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XL Testing UK
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s.clive.richards(at)homec
Guest

Posted: Mon Jun 15, 2009 1:14 am Post subject: XL Testing UK

All XL Builders 

From our LAA WEB SITE 

Testing of Chris Heinz mods appears to be immanent  and may resolve your problems. 

Clive 

Permission to test fly Zenair CH 601 XL  Granted by UK CAA 

  

Following a briefing meeting at Gatwick with the CAA flutter  and structures experts, the CAA has now given permission for the LAA to start  the flight program on a modified Zenair CH601 XL fitted with aileron mass  balances and wing attachment reinforcements. This permission temporarily exempts  the aircraft from the MPD which currently grounds the type, so that the  effectiveness of the modifications can be explored.  LAA Engineering are  now awaiting the arrival of the test equipment which has been specified to  record the behaviour of the airframe during the flutter testing. Once the  equipment is installed and wired up, flight tests will explore the ASI  calibration, flutter behaviour, cg range, pitch stability and the sensitivity of  the elevator trim tab. The flight testing will take place from a farm strip near  Cambridge.  

 

   [quote][b]

jaybannist(at)cs.com
Guest

Posted: Mon Jun 15, 2009 5:53 am Post subject: XL Testing UK

Clive,

 

 "May resolve your problems"?? Must the scientific community go back and prove to the British CAA Bureaucrats that the world is round ?    The Zodiac XL has been load tested twice, passing both times. The German scientists PROVED that there is NOT a flutter problem with the XL, and yet the Brits insist on testing a solution to a problem that doesn't exist. Is it because they didn't do the tests themselves that they have totally disregarded all the testing that has been done on the XL ??   I guess we MUST allow that the Brit Bureaucrats' intelligence is superior to that of everyone else in the world.  Talk about hard-headed arrogance !!

 

 Jay Bannister

 Do not archive

 

   

 

   

 

 --

jmaynard

Joined: 27 Feb 2008
Posts: 394
Location: Fairmont, MN (FRM)

Posted: Mon Jun 15, 2009 6:19 am Post subject: XL Testing UK

On Mon, Jun 15, 2009 at 09:51:11AM -0400, jaybannist(at)cs.com wrote:

 	  Quote: 	
		   The Zodiac XL has been load tested twice, passing both times.


	


Static load testing, only...good in and of itself, but not everything.



 	  Quote: 	
		   The German scientists PROVED that there is NOT a flutter problem with the

 XL, and yet the Brits insist on testing a solution to a problem that

 doesn't exist. Is it because they didn't do the tests themselves that they

 have totally disregarded all the testing that has been done on the XL ????


	


There's one thing that the German testing didn't cover: what happens if

there's no tension on the aileron cables? It's well and good in the US to

say that the cable tensions must be maintained as a sufficient solution to

the problem, but the accepted standard in the aeronautical engineering world

is to have no flutter issues with slack cables. The Germans didn't test that

scenario. It's not unreasonable for the British to say that cable tension

alone is not sufficient.



 	  Quote: 	
		   I guess we MUST allow that the Brit Bureaucrats' intelligence is superior

 to that of everyone else in the world.? Talk about hard-headed arrogance

 !!


	


It's not the British bureaucrats. It's the accepted standards of

aeronautical engineering. *EVERY* aeronautical engineer I've ever spoken to

has said that having unbalanced ailerons is not acceptable as a matter of

principle.

-- 

Jay Maynard, K5ZC, PP-ASEL, CFI-SP   http://www.conmicro.com

http://jmaynard.livejournal.com       http://www.tronguy.net

Fairmont, MN (KFRM)                        (Yes, that's me!)

AMD Zodiac CH601XLi N55ZC http://www.tronguy.net/N55ZC.shtml

_________________
Jay Maynard, K5ZC
AMD Zodiac XLi N55ZC

Gig Giacona

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

Posted: Mon Jun 15, 2009 6:36 am Post subject: Re: XL Testing UK

 	  jmaynard wrote: 	
		  On Mon, Jun 15, 2009 at 09:51:11AM -0400, jaybannist(at)cs.com wrote:

There's one thing that the German testing didn't cover: what happens if

there's no tension on the aileron cables? 	


Come on Jay, this one is easy. The airplane becomes uncontrollable and flutter will be the least of your concerns.

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

d.goddard(at)ns.sympatico
Guest

Posted: Mon Jun 15, 2009 7:21 am Post subject: XL Testing UK

I think I recall seeing that they claimed no issue with tensions as low as 

10 lbs. So there appears to be some flexibility there. No tension is so far 

outside the acceptable range that I don't think it should be tested a that 

level.



 	  Quote: 	
		  



 jmaynard wrote:

> On Mon, Jun 15, 2009 at 09:51:11AM -0400, jaybannist(at)cs.com wrote:

> There's one thing that the German testing didn't cover: what happens if

> there's no tension on the aileron cables?

jmaynard

Joined: 27 Feb 2008
Posts: 394
Location: Fairmont, MN (FRM)

Posted: Mon Jun 15, 2009 7:39 am Post subject: XL Testing UK

On Mon, Jun 15, 2009 at 12:19:54PM -0300, Dave wrote:

 	  Quote: 	
		   jmaynard wrote:

> On Mon, Jun 15, 2009 at 09:51:11AM -0400, jaybannist(at)cs.com wrote:

> There's one thing that the German testing didn't cover: what happens if

> there's no tension on the aileron cables?

 I think I recall seeing that they claimed no issue with tensions as low as 

 10 lbs. So there appears to be some flexibility there. No tension is so far 

 outside the acceptable range that I don't think it should be tested a that 

 level.


	


Actually, they tested down to 5 pounds. I agree that slack cables are a

problem in other ways - but then, take a look at what happened when they

examined the Dutch Zodiac fleet: over half of the airplanes had them.



Even so, if every aeronautical engineering reference says that unbalanced

ailerons aren't acecptable, how can we complain when a regulatory authority

takes them at their word?

-- 

Jay Maynard, K5ZC, PP-ASEL, CFI-SP   http://www.conmicro.com

http://jmaynard.livejournal.com       http://www.tronguy.net

Fairmont, MN (KFRM)                        (Yes, that's me!)

AMD Zodiac CH601XLi N55ZC http://www.tronguy.net/N55ZC.shtml

_________________
Jay Maynard, K5ZC
AMD Zodiac XLi N55ZC

aerobat

Joined: 07 Nov 2008
Posts: 21
Location: UK

Posted: Mon Jun 15, 2009 8:55 am Post subject: Re: XL Testing UK

Did the Germans test at their max weight of 450kg or higher weights as in UK and US. It could make a difference !

Gig Giacona

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

Posted: Mon Jun 15, 2009 10:18 am Post subject: Re: XL Testing UK

 	  aerobat wrote: 	
		  Did the Germans test at their max weight of 450kg or higher weights as in UK and US. It could make a difference ! 	




As far as flutter is concerned it really shouldn't make any difference.

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

jonaburns

Joined: 23 May 2007
Posts: 32

Posted: Mon Jun 15, 2009 10:33 am Post subject: Re: XL Testing UK

Jay,



You say that *EVERY* Aeronautical Engineer states this is unacceptable...



Isn't CH an Aeronautical Engineer?  



Has *EVERY* Engineer you have talked to designed and flown MORE aircraft than CH?



Many of us still question your "Experts" who continue to support speculation and refuse to admit they were WRONG on the Flutter issue, and WILL NOT release their so called engineering for independent review.



There may be an issue, and there may not be.  Everyone should be free to decide their own risk level and you and I have obviously decided differently.  Until there is hard proof that there is an issue we will continue to agree to disagree.  



There are a few that won't accept anything but a design flaw and will do anything they can to fulfill that assumption.  

To those calling Scott crazy and reckless because he chooses to fly his airplane because of blind belief in a government agency is beyond me.  I guess we all need faith in something.  



We all know that government agencies are without flaw or political motivation, right?



Calling an unfinished plane "grounded" is another issue I have.   It isn't "Grounded" it is abandoned.   If it isn't legal to fly, it isn't an aircraft yet, and can't be grounded. Your choice of not finishing the build is your own, just like hundreds of other kits wasting away in attics, basements, and hangers.   

My kids have a "grounded" space ship out back...  It has the best avionics the Home Depot can offer.  The stickers have stayed on for 3 years.





Jon Burns

sabrina

Joined: 15 Jun 2009
Posts: 170

Posted: Mon Jun 15, 2009 11:16 am Post subject: Re: XL Testing UK

Do Not Archive

Last edited by sabrina on Thu Jul 02, 2009 3:53 pm; edited 1 time in total

psm(at)att.net
Guest

Posted: Mon Jun 15, 2009 11:55 am Post subject: XL Testing UK

Welcome back Sabrina!  I am delighted to hear 

from you again.  I was worried you were gone for good.



Of course I would like to meet you (with 

appropriate chaperone) when you visit Washington 

State.  Just let me know where and when.  I don't 

think I am ready to fly my XL but I have another 

(even nicer) plane at my disposal for the next 

year.  I would be happy to fly anywhere in the 

state to meet you.  I am all current and legal, 

so I could take you up if you want.  The plane 

looks a lot like a 150 but performs somewhere between a 172 and 182.



I'll have to consider the name, St. Pauli Girl, 

before agreeing.  If I wind up selling it I 

shouldn't name it.  I don't think anyone will pay 

a fair price, but I feel I have already received 

my money's worth on the airframe.  Four years of 

great activity is worth a lot to me.  On the 

other hand, I have a very nice engine and 

avionics that many builders wouldn't pay the 

price for.  I'm not going to give them away to 

anyone (except perhaps someone I really like) 

just because I am reluctant to fly the plane.  I 

am considering building another airframe that can 

use the same engine and avionics.



I, for one, never thought you were responsible 

for any of the flaming that goes on regularly 

here.  I am afraid I can't say the same about 

myself.  I try to be "Professional" and stay away 

from personal attacks, but there are many here who don't see it the same way.



Paul

Camas, WA (1W1)

do not archive





At 12:16 PM 6/15/2009, you wrote:

 	  Quote: 	
		  



I'm back...



I just wanted to make sure it was not me who was 

causing the list to flame.   It can flame very well on its own.



I just finished my 2,000th consecutive day of 

school without being sick, absent or tardy.  My 

U.S. Student pilot certificate issued June 3d 

and my IL motorbike permit issued that same 

day.   I just finished with the ACT this 

Saturday and the SAT the Saturday before 

that.   No scores on those yet.   I did score a 

perfect 800 on the May 2d SAT Subject Test: Math 

Level 2.   I have been riding side by side with 

my dad on my motorcycles the past weekâ€”really 

cool!   I take the M permit course this 

week.  If I pass, the Secretary of State may 

issue an M permit next week.   Until then, I 

ride my 16th birthday present:  a 1985 Honda CB125S...



Paul, I will be in Washington State next month, 

what do you say we get St. Pauli Girl in the 

air?   (Hope you don't mind me naming her for you.)

bryanmmartin

Joined: 10 Jan 2006
Posts: 1018

Posted: Mon Jun 15, 2009 3:05 pm Post subject: XL Testing UK

I believe there are a few standard category aircraft that don't have  

balanced ailerons. These are mostly vintage airplanes with a  

relatively low value for Vne. For these airplanes it was considered  

acceptable not to have balanced ailerons. I am not familiar with any  

of these aircraft types, but I have heard of them. I can't cite any  

specific examples. Maybe someone else can? I seem to recall mention  

that some early Cubs were designed that way.

On Jun 15, 2009, at 2:33 PM, jonaburns wrote:



 	  Quote: 	
		   



 Jay,



 You say that *EVERY* Aeronautical Engineer states this is  

 unacceptable...



 Isn't CH an Aeronautical Engineer?



 Has *EVERY* Engineer you have talked to designed and flown MORE  

 aircraft than CH?



 Many of us still question your "Experts" who continue to support  

 speculation and refuse to admit they were WRONG on the Flutter  

 issue, and WILL NOT release their so called engineering for  

 independent review.




	


-- 

Bryan Martin

N61BM, CH 601 XL,

RAM Subaru, Stratus redrive.

do not archive.

_________________
--
Bryan Martin
N61BM, CH 601 XL, Stratus Subaru.
do not archive.

z601(at)anemicaardvark.co
Guest

Posted: Mon Jun 15, 2009 3:53 pm Post subject: XL Testing UK

On Monday 15 June 2009 17:59, Bryan Martin wrote:

 	  Quote: 	
		   



 I believe there are a few standard category aircraft that don't have

 balanced ailerons. These are mostly vintage airplanes with a

 relatively low value for Vne. For these airplanes it was considered

 acceptable not to have balanced ailerons. I am not familiar with any

 of these aircraft types, but I have heard of them. I can't cite any

 specific examples. Maybe someone else can? I seem to recall mention

 that some early Cubs were designed that way.


	


I think all the J3s were built thus. I know that the Short  Wing Pipers 

(Vagabond, Clipper, Pacer, TriPacer, and Colt) did not have balanced 

ailerons. The TriPacer flies at about the same speed as the 601XL, but I am 

unaware of any flutter incidents with one that was properly maintained.



-- 

=============================================

                Do not archive.

=============================================

                Jim B Belcher

    BS, MS Physics, Math, Computer Science

                  A&P/IA

     Retired aerospace technical manager

=============================================

grs-pms(at)comcast.net
Guest

Posted: Mon Jun 15, 2009 5:03 pm Post subject: XL Testing UK

As I noted a few weeks ago, The Ercoupe is one vintage airplane on which 

aileron balance weights were not required.  They were initially fitted but 

subsequent analysis and testing showed that they were not needed and the 

factory recommended their removal.  These Ercoupes had fabric-covered wings. 

(Some later Ercoupes were produced with metal covering the same basic 

structure.) The metal covered leading edge was not a D-tube structure: i.e. 

the metal was not attached to the lower chord of the main spar.  Torsional 

stiffness of the wing was realized by a system of diagonal ribs.  I believe 

Vne was 146 mph, but it's been a long time since I flew one so that may be 

wrong.



George Swinford



Do not archive





---

Juan Vega Jr

Joined: 13 Jan 2009
Posts: 157

Posted: Mon Jun 15, 2009 5:52 pm Post subject: XL Testing UK

check the -

Piper cub

cessna 140 and 150

Erocoupe

Taylor craft

sopwith Pup

Tiger Moth

stinson

--

Juan Vega Jr

Joined: 13 Jan 2009
Posts: 157

Posted: Mon Jun 15, 2009 5:52 pm Post subject: XL Testing UK

check the -

Piper cub

cessna 140 and 150

Erocoupe

Taylor craft

sopwith Pup

Tiger Moth

stinson

--

Tim Juhl

Joined: 21 Mar 2006
Posts: 488
Location: "Thumb" of Michigan

Posted: Mon Jun 15, 2009 7:28 pm Post subject: Re: XL Testing UK

My Champ does not have balanced ailerons.  My buddy just built a 80% replica of a Tiger Moth - it doesn't have balanced ailerons either.



Tim

_________________
______________
CFII
Champ L16A flying
Zodiac XL - Jabiru 3300A
Almost done! It'll fly in spring!

n801bh(at)netzero.com
Guest

Posted: Mon Jun 15, 2009 7:43 pm Post subject: XL Testing UK

Subsequent analysis and testing proved deadly for these two guys.

http://www.ntsb.gov/ntsb/brief.asp?ev_id=20081213X62443&key=1

Ben Haas

N801BH

www.haaspowerair.com



--------

grs-pms(at)comcast.net
Guest

Posted: Mon Jun 15, 2009 8:27 pm Post subject: XL Testing UK

Something did.  I doubt it was "analysis and  testing".  There is a history of intergranular corrosion of Ercoupe  wing attach fittings, leading to failure and wing separation.  As for  the  observed fluttering, that may or may not have been an accurate  observation. Failure analysis of the wreckage should determine that one way  or the other.

  

 I had the sad experience of witnessing a fatal in-flight  breakup.  My observations did not agree in all respects with the eyewitness  who was standing right beside me.  I now take eyewitness  observations, my own included, with a grain of salt. 

  

 George

  

 do not archive

 [quote]   ---

s.clive.richards(at)homec
Guest

Posted: Tue Jun 16, 2009 1:53 am Post subject: XL Testing UK

[quote]      

JAY<?xml:namespace prefix = o ns =    "urn:schemas-microsoft-com:office:office" />   

                  The request for a design modification was made by the LAA engineers who have    to issue Permits to fly on behalf of our CAA (not British CAA Bureaucrats, ) before the German tests were    completed. These things take time as engineering resources are limited    & the home builder had to carry out the work.   

                Some builders on the list were asking for a zenith designed mod so a tested    one will be available if tests are successful    

 As you are experimental in    US it will be up to you if you carry the work out, in UK it will probably be    mandatory but XLs will be then be released to fly.   

Clive   

                G-CBDG 305 hrs 601HD not affected by above but it flys much slower.   

    

 

   ---

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