 when one then calculates forces necessary for level flight = at=20 different airspeeds/configurations.
 
Wolfgang is seeking the "drag bucket" for different flight=20 regimes.  The purpose is unknown.  Each configuration = change=20 affects either lift (induced drag) or parasitic drag or = both. =20 Faster =3D less induced drag, more parasitic drag.  Slower = =3D more=20 induced drag, less parasitic.  Parasites are = everywhere.
 
http://www.charlesriverrc.org/articles/asfwpp/lelke_airfoi= lperf.htm clarifies=20 the "drag bucket" concept.  Good (an extra "o" converts God = to=20 good) Is only of concern at cruise configurations.  = Why? =20 Because anything else is confounded by other variables - density = altitude, wind, efficiency, etc.  The designer defined the = cruise=20 range as the best conditions (altitude, power, etc) where the = longeron=20 was level.  Other things can affect drag, engine cooling, = laminar=20 flow because of smooth surfaces, weight (lift-induced drag), wax = (parasitic drag), etc. etc. etc. 
 
Who cares at other speeds less than cruise - we know = that max=20 efficiency can be reached when parasitic drag and induced drag = cross at=20 some minima.  Uh, the old max range vs max endurance = question.=20   Frequently, best efficiency occurs at best glide speed = (like 107=20 KIAS in a half loaded 320).  So what?  Do I care = if I can=20 reach Austin, TX in 8 hours using only 20 gallons or 4.3 = hours=20 using 30 gallons or 4.8 hours at best power requiring a = fuel stop=20 to maintain minimums (43 gal tank).  Of course.  But I = don't=20 need anything more than ROP/LOP fuel burns and associated TAS -=20 fortunately for my very slick bird, there is only a loss of = 6 or 7=20 knots for a drop of 2 gph from ROP to LOP at some useful=20 altitude.  So, I get >1 hour = more endurance at=20 LOP and I can see if that 28 NM difference (4 hours) is = worth the 1=20 hour refueling stop.  Uh, Austin is a flip of the coin at = 820 NM=20 (wind and weather depending).
 
Scott Krueger
LNC2 320     
 
In a message dated 8/8/2010 6:46:31 P.M. Central Daylight = Time,=20 chris_zavatson@yahoo.com writes:
The MKII tail is a little different.  Push rod = forces=20 are zero for all trimmed conditions.
 
Chris Zavatson   
N91CZ   
360std

 

From: Wolfgang=20 <Wolfgang@MiCom.net>
To:=20 lml@lancaironline.net
Sent: Fri, August = 6, 2010=20 10:06:44 PM
Subject: [LML] Re: flap=20 coupling

I have taken elevator pushrod = force=20 measurements and was surprised.
Elevator pushrod forces to = stick forces=20 are about 6.5 to 1
The trim system, when dialed = in, provides=20 these forces.
 
At 190 imph and -7=BA = flaps, there is=20 a 60lb forward force.
At 80 imph and 10=BA flaps, = there is about=20 zero force.
At 80 imph and 20=BA flaps, = there is a=20 slight (-1lb) rearward force.
 
These numbers are with the = horizontal=20 stabilizer built at -1.2=BA
- - - plans range is -0.5=BA = to=20 -1.0=BA
 
An input from the flap = bellcrank of=20 about 20-40 lb at -7=BA would be good,
 tapering down to zero = lbs at 10=BA=20 flaps
 
A horizontal stabilizer built = at -0.5=BA=20 would, of course, change these numbers.
 
Comments ?
 
Wolfgang
 

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