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Cable Tensions for 601XL?
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amyvega2005(at)earthlink.
Guest

Posted: Wed Nov 12, 2008 1:37 pm Post subject: Cable Tensions for 601XL?

not having elevator trim limits the plane's power to weight true speed capabilitys. You pitch/ trim for speed and throttle for climb.  If no trim avaialable than the plane will be set a level flight at a certain horsepower and as weight changes the level flight/ horse power output will change.  



Cable tension is a whole differnt ball of wax.  The Tension AD is out there because people did not focus on it as that important and it bit some folks in the ass, and then they blame it on the design.



Juan



--

amyvega2005(at)earthlink.
Guest

Posted: Wed Nov 12, 2008 1:38 pm Post subject: Cable Tensions for 601XL?

every pilot flys their plane with the trim.  makes for better and smooth flying. a plane with now trim is limitred in its true capabilities and so is the pilot.



Juan



--

notsew_evets(at)frontiern
Guest

Posted: Wed Nov 12, 2008 3:24 pm Post subject: Cable Tensions for 601XL?

P factor and  torque is corrected by left or right engine mount setting.  OR 

rudder offset.   I understand that Sabrina was talking about climb and 

desent.  With power or not the attitude (verticle) should not change a whole 

bunch.



---

hills(at)sunflower.com
Guest

Posted: Wed Nov 12, 2008 4:10 pm Post subject: Cable Tensions for 601XL?

My 601HDS propeller fluttered too !!!!  

Then it broke off.  

   

   

Roger  

   

         

  

From: owner-zenith-list-server(at)matronics.com [mailto:owner-zenith-list-server(at)matronics.com] On Behalf Of J.T. Machin

 Sent: Wednesday, November 12, 2008 11:49 AM

 To: zenith-list(at)matronics.com

 Subject: Re: Re: Cable Tensions for 601XL?  

  

           

Sabrina,

   

   I have to agree with Wade.  Every aircraft's control system is different   and and the fact that the ailerons have a balance cable really does not   impact its flutter characteristics because flutter is not really a control   surface deflection that originates from the stick.  The deflection comes   from a flexing of the system that then stores the spring energy.  This   flexing and storing of energy and then releasing that energy as the surface   unflexes is a primary driver in the creation of the flutter effect.    That is why stiffer is better when it comes to control systems.

   

   That being said, a flutter situation can occur in any of the control   surfaces.  As the XL has had several reported instances of aileron   flutter, it seems to be the most prevalent flutter mode.  I have not   heard of any report instances of elevator flutter.  Also, any additional   weight at the trailing edge of a control surface will absolutely reduce the   flutter speed.  I'm not saying that the XL with aileron trim is unsafe,   but it does have less flutter margin than one without the trim system.

   

   I decided to go with a bungee type trim if required for the the ailerons.

   

   Jim Machin

   601XL, 0-200

   Almost done!

   

   --- On Wed, 11/12/08, Sabrina <chicago2paris(at)msn.com>   wrote:   

From: Sabrina   <chicago2paris(at)msn.com>

   Subject: Re: Cable Tensions for 601XL?

   To: zenith-list(at)matronics.com

   Date: Wednesday, November 12, 2008, 8:24 AM    	  Quote: 	
		  --> Zenith-List message posted by: "Sabrina"

<chicago2paris(at)msn.com>

  

"I did use elevator trim."

  

Wade,

  

Personally, the elevator trim weight bothered me more than the aileron trim.  

The ailerons, by their nature of one being up and one down, should, if properly

tensioned, be easier to dampen in flight than a fluttering elevator.  So too, a

builder can easily adjust an XL's horizontal stabilizer for proper cruise

configuration since it sits so high off the longerons.    The aileron trim was a

much easier call for me than the elevator trim.  If no aileron trim under Par.

4-36, why elevator trim?

  

As to Par 4-36(c) was it the Cardinal that used foam in the elevator trim tab

that took on water/ice and threw it off balance?

  

Has anyone had to drill a weep hole in their elevator trim tab to make sure ice

does not build up?   I ended up gust-locking my elevator in the up position

rather than down to keep the ice out.

  

  

  

  

Read this topic online          	
     

   

        [quote][b]

n801bh(at)netzero.com
Guest

Posted: Wed Nov 12, 2008 5:09 pm Post subject: Cable Tensions for 601XL?

Miss Sabrina,,,, I could go back through all of your emails and point out every detail you have wrong, in fact I still might, But. Until you strap you own butt in the seat of the plane you claim you built and actually get it in the air your comments are second hand gossip.  Funny you answered all the other questions except for the one asking why you don't fly your own plane..  

Stay tuned for the regular scheduled program already in progress. 

do not archive



Ben Haas

N801BH

www.haaspowerair.com



-- "Sabrina" <chicago2paris(at)msn.com> wrote:

--> Zenith-List message posted by: "Sabrina" <chicago2paris(at)msn.com>



Mr. Haas,



The problem here is that I am sending someone else up in my aircraft every time I authorize a new test flight.  It is a very serious task, especially the first flight after each XL fatality.  



The rudder tension numbers bothered me and that is why I did not sign the aircraft off for the next flight until I figured it out.  (Remember now, the IA did not adjust the rudder tensions.)  I posted the numbers here and you guys, albeit off list, confirmed my problem with the numbers.  Since I have 33% more bearing surface than you guys on the rudder, 5 more pounds of tension than the Haas 30 +/- 5 is nominal, but not optimal.  



Most newer, light-engine 601s have a higher 'at rest' rudder tension because the stop plate is at or nearly at rest.  My nose heavy aircraft, and those with more time on their bungee will see their at rest rudder tensions drop.  Each of us should expect a different at rest value and something other than my 12-13 pound differential between rest and flight.  



Although I know my particular airframe "at rest" better than anyone, and had to defend my modifications to it during hours of meetings last December and January, since I have never flown it or in it, I have to rely upon others in situations involving the feel of the aircraft in flight.   For example, the rudder is often described in post-flight briefings as heavy, the ailerons medium and the elevator light as compared to my Cessna 150L.   My test pilot actually flies my C150L first and then flies the Sabrina.  Although they are different animals, they do share many features including a common engine/prop.  This nearly contemporaneous comparison gives me the only "feel" I have for the Sabrina in flight and takes away the "local conditions" factor that might otherwise taint the comparison.





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=213742#213742

<========================sp;                       &nb========================================================================;           - MAT==========================================

 



_____________________________________________________________

Click here to find the satellite television package that meets your needs.

   [quote][b]

Gig Giacona

Joined: 10 Jan 2006
Posts: 1416
Location: El Dorado Arkansas USA

Posted: Wed Nov 12, 2008 5:38 pm Post subject: Re: Cable Tensions for 601XL?

 	  gburdett wrote: 	
		  And I'm a 7 year old Dalmatian whose owner taught to fly using hand signals. Give it a rest.



Update: Aren't you in school today? Not bothered-get cranky a lot though. Sometimes too experimental. You seem to have an innate grasp of aeronautical topics-do you have a mentor or read a lot?



DO NOT ARCHIVE 	




Well she built a plane.

_________________
W.R. "Gig" Giacona
601XL Under Construction
See my progress at www.peoamerica.net/N601WR

hills(at)sunflower.com
Guest

Posted: Wed Nov 12, 2008 6:31 pm Post subject: Cable Tensions for 601XL?

Like I always say, flying is only part of aviation, and not necessarily the

best part.



Roger



--

ideaz1(at)sbcglobal.net
Guest

Posted: Wed Nov 12, 2008 6:31 pm Post subject: Cable Tensions for 601XL?

Sorry, no offense Steve, but I agree with Juan on this one. Simple test... 

fly straight and level then cut throttle to idle while holding the elevator 

steady. I promise you that ANY plane will soon be in a steep dive toward the 

ground. Full power  from straight and level (if your trimmed  for level at 

low power) and you will pitch up and climb. I thought we all knew this

---

stormyflight(at)yahoo.com
Guest

Posted: Wed Nov 12, 2008 6:48 pm Post subject: Cable Tensions for 601XL?

Wow Ben,



I am surprised at your response to such a talented and well educated email from Sabrina.



I have never seen anyone accomplish so much and have so much eloquence from so one so young.   Her enthusiasm is contagious and am honored to discuss such issues with her.



This is coming from one who has been in the aerospace business for over 25 years and has designed 12 aircraft,(some I expect that you have heard of; Predator and Reaper UAV's which are currently performing the majority of the Air Force missions overseas).



I for one look forward to Sabrina's comments and while I don't always agree, I do feel that I am exchanging with an aerospace engineer with many years of experience.   I truly applaud all of you accomplishments to date.  At her age I was still shaping balsa wood sticks for my free flight model  airplanes and hoping for a trophy at the local model aircraft contest.



By the way, Sabrina, if you are looking for a summer internship at a state of the art aerospace company once you start your college career, contact me off line.  I am sure we can work something out.



Jim Machin

Director of Advanced Development

General Atomic Aeronautical Systems



--- On Wed, 11/12/08, n801bh(at)netzero.com <n801bh(at)netzero.com> wrote:

[quote]From: n801bh(at)netzero.com <n801bh(at)netzero.com>

Subject: Re: Re: Cable Tensions for 601XL?

To: zenith-list(at)matronics.com

Date: Wednesday, November 12, 2008, 5:08 PM



Miss Sabrina,,,, I could go back through all of your emails and point out every detail you have wrong, in fact I still might, But. Until you strap you own butt in the  seat of the plane you claim you built and actually get it in the air your comments are second hand gossip.  Funny you answered all the other questions except for the one asking why you don't fly your own plane..  

Stay tuned for the regular scheduled program already in progress. 

do not archive



Ben Haas

N801BH

www.haaspowerair.com



-- "Sabrina" <chicago2paris(at)msn.com> wrote:

--> Zenith-List message posted by: "Sabrina" <chicago2paris(at)msn.com>



Mr. Haas,



The problem here is that I am sending someone else up in my aircraft every time I authorize a new test flight.  It is a very serious task, especially the first flight after each XL fatality.  



The rudder tension numbers bothered me and that is why I did not sign the aircraft off for the next flight until I figured it out.  (Remember now, the IA did not adjust the rudder tensions.)  I posted the numbers here and you guys, albeit off list, confirmed my problem with the numbers.  Since I have 33% more bearing surface than you guys on the rudder, 5 more pounds of tension than the Haas 30 +/- 5 is nominal, but not optimal.  



Most newer, light-engine 601s have a higher 'at rest' rudder  tension because the stop plate is at or nearly at rest.  My nose heavy aircraft, and those with more time on their bungee will see their at rest rudder tensions drop.  Each of us should expect a different at rest value and something other than my 12-13 pound differential between rest and flight.  



Although I know my particular airframe "at rest" better than anyone, and had to defend my modifications to it during hours of meetings last December and January, since I have never flown it or in it, I have to rely upon others in situations involving the feel of the aircraft in flight.   For example, the rudder is often described in post-flight briefings as heavy, the ailerons medium and the elevator light as compared to my Cessna 150L.   My test pilot actually flies my C150L first and then flies the Sabrina.  Although they are different animals, they do share many features including a common engine/prop.   This nearly contemporaneous comparison gives me the only "feel" I have for the Sabrina in flight and takes away the "local conditions" factor that might otherwise taint the comparison.





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p 13742#213742

<========================sp;                       &nb========================================================================;           - MAT==========================================

 



_____________________________________________________________

Click here to find the satellite television package that meets your needs.

              [quote][b]

ideaz1(at)sbcglobal.net
Guest

Posted: Wed Nov 12, 2008 7:01 pm Post subject: Cable Tensions for 601XL?

Back to the cable tension debate, if I may, with all the discussions of 

cables and flutter I am more convinced than ever to use pushrods, and 

balanced control surfaces. To me, this is a simple, logical fix. I'm not the 

first person to do this, and probably not the last. pushrods never need 

tension adjusting, they do not put a permanent strain on the airframe like 

cables do. If there is any play from worn parts you can tell instantly on 

your pre-flight.

As to balance of controls this further relieves stress on the airframe and 

if I'm not mistaken helps reduce the possibility of flutter.



I frankly don't care if Zenith Inc. doesn't like this but it is obviously 

very hard and embarassing for a company to admit that they could have done 

better and make changes to their design, admitting to those weaknesses in 

their design, so I use my own experience and compare this plane to other 

designs that have done a better job on some of these issues. I didn't invent 

pushrods and balanced ailerons, but I have flown some exceptional planes 

that had them so why not.. I'm sure I'm not the only person to write to Mr 

Heinz about this issue and the wing failure issue only to get the pat 

response that "there are hundreds of these planes flying so it must be OK" 

Well maybe most people don't get close to the design limits of their planes 

and never find out the hard way that they are borderline in some areas and 

you only get one chance to cross that line.



I still like the plane and plan to build it, but I'll fix these obvious (in 

my opinion) weaknesses.



Dirk

PS Let the flames begin, I'm ready for you!

psm(at)att.net
Guest

Posted: Wed Nov 12, 2008 7:05 pm Post subject: Cable Tensions for 601XL?

Hi Sabrina,



I promise not to ever underestimate you.  Indeed, I am incredibly 

impressed with you.



That said, I must take issue with your comment that riveting a kit 

together is a no-brainer.  I managed to destroy my first XL wing by 

trying my best to follow the instructions provided by ZAC.  After 

scrapping it I decided to mostly ignore the kit instructions and 

think through the process of building each piece into the finished 

airframe.  There was also much fitting and remaking of parts I 

destroyed on my first attempts.



I have found the entire process of building an XL from standard kit 

very educational.  I have been working on mine for over three years 

now (but only an hour or two per day) and I still seem to learn 

something new every day.



Indeed, I think my brain is the part that has had to work the hardest 

building this kit.



Best regards,



Paul

XL getting close

At 06:00 PM 11/12/2008, you wrote:

 	  Quote: 	
		  



  You are not the first and will not be the last to underestimate me.

  Actually riveting together an airframe kit is a no brainer.

craig(at)craigandjean.com
Guest

Posted: Wed Nov 12, 2008 8:13 pm Post subject: Cable Tensions for 601XL?

And now they fly Rotax-powered UAVs. I think I'm happier with their present

incarnation 



-- Craig



Do not archive



--

hills(at)sunflower.com
Guest

Posted: Wed Nov 12, 2008 10:06 pm Post subject: Cable Tensions for 601XL?

Ya, I guess nuclear reactors falling from the sky was not a very great

concern at the time.



Roger

--

craig(at)craigandjean.com
Guest

Posted: Wed Nov 12, 2008 10:16 pm Post subject: Cable Tensions for 601XL?

Project Orion wasn't powered by a reactor - it was powered by a series of

small atomic bombs:



http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)



I'm certain the cable tension would have been critical 



--  Craig



Do not archive

--

hills(at)sunflower.com
Guest

Posted: Thu Nov 13, 2008 5:11 am Post subject: Cable Tensions for 601XL?

Oh well, now I feel better.



Roger




Project Orion wasn't powered by a reactor - it was powered by a series of

small atomic bombs:



http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)



I'm certain the cable tension would have been critical 



--  Craig



Do not archive

--

amyvega2005(at)earthlink.
Guest

Posted: Thu Nov 13, 2008 6:02 am Post subject: Cable Tensions for 601XL?

Dirk,

A look at 90 percent of GA aircraft, including quite  few few Jets,  show that they use cables.  The rods are no better than the cables.  the flaw is in the builders not following simple directions to tesnionthe cable.  Maybe its becasue cable need vigialance more so than rods.  Cables need to be retightened from time to time and maintained.  Its not the cable design, its the builders.  We are the builders and its funny how people blame everything but the builders.  

If I have a problem with my plane,  and it is due to something I over looked or neglected,  I just look in the mirror as to placing the blame.    I believe quite comfortably the design of the aircraft is quite sound.  The problems lie  in the build and most,  the maintenance.  Tension the cables, and swage them correctly, and you will be fine,  if cables were an issue ,  they wopuild not have them on most Boeing and Airbus aircraft.

Juan



Juan



--

amyvega2005(at)earthlink.
Guest

Posted: Thu Nov 13, 2008 6:11 am Post subject: Cable Tensions for 601XL?

Thanks DIrk,

Its called Dynamic stability.  All plane fly as speed regulated by pitch (trim) and throttle for decent and accent.(lift, weight, drag, thrust)...

I hear you on the cable vs rod debate  ,  i think its not the design though,  its the maintenacne issue.  ALot of guys building,  build their planes and do not realize the maintenance requirement involved.  Cables are not set and forget.  Maybe that would be the strenght of Rods.   I think where allt he accidents have happened for the ecception of a few has been oversight on the ground. A bolt not tightened, a cable not propoerly swaged. Someone second guessing the plans and over torquing, etc...

Juan



--

amyvega2005(at)earthlink.
Guest

Posted: Thu Nov 13, 2008 6:13 am Post subject: Cable Tensions for 601XL?

next time balance the prop,  people tend to forget that little part.



--

gburdett

Joined: 05 Aug 2008
Posts: 13

Posted: Thu Nov 13, 2008 6:21 am Post subject: Re: Cable Tensions for 601XL?

Yes Gig, I stand corrected.

notsew_evets(at)frontiern
Guest

Posted: Thu Nov 13, 2008 7:36 am Post subject: Cable Tensions for 601XL?

Its ok, no offense taken.  We all "discuss" what we have learned over 

theyears we have  been involved in this hobby.

One of my airplanes would not climb as advertised.  I would fly along side 

other aircraft ( same make and models) and these guys always out climbed me 

by at lease 400 FPM.

One day a builder suggested I look at the upward thrust of the engine mount. 

Sure enough,  the engine crank shaft pointed down.  Waaaay down....

Just a few washers under the bottom attach bolts took care of the problem.

Sure if the pilot reduces power the nose will drop, but not much.  Just 

enough to maintain the current trim speed...

I think if the power was reduced and the airplane nose went straight down, 

there is a problem.   On the other hand, and this example is waaay out,  if 

your aircraft, model X65-970, is in level, trimmed flight and the pilot goes 

full throttle, and it loops....youve got a problem....

Its not trim, its not angle of incidence.  It might be engine position.



Goofy aint I ????



I accept being wrong..   But if so, geeze there are a lot of student pilots 

out there flying with my spew of  B.S.



Hey,  I m the guy who cant even get my 601XL to balance within the 

envelope....



---

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