  | 
				Matronics Email Lists Web Forum Interface to the Matronics Email Lists   
				 | 
			 
		 
		 
	
		| View previous topic :: View next topic   | 
	 
	
	
		| Author | 
		Message | 
	 
	
		chris Sinfield
 
 
  Joined: 28 Nov 2006 Posts: 270 Location: Sydney Australia
  | 
		
			
				 Posted: Sat Sep 12, 2009 2:27 am    Post subject: Cof G - weight and balance | 
				     | 
			 
			
				
  | 
			 
			
				OK 
 I am thinking of the  C of G movement aft on the envelope
 
 Why does the fwd line move aft of 18% when above 1080lb up to 23.3% at 1320lb? what causes that?
 
 Chris..
 
  |  | - The Matronics Zenith601-List Email Forum - |  |   |  Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
 
  http://www.matronics.com/Navigator?Zenith601-List |  
  |  
 
 
 
  
 | 
			 
		  | 
	 
	
		| Back to top | 
		 | 
	 
	
		  | 
	 
	
		bryanmmartin
 
 
  Joined: 10 Jan 2006 Posts: 1018
 
  | 
		
			
				 Posted: Sat Sep 12, 2009 6:45 am    Post subject: Cof G - weight and balance | 
				     | 
			 
			
				
  | 
			 
			
				Probably because you might not have enough margin in elevator  
 authority in the region forward of that line. The higher the weight  
 and more forward the CG, the more elevator is needed to keep the nose  
 up.
 
 On Sep 12, 2009, at 6:27 AM, chris Sinfield wrote:
 
  	  | Quote: | 	 		   
  >
 
  OK
  I am thinking of the  C of G movement aft on the envelope
 
  Why does the fwd line move aft of 18% when above 1080lb up to 23.3%  
  at 1320lb? what causes that?
 
  Chris..
 
 | 	  
 -- 
 Bryan Martin
 N61BM, CH 601 XL,
 RAM Subaru, Stratus redrive.
 do not archive.
 
  |  | - The Matronics Zenith601-List Email Forum - |  |   |  Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
 
  http://www.matronics.com/Navigator?Zenith601-List |  
  |  
 
 
 
  
 _________________ -- 
 
Bryan Martin
 
N61BM, CH 601 XL, Stratus Subaru.
 
do not archive. | 
			 
		  | 
	 
	
		| Back to top | 
		 | 
	 
	
		  | 
	 
	
		chris Sinfield
 
 
  Joined: 28 Nov 2006 Posts: 270 Location: Sydney Australia
  | 
		
			
				 Posted: Sun Sep 13, 2009 12:49 pm    Post subject: Re: Cof G - weight and balance | 
				     | 
			 
			
				
  | 
			 
			
				Thanks Bryan
 not many others responded with the answer, I wonder if they all have this reduction in C of G range in their flight manuals.. 
 
 Maybe someone going to the Zenith get together could ask Seb?
 Chris
 
  |  | - The Matronics Zenith601-List Email Forum - |  |   |  Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
 
  http://www.matronics.com/Navigator?Zenith601-List |  
  |  
 
 
 
  
 | 
			 
		  | 
	 
	
		| Back to top | 
		 | 
	 
	
		  | 
	 
	
		Terry Phillips
 
  
  Joined: 11 Jan 2006 Posts: 346 Location: Corvallis, MT
  | 
		
			
				 Posted: Sun Sep 13, 2009 6:20 pm    Post subject: Cof G - weight and balance | 
				     | 
			 
			
				
  | 
			 
			
				Chris
 
 You raise an interesting point. The situation is bit more complex than a 
 simple reduction in CG range. A year ago, I found a W&B data sheet on 
 zenithair.com, called wb-xl-new.pdf, with the date 1/02 on it. I can no 
 longer find that document on the site. Of course that doesn't mean it's not 
 there. There's lots of stuff that I can't find on that site.
 
 The 1st attached jpg shows a figure from that pdf.
 
 Within that past year, I found an AMD POH dated 12/05 on the net which 
 contained that same diagram, see 2nd attach.
 
 Those CG ranges are rectangles 20 to 30% of MAC.
 
 The AMD POH that was referenced in Zodiac Update of 7/27/09, contains the 
 diagram shown in the 3rd attachment. I presume that shows the reduction you 
 are referring to. Looking at the front of the range, one can see that it 
 now extends forward of the former 20% (12 inch) envelope. But at a reduced 
 take-off weight. The reduced take off weight also applies between 12" and 14".
 
 Bryan's explanation sounds plausible. You are right, somebody should ask 
 the Zenair folks what is going on.
 
 Terry
 At 01:49 PM 9/13/2009 -0700, Chris wrote:
  	  | Quote: | 	 		  Thanks Bryan
 not many others responded with the answer, I wonder if they all have this 
 reduction in C of G range in their flight manuals..
 
 Maybe someone going to the Zenith get together could ask Seb?
 Chris
 
 | 	  
 
  	  | Quote: | 	 		  >
 >
 >Probably because you might not have enough margin in elevator
 >authority in the region forward of that line. The higher the weight
 >and more forward the CG, the more elevator is needed to keep the nose
 >up.
 
 | 	  
 
 Terry Phillips  ZBAGer
 ttp44~at~rkymtn.net
 Corvallis MT
 601XL/Jab 3300 s .. l .. o .. o .. w build kit - Tail, flaps, & ailerons 
 are done; waiting on the wings
 http://www.mykitlog.com/N47TP/
 
  |  | - The Matronics Zenith601-List Email Forum - |  |   |  Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
 
  http://www.matronics.com/Navigator?Zenith601-List |  
  |  
 
 
 
  
	
  
	 
	
	
		
	 
	
		|  Description: | 
		
			
		 | 
	 
	
		|  Filesize: | 
		 81.97 KB | 
	 
	
		|  Viewed: | 
		 4610 Time(s) | 
	 
	
		
  
 
  | 
	 
	 
	 
	 
	
	
		
	 
	
		|  Description: | 
		
			
		 | 
	 
	
		|  Filesize: | 
		 59.5 KB | 
	 
	
		|  Viewed: | 
		 4610 Time(s) | 
	 
	
		
  
 
  | 
	 
	 
	 
	 
	
	
		
	 
	
		|  Description: | 
		
			
		 | 
	 
	
		|  Filesize: | 
		 44.36 KB | 
	 
	
		|  Viewed: | 
		 4610 Time(s) | 
	 
	
		
  
 
  | 
	 
	 
	 
 _________________ Terry Phillips
 
Corvallis, MT
 
ttp44<at>rkymtn.net
 
Zenith 601XL/Jab 3300 slow build kit - Tail feathers done; working on the wings. | 
			 
		  | 
	 
	
		| Back to top | 
		 | 
	 
	
		  | 
	 
	
		chris Sinfield
 
 
  Joined: 28 Nov 2006 Posts: 270 Location: Sydney Australia
  | 
		
			
				 Posted: Sun Sep 13, 2009 8:03 pm    Post subject: Re: Cof G - weight and balance | 
				     | 
			 
			
				
  | 
			 
			
				Spot on the money Terry
 I wonder what gives.???
 I have the older W&B forms as well and that is why I am asking about the changes..
 
 Someone must know the reasons why the change in the AMD manual, how about all you AMD owners, what did they tell you ???
 Chris
 
  |  | - The Matronics Zenith601-List Email Forum - |  |   |  Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
 
  http://www.matronics.com/Navigator?Zenith601-List |  
  |  
 
 
 
  
 | 
			 
		  | 
	 
	
		| Back to top | 
		 | 
	 
	
		  | 
	 
	
		Doug.Norman(at)sportaviat Guest
 
 
 
 
 
  | 
		
			
				 Posted: Mon Sep 14, 2009 12:11 am    Post subject: Cof G - weight and balance | 
				     | 
			 
			
				
  | 
			 
			
				As explained in a previous response, it has to do with elevator authority at
 slower speeds during TO&L. Remember that the AMD airplanes use the O-200a
 engine which is fairly nose heavy.
 Doug
 AMD CH601XL N601DN
 
 --
 
  |  | - The Matronics Zenith601-List Email Forum - |  |   |  Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
 
  http://www.matronics.com/Navigator?Zenith601-List |  
  |  
 
 
 
  
 | 
			 
		  | 
	 
	
		| Back to top | 
		 | 
	 
	
		  | 
	 
	
		 | 
	 
 
  
	 
	    
	   | 
	
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum You cannot attach files in this forum You can download files in this forum
  | 
   
 
  
Powered by phpBB © 2001, 2005 phpBB Group
  
		 |