X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 13 Jan 2013 17:51:42 -0500 Message-ID: X-Original-Return-Path: Received: from imr-db02.mx.aol.com ([205.188.91.96] verified) by logan.com (CommuniGate Pro SMTP 6.0.1) with ESMTP id 6009896 for lml@lancaironline.net; Sun, 13 Jan 2013 08:51:58 -0500 Received-SPF: pass receiver=logan.com; client-ip=205.188.91.96; envelope-from=Sky2high@aol.com Received: from mtaomg-db03.r1000.mx.aol.com (mtaomg-db03.r1000.mx.aol.com [172.29.51.201]) by imr-db02.mx.aol.com (Outbound Mail Relay) with ESMTP id C31461C000122 for ; Sun, 13 Jan 2013 08:51:23 -0500 (EST) Received: from core-mte003b.r1000.mail.aol.com (core-mte003.r1000.mail.aol.com [172.29.236.73]) by mtaomg-db03.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 951B7E000087 for ; Sun, 13 Jan 2013 08:51:23 -0500 (EST) From: Sky2high@aol.com Full-name: Sky2high X-Original-Message-ID: <12894.3932d36c.3e2415da@aol.com> X-Original-Date: Sun, 13 Jan 2013 08:51:23 -0500 (EST) Subject: Efficiency of Lawn Darts --- and such X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_12894.3932d36c.3e2415da_boundary" X-Mailer: AOL 9.6 sub 168 X-Originating-IP: [67.175.156.123] x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:479792000:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d33c950f2bbdb7d1e --part1_12894.3932d36c.3e2415da_boundary Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en Bill, =20 I was just pulling your main gear leg. However, consider this: =20 Reflexed flap wings have a significant pitching moment. Note their use in= =20 tailless airplanes where the "flap" completely controls the pitch. =20 Referring to only 200/300 Lancairs and specifically the 300 series, the fla= p in =20 reflex creates so much nose up pitch that the elevator is trimmed to unloa= d=20 its negative lift as speed increases. As that negative lift is reduced, s= o=20 is induced drag reduced - thus the aircraft becomes more efficient. If=20 one looks at the horizontal as an upside down wing, one might even say tha= t=20 thru a certain range of the elevator unloading the tail puts the elevator = in=20 reflex. =20 At high speeds, the AOA of the main wing is siginificantly reduced to =20 maintain the same lift (unload the tail) and the reflexed flap may allow t= he=20 laminar flow to re-attach at the flap, further reducing drag.=20 =20 Also, consider also that most canard pushers with air cooled aircraft=20 engines use updraft cooling that is inherently inefficient as the cooling = air=20 passes over the exhaust pipes first (picking up heat) and that its return = to=20 the slip stream suffers from the drag induced by the aft openings of=20 pushers. =20 Scott AKA Grayhawk =20 =20 In a message dated 1/13/2013 1:29:22 A.M. Central Standard Time, =20 super_chipmunk@roadrunner.com writes: =20 Hi Scott- I was exaggerating for effect- However, my understanding is= =20 that canards are theoretically more efficient because the canard provides = a=20 lift component as opposed to a horizontal stabilizer that has to create=20 negative lift. In both cases the aircraft is balanced so the nose drops=20 during a stall. In practice, the canard *has* to stall before the main win= g. The=20 =E2=80=9Cdeep stall=E2=80=9D experienced during a flight test on the Veloc= ity is a case=20 in point. That plane entered a stable vertical descent- I think it was 500= =20 FPM- and couldn=E2=80=99t be gotten out of it. The pilot actually opened t= he door=20 and tried to shift CG by leaning forward. Fortunately it landed in water a= nd=20 the pilot survived with back injuries. The factory did some innovative=20 testing to try to understand what happened. =20 I had one of the first Velocity kits (a very early RG), and after some= =20 time we received cuffs that we were told to put on the elevator LE. I wasn= =E2=80=99t=20 thrilled- I already had everything built and carefully adjusted. I never= =20 heard an explanation, just that it was to adjust the gap and decrease the= =20 lift of the canard. From this, I=E2=80=99d speculate that during the incide= nt the =20 main wing partially stalled while the canard kept flying. Under those ci rcumstances the nose couldn=E2=80=99t drop and the wing couldn=E2=80=99t re= gain lift. So the fix=20 was a compromise that reduced efficiency in return for an extra margin of = =20 safety. =20 I never finished mine as I saw enough fatalities over the years and found = =20 too many construction aspects that I didn=E2=80=99t like. In the end I deci= ded the =20 plane was too limited in terms of fuel capacity and payload so I abandoned= =20 it. My understanding is that as a stall approaches the canard stalls first= =20 due to higher loading, dropping the nose and regaining airspeed. If the=20 conditions continued, the process would repeat. -Bill Wade =20 =20 =20 From: _Sky2high@aol.com_ (mailto:Sky2high@aol.com) =20 Sent: Saturday, January 12, 2013 4:36 PM To: _lml@lancaironline.net_ (mailto:lml@lancaironline.net) =20 Subject: [LML] Re: Fw: [LML] Re: Purchase Advice LNC2 =20 =20 Bill, =20 Recently there have been many canards on this list - Oh, maybe you meant = =20 aircraft with canards. I challenge your statement that they are more =20 efficient. However, they do operate well in the ETE as long as the canard= =20 remains clean as a smutty canard causes loss of lift on that crucial =20 wingy-thingy. Only Klaus has an efficient canard aircraft although you ma= y have to=20 find out how much power he wrings out his engine and what that funny skinn= y=20 prop is doing. BTW, they are good airplanes that avoid main wing stalls a= nd=20 just mush on down. =20 Grayhawk =20 =20 In a message dated 1/12/2013 12:18:16 P.M. Central Standard Time, =20 super_chipmunk@roadrunner.com writes: =20 In this discussion I=E2=80=99m surprised that Canards haven=E2=80=99t been = mentioned. It=E2=80=99 s well known they=E2=80=99re more efficient- surely that=E2=80=99s due to t= he fact that=20 they were designed from the ground up to fly backwards. =20 Also, given the fact that there=E2=80=99s a reversal of the Coriolis eff= ect=20 between the two hemispheres why hasn=E2=80=99t there been a discussion of = ETE-=20 Equitorial Transition Effect? That=E2=80=99s the warping of the space/time = continuum as you=20 approach the Equator and then experience the reversal during passage. This= =20 is distinct from ETA- Everyone=E2=80=99s Talking Australian, a spatial and= =20 temporal dissonance caused by situations such as: =20 What=E2=80=99s a Goanna- is that what=E2=80=99s eating my Marmite (a cute, = fuzzy =20 marsupial). =20 Is it polite to play your Didgeridoo in public or it only for consenting= =20 adults?=20 =20 You get the idea... Cheers- Bill Wade =20 =20 --part1_12894.3932d36c.3e2415da_boundary Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en
Bill,
 
I was just pulling your main gear leg.  However, consider this:
 
Reflexed flap wings have a significant pitching moment.  Note the= ir=20 use in tailless airplanes where the "flap" completely controls the pitch.&n= bsp;=20 Referring to only 200/300 Lancairs and specifically the 300 series, the fla= p in=20 reflex creates so much nose up pitch that the elevator is trimmed to= =20 unload its negative lift as speed increases.  As that negative=20 lift is reduced, so is induced drag reduced - thus the aircraft= =20 becomes more efficient.  If one looks at the horizontal as an upside d= own=20 wing, one might even say that thru a certain range of the elevato= r=20 unloading the tail puts the elevator in reflex.
 
At high speeds, the AOA of the main wing is siginificantly reduce= d to=20 maintain the same lift (unload the tail) and the reflexed flap may all= ow=20 the laminar flow to re-attach at the flap, further reducing drag. 
 
Also, consider also that most canard pushers with air=20 cooled aircraft engines use updraft cooling that is inherently=20 inefficient as the cooling air passes over the exhaust pipes first (picking= up=20 heat) and that its return to the slip stream suffers from the dra= g=20 induced by the aft openings of pushers.
 
Scott AKA Grayhawk
 
In a message dated 1/13/2013 1:29:22 A.M. Central Standard Time,=20 super_chipmunk@roadrunner.com writes:
=
Hi Scott-
           &n= bsp; =20 I was exaggerating for effect- However, my understanding is that canards = are=20 theoretically more efficient because the canard provides a lift component= as=20 opposed to a horizontal stabilizer that has to create negative lift. In b= oth=20 cases the aircraft is balanced so the nose drops during a stall. In pract= ice,=20 the canard *has* to stall before the main wing. The =E2=80=9Cdeep stall= =E2=80=9D experienced=20 during a flight test on the Velocity is a case in point. That plane enter= ed a=20 stable vertical descent- I think it was 500 FPM- and couldn=E2=80=99t be = gotten out of=20 it. The pilot actually opened the door and tried to shift CG by leaning= =20 forward. Fortunately it landed in water and the pilot survived with back= =20 injuries. The factory did some innovative testing to try to understand wh= at=20 happened.
 
  I had one of the first Velocity kits (a very early RG), and a= fter=20 some time we received cuffs that we were told to put on the elevator LE. = I=20 wasn=E2=80=99t thrilled- I already had everything built and carefully adj= usted. I=20 never heard an explanation, just that it was to adjust the gap and decrea= se=20 the lift of the canard. From this, I=E2=80=99d speculate that during the = incident the=20 main wing partially stalled while the canard kept flying. Under those=20 circumstances the nose couldn=E2=80=99t drop and the wing couldn=E2=80=99= t regain lift. So the=20 fix was a compromise that reduced efficiency in return for an extra margi= n of=20 safety.
 
I never finished mine as I saw enough fatalities over the years and = found=20 too many construction aspects that I didn=E2=80=99t like. In the end I de= cided the=20 plane was too limited in terms of fuel capacity and payload so I abandone= d it.=20 My understanding is that as a stall approaches the canard stalls first du= e to=20 higher loading, dropping the nose and regaining airspeed. If the conditio= ns=20 continued, the process would repeat.  -Bill Wade
=
Sent: Saturday, January 12, 2013 4:36 PM
Subject: [LML] Re: Fw: [LML] Re: Purchase Advice=20 LNC2
 
=
Bill,
 
Recently there have been many canards on this list - Oh, maybe you m= eant=20 aircraft with canards.  I challenge your statement that they are mor= e=20 efficient.  However, they do operate well in the ETE as long as the= =20 canard remains clean as a smutty canard causes loss of lift on that cruci= al=20 wingy-thingy.  Only Klaus has an efficient canard aircraft although = you=20 may have to find out how much power he wrings out his engine and what tha= t=20 funny skinny prop is doing.  BTW, they are good airplanes that avoid= main=20 wing stalls and just mush on down.
 
Grayhawk
 
In a message dated 1/12/2013 12:18:16 P.M. Central Standard Time,=20 super_chipmunk@roadrunner.com writes:
  In this discussion I=E2=80=99m surprised that Canards haven= =E2=80=99t been=20 mentioned. It=E2=80=99s well known they=E2=80=99re more efficient- sure= ly that=E2=80=99s due to the=20 fact that they were designed from the ground up to fly backwards.
 
  Also, given the fact that there=E2=80=99s a reversal of the= Coriolis=20 effect between the two hemispheres why hasn=E2=80=99t there been a disc= ussion of=20 ETE- Equitorial Transition Effect? That=E2=80=99s the warping of the sp= ace/time=20 continuum as you approach the Equator and then experience the reversal= =20 during passage. This is distinct from ETA- Everyone=E2=80=99s Talking A= ustralian, a=20 spatial and temporal dissonance caused by situations such as:
 
What=E2=80=99s a Goanna- is that what=E2=80=99s eating my Marmite = (a cute, fuzzy=20 marsupial).
 
Is it polite to play your Didgeridoo in public or it only for=20 consenting adults?
 
You get the idea...  Cheers- Bill Wade
 
 
=
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