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Flight Levels magazine - Fall 2008 issue
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barry.collman(at)air-brit
Guest

Posted: Fri Nov 07, 2008 9:08 am Post subject: Flight Levels magazine - Fall 2008 issue

Hi Guys,

  

 On page 7 of the  subject magazine there's a photo of N2621B, a Commander 520 s/n  133.

  

 The text says it's powered by "a pair of geared Lycoming 520-cubic-inch GO-435-C2B  engines".

  

 Has anyone else spotted the (not deliberate)  error?

  

 Best Regards,

 Barry

    [quote][b]

yourtcfg(at)aol.com
Guest

Posted: Fri Nov 07, 2008 5:12 pm Post subject: Flight Levels magazine - Fall 2008 issue

Yep, I saw that too.  Maybe they should have you proof the next ome!!  jb

   	  Quote: 	
		    

   The text says it's powered by "a pair of geared Lycoming 520-cubic-inch GO-435-C2B engines".

 	


 

 

 --

drwer2

Joined: 24 Sep 2008
Posts: 41
Location: Squaw Valley, CA

Posted: Fri Nov 07, 2008 6:56 pm Post subject: Flight Levels magazine - Fall 2008 issue

Well, if "ome" has 520 ci then they would produce 2x380x520/435 = 908 hp.  Wow, I wonder what the GTOW would be!?

  

 I've always been curious about the wing/loading for these AC.  They all have relatively the same wing structure. (longer wingtip for the 680/560's) yet with bigger engines, the FAA allowed higher gross weights.   Was Aero Design able to argue that the original design was (under powered) or over designed?  Which was it and at what HP/gross is the maximum?

  

  

  

 



--- On Fri, 11/7/08, yourtcfg(at)aol.com <yourtcfg(at)aol.com> wrote:



 [quote]From: yourtcfg(at)aol.com <yourtcfg(at)aol.com>

Subject: Re: Flight Levels magazine - Fall 2008 issue

To: commander-list(at)matronics.com

Date: Friday, November 7, 2008, 5:12 PM



 Yep, I saw that too.  Maybe they should have you proof the next ome!!  jb

  	  Quote: 	
		   

 The text says it's powered by "a pair of geared Lycoming 520-cubic-inch GO-435-C2B engines".

	


--

_________________
No Generality is worth a damn....including this one.

cogito ergo aero-geek

yourtcfg(at)aol.com
Guest

Posted: Sat Nov 08, 2008 10:33 am Post subject: Flight Levels magazine - Fall 2008 issue

Over designed I think.  The same airframe wing structure can carry as much as 8500 pounds, thought some Commanders are limited to 6000 gross.  The gross weight is determined by the FAA mandated single engine climb performance.  A model 680 has the same power as a 680E but a 500 pound lower gross.  Some 680s were extended to the "E" wingspan and the gross went up to 7500 pounds.  jb

   	  Quote: 	
		  Which was it and at what HP/gross is the maximum? 	


 

 

 --

drwer2

Joined: 24 Sep 2008
Posts: 41
Location: Squaw Valley, CA

Posted: Sat Nov 08, 2008 1:17 pm Post subject: Flight Levels magazine - Fall 2008 issue

I think so too.

  

 I was a spectator at a few "ultimate" load tests.  One for the A380.  I was told that it took 10x the "rated" load before failing.  They said they were pleased with the results so I guess it made it past FAA and JAR.



--- On Sat, 11/8/08, yourtcfg(at)aol.com <yourtcfg(at)aol.com> wrote:



 [quote]From: yourtcfg(at)aol.com <yourtcfg(at)aol.com>

Subject: Re: Flight Levels magazine - Fall 2008 issue

To: commander-list(at)matronics.com

Date: Saturday, November 8, 2008, 10:33 AM



 Over designed I think.  The same airframe wing structure can carry as much as 8500 pounds, thought some Commanders are limited to 6000 gross.  The gross weight is determined by the FAA mandated single engine climb performance.  A model 680 has the same power as a 680E but a 500 pound lower gross.  Some 680s were extended to the "E" wingspan and the gross went up to 7500 pounds.  jb

  	  Quote: 	
		  Which was it and at what HP/gross is the maximum? 	


--

_________________
No Generality is worth a damn....including this one.

cogito ergo aero-geek

John Vormbaum

Joined: 21 Aug 2006
Posts: 273
Location: SF Bay Area, CA

Posted: Sat Nov 08, 2008 1:33 pm Post subject: Flight Levels magazine - Fall 2008 issue

Jim,



I thought the wing & spar structures were the same on all the 

Commanders. They're not? I know the turbines are easily a 12,000-lb. 

wing, but I've been under the illusion that the wing on my 500B is 

essentially the same thing...



/John



willis robison wrote:

[quote] I think so too.

  

 I was a spectator at a few "ultimate" load tests.  One for the 

 A380.  I was told that it took 10x the "rated" load before failing.  

 They said they were pleased with the results so I guess it made it 

 past FAA and JAR.



 --- On *Sat, 11/8/08, yourtcfg(at)aol.com /<yourtcfg(at)aol.com>/* wrote:



     From: yourtcfg(at)aol.com <yourtcfg(at)aol.com>

     Subject: Re: Flight Levels magazine - Fall 2008 issue

     To: commander-list(at)matronics.com

     Date: Saturday, November 8, 2008, 10:33 AM



     Over designed I think.  The same airframe wing structure can carry

     as much as 8500 pounds, thought some Commanders are limited to

     6000 gross.  The gross weight is determined by the FAA mandated

     single engine climb performance.  A model 680 has the same power

     as a 680E but a 500 pound lower gross.  Some 680s were extended to

     the "E" wingspan and the gross went up to 7500 pounds.  jb



         Which was it and at what HP/gross is the maximum?





     --

drwer2

Joined: 24 Sep 2008
Posts: 41
Location: Squaw Valley, CA

Posted: Sat Nov 08, 2008 5:07 pm Post subject: Flight Levels magazine - Fall 2008 issue

Gents,

 

The following was gleaned from the production data on the commander website and from the NACA archives.

 

There appears to be two variants of the commander wing; a  44’ and a 49’  Both variants use the NACA 23012 airfoil from root to tip.   This particular airfoil is know for its docile behavior and was widely used by other aircraft.  Most notably the Beech Staggerwing uses this airfoil as do other Beech Aircraft, but only in the outboard sections near the ailerons.  The Commanders use a single airfoil from root to tip.  This was chosen likely for its ease of manufacture.  From a manufacturing standpoint, adding 5’ to the wingspan is easier to do by either lengthening the tips outboard of the ailerons or increasing the engine/nacelle truss section. This could mean adding just one or two rib sections

 

The 49’ wing is the archetype and is featured on all the piston twin commanders except the so-called “straight” 560 and 680 models.  The 560 was produced from 1954 to 1957 and the 680 ran from ’55 to ’58.

 

There is also a notable difference in the fuel capacity for the 44’ 560 which has 145 gals compared to the 500s which have 156 gallons normally.  All the Long range models of 560E, F and 680F, L,P have 223 gallons  apparently using all the available bays inboard of the ailerons. 

 

As for weight. It looks like the early models (round nacelle) had usefull loads around 2100 lbs with variations trading up or down depending on HP and Service ceiling.  Twin Commander corporation has mentioned that they don’t have model years, per-se; so this has allowed them to make production runs of a particular type using the same production space.

 

When the Streamlined Nacell was introduced, there was also a notable increase in useful load. To about 2300  to 3200 lbs.  This also improved their service ceiling from an average of 22 kft. To 28kft in the E and F models

_________________
No Generality is worth a damn....including this one.

cogito ergo aero-geek

craigk391(at)sbcglobal.ne
Guest

Posted: Sat Nov 08, 2008 5:17 pm Post subject: Flight Levels magazine - Fall 2008 issue

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> My money is on the 560F

Sent via BlackBerry by AT&T

From:  willis robison <drwer2(at)yahoo.com>

Date: Sat, 8 Nov 2008 17:06:56 -0800 (PST)

To: <commander-list(at)matronics.com>

Subject: Re: Commander-List: Flight Levels magazine - Fall 2008 issue

  = Gents,

The following was gleaned from=  the production data on the commander website and from the NACA archives.</= FONT>

 <?xml:namespace prefix =3D o ns =3D "urn:schema= s-microsoft-com:office:office" />

There appears to be two variants of the commander wing; a  44=92 and a 49=92  Both variants use the NACA 23012 airfo= il from root to tip.   T= his particular airfoil is know for its docile behavior and was widely used = by other aircraft.  Most nota= bly the Beech Staggerwing uses this airfoil as do other Beech Aircraft, but=  only in the outboard sections near the ailerons.  The Commanders use a single airfoil from root to tip.=  This was chosen likely for = its ease of manufacture.  Fro= m a manufacturing standpoint, adding 5=92 to the wingspan is easier to do b= y either  lengthening the tips outboard of the ailerons or increasing the engine/nac= elle truss section. This could mean adding just one or two rib sections

The 49=92 wing is the archetype and is featured on all the = piston twin commanders except the so-called =93straight=94 560 and 680 mode= ls.  The 560 was produced fro= m 1954 to 1957 and the 680 ran from =9255 to =9258.

There is also a notable difference in the fuel capacity for=  the 44=92 560 which has 145 gals compared to the 500s which have 156 gallo= ns normally.  All the Long ra= nge models of 560E, F and 680F, L,P have 223 gallons  apparently using all the available bays inboard of=  the ailerons. 

As for weight. It looks like the early models (round nacell= e) had usefull loads around 2100 lbs with variations trading up or down dep= ending on HP and Service ceiling.  <= /SPAN>Twin Commander corporation has mentioned that they don=92t have model=  years, per-se; so this has allowed them to make production runs of a parti= cular type using the same production space.

When the Streamlined Nacell was introduced, there was also = a notable increase in useful load. To about 2300  to 3200 lbs.  <= /SPAN>This also improved their service ceiling from an average of 22 kft. T= o 28kft in the E and F models.

I/ve been chasing this trail during my search for the =93Ri= ght=94 Commander to buy.  Ive=  focused on a 680F for a lot of reasons, but mostly it has the widest range=  of operating capability, short field, high(er) altitude and still have a m= odicum of efficiency for its type. (if you can keep your hand off the throt= tle). 

wer

--- On Sat, 11/8/08, John Vormbaum <john(at)vormbaum.com= > wrote:

[quote]From: John Vormbaum <john(at)vormbaum.com>

Subj= ect: Re: Commander-List: Flight Levels magazine - Fall 2008 issue

To: co= mmander-list(at)matronics.com

Date: Saturday, November 8, 2008, 1:29 PM

=

[quote]--> Commander-List message posted by: John Vormbaum <john(at)vo= rmbaum.com>  Jim,  I thought the wing & spar structures were the same on all the Commander= s. They're not? I know the turbines are easily a 12,000-lb. wing, but I've been under the illusion that the wing on my 500B is essentially the same thing...  /John  willis robison wrote: > I think so too. >  I was a spectator at a few "ultimate" load tests.  One for the A380.  I was told that it took 10x the "rated" load before failing.=20 They said they were pleased with the results so I guess it made it past FAA=  and JAR. >=20 > --- On *Sat, 11/8/08, yourtcfg(at)aol.com /<yourtcfg(at)aol.com>/* wro= te: >=20 >     From: yourtcfg(at)aol.com <yourtcfg(at)aol.com> >     Subject: Re: Commander-List: Flight Levels magazine - Fall 2008 is= sue >     To: commander-list(at)matronics.com >     Date: Saturday, November 8, 2008, 10:33 AM >=20 >     Over designed I think.  The same airframe wing structure can carry >     as much as 8500 pounds, thought some Commanders are limited to >     6000 gross.  The gross weight is determined by the FAA mandated >     single engine climb performance.  A model 680 has the same power >     as a 680E but a 500 pound lower gross.  Some 680s were extended to >     the "E" wingspan and the gross went up to 7500 pounds.  jb >=20 >         Which was it and at what HP/gross is the maximum? >=20 >=20 >=20 >=20 >     --

yourtcfg(at)aol.com
Guest

Posted: Sat Nov 08, 2008 7:04 pm Post subject: Flight Levels magazine - Fall 2008 issue

HI JOHN...

 Nope, when Commander built the first 690 series airplane, the used a completely different wing structure.  You can easily tell the change by looking at the airplane from the nose, the higher gross turbines have a short center section that extends straight out from the cabin, then the dihedral.  It is in effect a "gull wing".   Lower gross airplanes, like yours and mine, have the dihedral at the center of the wing.  The reason for the change was to move the turbines out further from the cabin and allow for larger diameter propellers.  jb

   	  Quote: 	
		   

 I thought the wing & spar structures were the same on all the Commanders. They're not? I know the turbines are easily a 12,000-lb. wing, but I've been under the illusion that the wing on my 500B is essentially the same thing... 

  	


 

 

 --

John Vormbaum

Joined: 21 Aug 2006
Posts: 273
Location: SF Bay Area, CA

Posted: Sat Nov 08, 2008 8:36 pm Post subject: Flight Levels magazine - Fall 2008 issue

I'll definitely take a close look the next time I see a 500-series and a 

690-series airplane side by side!



Thanks for the clarification & education on the particulars of Commander 

wings.



/J



yourtcfg(at)aol.com wrote:

[quote] HI JOHN...

 Nope, when Commander built the first 690 series airplane, the used a 

 completely different wing structure.  You can easily tell the change 

 by looking at the airplane from the nose, the higher gross turbines 

 have a short center section that extends straight out from the cabin, 

 then the dihedral.  It is in effect a "gull wing".   Lower gross 

 airplanes, like yours and mine, have the dihedral at the center of the 

 wing.  The reason for the change was to move the turbines out further 

 from the cabin and allow for larger diameter propellers.  jb



      

     I thought the wing & spar structures were the same on all the

     Commanders. They're not? I know the turbines are easily a

     12,000-lb. wing, but I've been under the illusion that the wing on

     my 500B is essentially the same thing... 

      





 --

nico(at)cybersuperstore.c
Guest

Posted: Sat Nov 08, 2008 9:40 pm Post subject: Flight Levels magazine - Fall 2008 issue

I didn't know that. I'll be looking out for that too.

 



--

barry.collman(at)air-brit
Guest

Posted: Sun Nov 09, 2008 3:13 am Post subject: Flight Levels magazine - Fall 2008 issue

Hi All,

  

 A factory document in my collection titled  "Aircraft Evolution", tells us the following about the Commander  wings:

  

 Wing Drawing 5170000 - Models L-3805, 520 &  560.

 Wing Drawing 5170023 - Models 560A &  680.

 With the 32-inch wing tip extension - Models  560E, 680E, 720 & 500.

 Wing Drawing 5170045 - Models 500A, 500B,  680F, 680F(P) & 560F.

 Modified 5170045 for "8500lb" Wing - Models  500U & 500S. (Hence Certified in Utility & Standard  category).

 Removed 32-inch wing tip extension - Models 680T,  680V, 680W & 681.

 Added 30 inches at wing center section - Models  690, 685, 690A & 690B.

 Added 30-inch wing tip extension - Models 690C,  695, 690D, 695A & 695B.

  

 I think the basic wing structure remained the  same, the factory "simply" adding extensions either inboard or  outboard.

 Capt. JimBob is, of course, right.

 The 15" inboard extension each side for the 685  and from the early 690 series did not have any dihedral.

  

 Very Best Regards,

 Barry

  

 [quote]   ---

steve2(at)sover.net
Guest

Posted: Sun Nov 09, 2008 4:50 am Post subject: Flight Levels magazine - Fall 2008 issue

WER,

  

 Barry this morning has added some drawing number  detail to the wing history.

  

 I 'know' enough to perhaps comment, but not so much  that I might not get it completely right..... So hopefully somebody will correct  me where I'm in error.....

  

 Because of early problems with spars cracking caps  the factory took different approaches to effecting a repair. Some of this I  believe is also partly responsible for some changes in gross. The 500 series is  a good case study. Our 500B has external heavy aluminum spar straps. They look  like leaf springs. We have a lower gross than the 500U and 500S, which has  longer internal strapping of the cap in stainless steel. The 'fix' created its  own problem of galvanic corrosion between dissimilar metals, which remains an  issue to this day. So we have a lower gross, but don't have the corrosion  problem of the models with the higher gross. (The 500B is better looking too, in  a full-figured kind of way!)

  

 Somebody correct me where I'm wrong. (And on this  list, I can't imagine not being corrected if anyone thinks I'm  wrong!)

  

 The wings are beautiful in a way books  and figures can't convey. Take a look at the twist in the wing on its way  outboard.

  

 My Dad spent a lot of time is mainly 680E's all  over the world. He loved them, but I believe he thought the 680F the best of  breed.

  

 Ok, now to see if I can get the bulldozer fixed.  Sigh........

  

 Steve 

 [quote]   ---

barry.collman(at)air-brit
Guest

Posted: Sun Nov 09, 2008 5:02 am Post subject: Flight Levels magazine - Fall 2008 issue

Hi All,

  

 The typical wing twist aspect is indeed  interesting.

  

 Looking at the 560E, for example,  the incidence at the wing root was 3 degrees. while that at the tip  was minus 3.5 degrees.

  

 Looking at the 560A, for example,  the incidence at the wing root was 3 degrees. while that at the tip  was minus 1 degree.

  

 Best Regards,

 Barry

 [quote]   ---

BobsV35B(at)aol.com
Guest

Posted: Sun Nov 09, 2008 5:41 am Post subject: Flight Levels magazine - Fall 2008 issue

Good Morning Steve,

  

 While I had the pleasure of flying several of the early model Aero  Commanders forty-five to fifty years ago, I have NEVER worked on one and have  absolutely NO knowledge as to how they are built. 

  

 Nevertheless, may I make a comment?

  

 Just because the wing on two different models happens to look the same does  not mean the strength is the same. Adding a full web to a spar that previously  used a Warren or Pratt truss can makes a major difference as can increasing the  skin thickness of a rib or a D-tube leading edge.  The very earliest,  lightest weight, and weakest Bonanza wing can be physically bolted on to a Twin  Bonanza. All control surfaces will hook up properly with no problems at all. The  only thing that won't work is the landing gear. Some method would have to be  devised to keep the landing gear doors closed, but the airplane could be flown.  The wing would not be as strong as is needed to meet the FAA requirements, but  it would fly and only a close examination of the wing would reveal that there  were small visible changes.

  

 May I not assume that the engineers who designed the Aero  Commander used similar techniques to both lighten the structure where high loads  were not required and beef the structure where high loads were to be  carried?

  

 Happy  Skies



Old Bob

AKA

Bob Siegfried

Ancient Aviator

628 West 86th  Street

Downers Grove, IL 60516

630 985-8502 

Stearman  N3977A

Brookeridge Air Park LL22   

  In a message dated 11/9/2008 6:51:44 A.M. Central Standard Time,  steve2(at)sover.net writes:

  	  Quote: 	
		      

   Because of early problems with spars cracking    caps the factory took different approaches to effecting a repair. Some of this    I believe is also partly responsible for some changes in gross. The 500 series    is a good case study. Our 500B has external heavy aluminum spar straps. They    look like leaf springs. We have a lower gross than the 500U and 500S, which    has longer internal strapping of the cap in stainless steel. The 'fix' created    its own problem of galvanic corrosion between dissimilar metals, which remains    an issue to this day. So we have a lower gross, but don't have the corrosion    problem of the models with the higher gross. (The 500B is better looking too,    in a full-figured kind of  way!)

	






AOL Search: Your one stop for directions, recipes and all othe82x1200798498/aol?redir=http://searchblog.aol.com/2008/11/04/happy-holidays-from-aol-search/?ncid=emlcntussear00000001 ">Search Now.

  [quote][b]

cschuerm(at)cox.net
Guest

Posted: Sun Nov 09, 2008 7:10 am Post subject: Flight Levels magazine - Fall 2008 issue

Barry Collman wrote:

 	  Quote: 	
		   I think the basic wing structure remained the same, the factory 

 "simply" adding extensions either inboard or outboard.


	


Barry,

Do the drawings you have show the internal structure in detail?  If so, 

I'd love to see them. Although the Commander wings appear to be 

virtually identical externally, I believe there are many structural 

differences internally.  I certainly have not had the opportunity to 

compare the wings closely, but from my casual viewing through inspection 

holes, I believe there are very substantial and subtle upgrades in the 

strength of the structure as the line progressed.



Chris

barry.collman(at)air-brit
Guest

Posted: Sun Nov 09, 2008 7:51 am Post subject: Flight Levels magazine - Fall 2008 issue

Chris,



I don't have the actual Drawings, just a document detailing the basic changes 

from one Model to another, grouped by the wing  detail.



Best Regards,

Barry



---

drwer2

Joined: 24 Sep 2008
Posts: 41
Location: Squaw Valley, CA

Posted: Sun Nov 09, 2008 8:51 am Post subject: Flight Levels magazine - Fall 2008 issue

Now,thats interesting.  The effect of increasing the "washout" is to (a). move the center of lift inboard, (b.) decrease overall lift and (c) improve slow speed handling and stall characteristics. These are subtle changes.  This change would not have a major effect on MTOW but would place the stress where the wing was stronger. 

 

I'd give anything to see any production drawings.

 

Thanks again Barry for being our Nexus.

 

Willis

 

--- On Sun, 11/9/08, Barry Collman <barry.collman(at)air-britain.co.uk> wrote:



From: Barry Collman <barry.collman(at)air-britain.co.uk>

Subject: Re: Flight Levels magazine - Fall 2008 issue

To: commander-list(at)matronics.com

Date: Sunday, November 9, 2008, 5:00 AM



Hi All,

 

The typical wing twist aspect is indeed interesting.

 

Looking at the 560E, for example, the incidence at the wing root was 3 degrees. while that at the tip was minus 3.5 degrees.

 

Looking at the 560A, for example, the incidence at the wing root was 3 degrees. while that at the tip was minus 1 degree.

 

Best Regards,

Barry



---

_________________
No Generality is worth a damn....including this one.

cogito ergo aero-geek

John Vormbaum

Joined: 21 Aug 2006
Posts: 273
Location: SF Bay Area, CA

Posted: Sun Nov 09, 2008 9:09 am Post subject: Flight Levels magazine - Fall 2008 issue

Willis,



My money is on reason "c". The washout on the Commanders was primarily 

to aid in low-speed handling; you want the wing root to stall before the 

tip so that you can maintain directional control. I've heard it cited 

that this is the reason that during his famous routine Bob Hoover was 

able to fly the airplane vertically to near-zero airspeed, but still 

have aileron authority and not drop a wing. I don't know if that's the 

honest truth, but we all know how well these airplanes do at low speed.



I would think that using washout to decrease overall lift is 

inefficient; you could just use less wing and get better performance 

numbers, right? I'm sure someone will correct me if I'm wrong!



/John



willis robison wrote:

[quote] Now,thats interesting.  The effect of increasing the "washout" is to 

 (a). move the center of lift inboard, (b.) decrease overall lift and 

 (c) improve slow speed handling and stall characteristics. These are 

 subtle changes.  This change would not have a major effect on MTOW but 

 would place the stress where the wing was stronger. 

  

 I'd give anything to see any production drawings.

  

 Thanks again Barry for being our Nexus.

  

 Willis

  

 --- On *Sun, 11/9/08, Barry Collman 

 /<barry.collman(at)air-britain.co.uk>/* wrote:



     From: Barry Collman <barry.collman(at)air-britain.co.uk>

     Subject: Re: Flight Levels magazine - Fall 2008 issue

     To: commander-list(at)matronics.com

     Date: Sunday, November 9, 2008, 5:00 AM



     Hi All,

      

     The typical wing twist aspect is indeed interesting.

      

     Looking at the 560E, for example, the incidence at the wing

     root was 3 degrees. while that at the tip was minus 3.5 degrees.

      

     Looking at the 560A, for example, the incidence at the wing

     root was 3 degrees. while that at the tip was minus 1 degree.

      

     Best Regards,

     Barry



         ---

drwer2

Joined: 24 Sep 2008
Posts: 41
Location: Squaw Valley, CA

Posted: Sun Nov 09, 2008 10:01 am Post subject: Flight Levels magazine - Fall 2008 issue

I think you're right on the money John. Ill bet that was the intent and the other effects were probably insignificant and  just trade offs.

  

 wer.



--- On Sun, 11/9/08, John Vormbaum <john(at)vormbaum.com> wrote:



 [quote]From: John Vormbaum <john(at)vormbaum.com>

Subject: Re: Flight Levels magazine - Fall 2008 issue

To: commander-list(at)matronics.com

Date: Sunday, November 9, 2008, 9:09 AM



[quote]--> Commander-List message posted by: John Vormbaum <john(at)vormbaum.com>  Willis,  My money is on reason "c". The washout on the Commanders was primarily to aid in low-speed handling; you want the wing root to stall before the tip so that you can maintain directional control. I've heard it cited that this is the reason that during his famous routine Bob Hoover was able to fly the airplane vertically to near-zero airspeed, but still have aileron authority and not drop a wing. I don't know if that's the honest truth, but we all know how well these airplanes do at low speed.  I would think that using washout to decrease overall lift is inefficient; you could just use less wing and get better performance numbers, right? I'm sure someone will correct me if I'm wrong!  /John  willis robison wrote: > Now,thats interesting.  The effect of increasing the "washout" is to (a). move the center of lift inboard, (b.) decrease overall lift and (c) improve slow speed handling and stall characteristics. These are subtle changes.  This change would not have a major effect on MTOW but would place the stress where the wing was stronger.  I'd give anything to see any production drawings. >  Thanks again Barry for being our Nexus. >  Willis >   >  > --- On *Sun, 11/9/08, Barry Collman /<barry.collman(at)air-britain.co.uk>/* wrote: >  >     From: Barry Collman <barry.collman(at)air-britain.co.uk> >     Subject: Re: Flight Levels magazine - Fall 2008 issue >     To: commander-list(at)matronics.com >     Date: Sunday, November 9, 2008, 5:00 AM >  >     Hi All, >          The typical wing twist aspect is indeed interesting. >          Looking at the 560E, for example, the incidence at the wing >     root was 3 degrees. while that at the tip was minus 3.5 degrees. >          Looking at the 560A, for example, the incidence at the wing >     root was 3 degrees. while that at the tip was minus 1 degree. >          Best Regards, >     Barry >  >         ---

_________________
No Generality is worth a damn....including this one.

cogito ergo aero-geek

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