Grounded again

[Paul]

Hey Bill.
Thanks for the cautionary note re the jury strut attachments. Never a bad thing to get focused on aspects of our pre-flight.
I have to put in my $0.02 worth on the notion that our Carbon Cubs are fragile. I flew my EX for the first time this past January, 2015. Since then I've logged almost 200 hours. I had only 20 tailwheel hours prior to flying my CCEX so this plane has seen me through much of my learning curve.
Over the past 12 months I've landed my CC over 425 times (calling some of those a landing is a stretch ;-). Over half of those landings have been on dirt and grass strips in AZ, UT, ID, MT, NM, CO, NE, SD and Alberta, Canada. The strips in around Johnson Creek, ID and Mack Mesa, CO were amazing and the roughest stuff I've ever set down on. Not saying any of this to feather my cap rather to give a shout out for a tough and durable backcountry aircraft that's taken real good care of me through the most enjoyable year of aviating in my 35 years of flying (without a single broken part or breakdown}.
Happy New Year everyone!
Paul

Cubcrafters CCEX
N224Y
Cirrus SR22
N5123Y

[seastar]

Bill

[cityrancher]

Bill,
I think we understand your frustration. I have had similar feelings over the years regarding SB's that were in my mind questionable. To make a blanket statement about the integrity of the aircraft in light of the combined experience of the group and then attack responders is not enhancing your position. You have been in aviation long enough to know how it works. If you are truly suspect of the aircraft's design, it may not be the plane for you.
Hope the New Year finds you happy.

[seastar]

Cityrancher
You are absolutely correct.
Bitching on this forum does me no good and irritates those who love their Cabon Cubs.
I love the performance as much as anyone else.
My problem are the things that have broken or failed.
I think you are correct, it may be the wrong plane for me.
I guess I will just have to fix what breaks or sell it.
i did not intend to attack/irritate you or anyone else and apologize if I did.
I'll stay off of here from now on.

[turbopilot]

I'll stay off of here from now on.

I hope not. Bill, you have been a valuable resource on the forum. Like you I would like to know what is going on with the jury strut issue. The other SB's we have had since 2010 are pretty well explainable. Don't have the same feeling for the failures in the jury strut.

We got our Carbon Cubs about the same time in 2010. I complied with the jury strut SB in my first Carbon Cub. Now on Carbon Cub #2 and have never had a problem with either the old or new fitting. So what is the difference?

I would guess 95%+ of the operating hours in my Carbon Cubs have been at RPM settings between 2050 and 2100 RPM. Never really in a hurry to go anywhere in the CC so I just pull it back to 40% power and enjoy the ride. I often would make small changes to the RPM when I saw the aileron cables vibrating as they ran up the back side of the main strut. I don't like vibration and I was often taking video so I would fine tune the RPM settings to eliminate the vibration in the aileron cables. In doing all that I was obviously reducing vibration in the entire airframe.

The reason I bring this up is that I can recall flying airplanes that had POH limitations operating continuously at certain RPM's. In those aircraft I think the limitations were there to avoid certain resonant frequencies in the propeller which could lead to fatigue.

So back to my previous comment, in doing video work in the CC there are very clearly certain engine RPM's that excite resonant vibrations in the airframe of the Carbon Cub. I spent all of my time in the CC trying to find certain RPM's with the lowest vibrations so I never really noted those RPM's with the highest vibrations. In all of my testing for video 1,800 RPM is one setting I have found to have very little vibration in my two Carbon Cubs.

So do you have a favorite RPM where you typically operate your CC?

[randylervold]

Not sure, but in a positive G condition the lift strut is in tension and the jury strut does nothing but damp vibration.
In a negative G condition the lift strut is under compression and might tend to bend if not restrained by the jury strut.
Under compression the jury strut cuts the "beam length" about in half which, if I remember my mechanics correctly, greatly increases the lift Struts ability to resist bending.
Additionally the combination of the jury struts and the wing ribs along with the brace between the front and rear lift struts forms a strong "box section"at the center of the wings.
I think you could fly the airplane without jury struts if you resisted the temptation to do negative G maneuvers and took great care in landing and avoided rough air. LOL!

Bill

All correct!

[randylervold]

Bitching on this forum does me no good and irritates those who love their Cabon Cubs.
I love the performance as much as anyone else.
My problem are the things that have broken or failed.
I think you are correct, it may be the wrong plane for me.
I guess I will just have to fix what breaks or sell it.
i did not intend to attack/irritate you or anyone else and apologize if I did.
I'll stay off of here from now on.

Bill, I too hope you stick around, you are indeed a valued contributor.

I don't get in here as often as I used to so I'd like to sound off a bit, if you don't mind, with my perspective...

This forum has always been intended as a venue for owners to connect with each other and share information on anything relating to our aircraft, both good and bad. Of course we all have our own opinions and this forum is intended to allow that. My only rules are that no inaccurate information should be disseminated, and no personal attacks should be made. Otherwise we all would like to know what you think, what your perceptions are, and what suggestions you have.

As the person who installed this board shortly after I started at CC in 2009 I am the "Admin" with full privileges to edit/delete/censor any message or thread. In fact in the six years since then I have only removed one sentence from one message which was an unnecessary personal insult to someone. For that, and to all who participate here, THANK YOU!

We at CC haven't figured out how to make a perfect aircraft, yet. But I can assure you we spend each and every day working toward that goal. I am proud of the effort our team here makes, we are getting better all the time in terms of our designs, our team, and our support systems. And with the cooperation of our valuable customers, especially the technically savvy ones such as yourself, we will continue toward that goal for our collective benefit.

Ok, off soapbox now.
Happy New Year to all, and may 2016 bring many joyful flight hours to each of you!