Yeah MAte thanks for this it will come in handy building and flying keeping in touch etc...... Going flying this morning I hope weather depending

Yeah mate replied today.. Sorry been flying instead of in front of the computer

down to Jabiru or corvair on price I am still waiting on a few things to happen we will see soon and i havent looked at the latch as yet

cheers Kevin

Hi Phill
hows building going
they fly great i;m loving it but dont have enough time
regards Paul

I like that prop ;
let me know how it goes

I will e-mail you the pushrod pixs.

Hi Phill,

Being faced with the flutter problem issue as many are, I was very pleased to see the photos of the push rod system. Unfortunately I was unable to find the photos of the Brazil XL with the aileron counter weights. Could you e-mail them to me or repost them. It would be very greatly appreciated.
Thanks,
Jim Timm

Hi Phill,

During construction, I was initially a bit concerned that the ailerons were not balanced, but decided that because the design has been flying for some time without a problem, perhaps my concerns are unfounded. Well I guess I was wrong in view of passing events. I suspect because fairleads are used in the system rather than a pulley, keeping adequate tension on the cables introduces sufficient damping friction and the higher cable tension also increases the resonant frequency of the system sufficiently to reduce the flutter potential. Relying on cable tension alone does not seem to me to be a very reliable/suitable solution to the problem. As I recall, the aileron bellcrank rib was relative ridge and should not contribute to the problem. I must take another look at it. Be aware, when new cable is installed, initially there can be a small amount of apparent "stretch" as the cable strands come into conformity. After a short period of use and resetting the tension the cable tension should not change significantly. I have slightly over 150 hrs flight time on the airplane and had on one occasion slightly flown over Vne without ever experiencing any indication of the onset of flutter. A friend has flown his almost 500 hours, and in hot Phoenix summer turbulence, without indications of a problem.

Hi Phil,

Ross jsut called and said somehting about not mass balancing?
I am proceeding with this as a next sttep based on information from Tony Bingellis.

What have you heard

Cheers
Eddie

Hi Phill,

I must apologize for not answering your questions in your previous post more directly.

In my opinion I think the present control system, given the right conditions, could be susceptible to aerodynamic flutter with possibly catastrophic results.

I, like others, do not believe cable tension alone is a satisfactory solution to the potential problem.

I have not noticed an indication of flutter onset flying in significant turbulence or over the operating speed range.

Using an aircraft cable tensiometer, my control cables were initially installed and maintained at the drawing specified tension of 30 ± 5 pounds. For the near future, I plan on maintaining a 30 to 35 lb tension.

I think the aileron bellcrank rib is sufficiently ridgid enough to sustain the reqd tension loads.


I checked out your web page and I like the 650 canopy structure idea.

This comment is a bit late I suspect, but I had an initial weight and balance issue. With no nose wheel, the CG was a bit too far aft at no fuel. Moving things around it finally came in. After painting my empty weight is 758 lbs.

Regards,
Jim Timm

Hi Phil,

Zenith has instigated a Ground Vibration Test in Germany I believe, this data will be used as an input to the flutter analysis done by one or more engineers to identify if there is a real flutter problem and then of course hwo to deal with it. There is a utube video of the test setup linked tot eh man Zenith site.

Cheers
Eddie

Hi Phil,

Here is the link to the vibration testing;

CH650E: Flutter - Ground Vibration Tests ... Zodiac CH650E
www.youtube.com/watch?v=0VMMVuVrweM

And yes all control surface on the RV are mass balanced.

Cheers
Eddie