X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 17 Apr 2012 16:54:35 -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 5.4.4) with ESMTP id 5485148 for lml@lancaironline.net; Tue, 17 Apr 2012 10:15:20 -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=2.0 cv=V/z/IJbi c=1 sm=0 a=MHZY6FYWMEQOp7S43i2QIw==:17 a=3Zlka_XeuxsA:10 a=ttCsPuSJ-FAA:10 a=3oc9M9_CAAAA:8 a=Ia-xEzejAAAA:8 a=rTjvlri0AAAA:8 a=Z9wnGblNPIlTmfKfLSwA:9 a=5wvVOxtn6w77Njmy-rMA:7 a=QEXdDO2ut3YA:10 a=CVU0O5Kb7MsA:10 a=U8Ie8EnqySEA:10 a=EzXvWhQp4_cA:10 a=Dr9Wx-Q63l4A:10 a=fv50BRHzAAAA:8 a=Ah5MGYbmj9C0CU65FSQA:9 a=rwYpClnm-tw5gqtXzFIA:7 a=ORsapS7FR98A:10 a=MHZY6FYWMEQOp7S43i2QIw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.218.201.50 Received: from [74.218.201.50] ([74.218.201.50:1551] helo=lobo) by hrndva-oedge04.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id C7/4C-13145-4DA7D8F4; Tue, 17 Apr 2012 14:14:44 +0000 X-Original-Message-ID: <005301cd1ca4$6f2d33a0$6701a8c0@lobo> From: "Wolfgang" X-Original-To: References: Subject: Re: [LML] Fw: L320 flap setting X-Original-Date: Tue, 17 Apr 2012 10:14:42 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0050_01CD1C82.E7D67450" 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_0050_01CD1C82.E7D67450 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable I have a tendency to give NASA reports more credibility . . . even if = they do not reflect EXACTLY some other implementation.=20 Adding flaps is little different from adding camber to a symmetrical = wing. It does increase the coefficient of lift . . . as much as a factor = of two in some cases. . . . and when the added camber (too much flap) creates more turbulence = than redirected air flow, you get more drag vs. more lift . . . usually = some measure of both. That's what sloted flaps are all about, to minimize the added drag when = extended. But keep in mind that even if you do get a 2 times coefficient of lift = with flaps, your air speed can only be reduced to 0.7 (lift is = proportional to the square of speed) Ref: Theory of Wing Sections gives good detail on many wing shapes and = the effect of flaps and pitching moments. Wolfgang ----- Original Message -----=20 From: Sky2high@aol.com=20 To: lml@lancaironline.net=20 Sent: Monday, April 16, 2012 8:55 PM Subject: Re: [LML] Fw: L320 flap setting Wolfgang, Regardless of what the NASA report says, they never flew the wing as = implemented by Lancair. Extension of the flap more than a few degrees = beyond 0 does little for lift. The pitching moment does change the = attitude, but does not significantly change the stall speed (a few knots = is not significant). The drag addition is significant. The AOA is = another story. While the attitude changes with flap extension, the AOA = is still high and slower speeds just brings one closer to a stall, thus = reducing margins to take care of loss of pilot attention, wind shear, = distractions and anything that leads to mis-application of up elevator = with pitch sensitive controls. It is very easy to reach critical AOA at = slow speeds, with or without flaps.............. Scott Krueger=20 In a message dated 4/16/2012 7:20:08 A.M. Central Daylight Time, = Wolfgang@MiCom.net writes: -7 to -10 isn't going to make much difference in flight. If the = latest manual says to use -7 then go for it. The purpose of reflex flaps is to reduce drag (lets you go faster) = while giving up some lift coefficient. At higher speeds you don't need = that extra lift coefficient. Reflex will also move the center of lift forward causing a nose up = force affecting the trim needs. For landing, you give extra flap to increase the lift coefficient = (and the drag) so you can go slower without falling out of the sky. See attached file for more details. Wolfgang ----- Original Message -----=20 From: Ed Gray=20 To: lml@lancaironline.net=20 Sent: Saturday, April 14, 2012 12:01 AM Subject: L320 flap setting I have the exact concerns reported by Rob Stevens in Australia. = Since the manual is vague on cruise flap settings, can some experienced = L320-360 fliers help us with what is the best cruise settings? Is it = -7deg. , -10deg., or somewhere else. Since construction variances can = create different =E2=80=9Cfaired-in positions=E2=80=9D, is there an = angle which can be measured from the top or bottom wing surface? Can = anyone explain the aerodynamic reasons for reflexed flaps? Rob and I = need help! Ed Gray Dallas L360 N77ZG XP360 Silver Hawk injection MT 3 blade = prop Dual Dynon Skyview SL30 -- For archives and unsub = http://mail.lancaironline.net:81/lists/lml/List.html ------=_NextPart_000_0050_01CD1C82.E7D67450 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable =EF=BB=BF
I have a tendency to give NASA reports more credibility . . . = even if=20 they do not reflect EXACTLY some other implementation.
 
Adding flaps is little different from adding camber to a = symmetrical wing.=20 It does increase the coefficient of lift . . . as much as a factor of = two in=20 some cases.
. . . and when the added camber (too much flap) creates more = turbulence=20 than redirected air flow, you get more drag vs. more lift . . . usually = some=20 measure of both.
That's what sloted flaps are all about, to minimize the added=20 drag when extended.
But keep in mind that even if you do get a 2 times coefficient of = lift with=20 flaps, your air speed can only be reduced to 0.7 (lift is = proportional to=20 the square of speed)
 
Ref: Theory of Wing Sections gives good detail on many wing shapes = and the=20 effect of flaps and pitching moments.
 
Wolfgang
 
----- Original Message -----
From:=20 Sky2high@aol.com=20
Sent: Monday, April 16, 2012 = 8:55=20 PM
Subject: Re: [LML] Fw: L320 = flap=20 setting

Wolfgang,
 
Regardless of what the NASA report says, they never flew the wing = as=20 implemented by Lancair.  Extension of the flap more than a few = degrees=20 beyond 0 does little for lift.  The pitching moment does change = the=20 attitude, but does not significantly change the stall speed (a few = knots is=20 not significant).  The drag addition is significant.  The = AOA is=20 another story.  While the attitude changes with flap extension, = the AOA=20 is still high and slower speeds just brings one closer to a stall, = thus=20 reducing margins to take care of loss of pilot attention, wind shear,=20 distractions and anything that leads to mis-application of up = elevator=20 with pitch sensitive controls.  It is very easy to reach critical = AOA at=20 slow speeds, with or without flaps..............
 
Scott Krueger 
 
In a message dated 4/16/2012 7:20:08 A.M. Central Daylight Time,=20 Wolfgang@MiCom.net writes:
-7 to -10 isn't going to make much = difference=20 in flight. If the latest manual says to use -7 then go for = it.
 
The purpose of reflex flaps is to = reduce drag=20 (lets you go faster) while giving up some lift coefficient. At = higher speeds=20 you don't need that extra lift coefficient.
Reflex will also move the center of = lift=20 forward causing a nose up force affecting the trim = needs.
 
For landing, you give extra flap to = increase=20 the lift coefficient (and the drag) so you can go slower without = falling out=20 of the sky.
 
See attached file for more=20 details.
 
Wolfgang
 
 
----- Original Message -----=20
From: = Ed=20 Gray
Sent: Saturday, April 14, 2012 12:01 AM
Subject: L320 flap setting

I have the = exact concerns=20 reported by Rob Stevens in Australia.  Since the manual is = vague on=20 cruise flap settings, can some experienced L320-360 fliers help us = with what=20 is the best cruise settings?  Is it -7deg. , -10deg., or = somewhere=20 else.  Since construction variances can create different = =E2=80=9Cfaired-in=20 positions=E2=80=9D, is there an angle which can be measured from the = top or bottom=20 wing surface?  Can anyone explain the aerodynamic reasons for = reflexed=20 flaps?  Rob and I need help!

Ed Gray = Dallas  L360=20 N77ZG XP360 Silver Hawk injection MT 3 blade prop Dual Dynon Skyview = SL30



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For archives and unsub = = http://mail.lancaironline.net:81/lists/lml/List.html
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