Rigging Question

Post by **GAHorn** » Wed Nov 01, 2006 5:17 am

tshort wrote:...I have wondered about mine, too - no heavy wing, but when in level cruise the elevator is deflected downward a significant amount...Thomas

The center-of-gravity of your aircraft will change depending upon how you have loaded it. This will directly affect the position of a trimmed elevator (which in turn is also affected by the speed to which it is trimmed.)

(Sounds as if your elevator is like the rest of the fleet.)

wa4jr · Post by **wa4jr** » Thu Nov 02, 2006 2:56 am

Thanks for the CPA list of riggers, Tom. Turns out one is in Manassas, VA which is within 30 minutes flying time. With the storm flip and subsequent rebuild of the outboard sections of both wings back in 1962, and years of misadjustment, my plane needs to be taken back to square one and done all over again. Last year at annual my mechanic recommend I droop the left flap to give the left wing more lift since there is no more adjustment room left on the eccentric...but this only helped with flaps at 10 degrees. I suppose I could always slow to 100 and extend the flaps a notch if I need to read my charts with two hands

I"ll make the call tomorrow and set something up with the CPA rigger in Manassas.

Dward · Post by **Dward** » Thu Nov 02, 2006 10:30 pm

Is there any chance y'all could post that list. I happen to be one of those poor misguided individuals with an oh so embarrassing tab on my aileron

.

Come to think of it I guess it's the plane thats misguided.

Fri Nov 03, 2006 12:29 am

Not sure how appropriate posting a Cessna Pilots Association list would be at The International Cessna 170 Association forum.

I'm proud of my trim tab.

It happens to be one of those legal STC'd electronic ones though. (Don't get one they don't work on the 170 IMO)

Dward · Post by **Dward** » Fri Nov 03, 2006 7:16 pm

Bruce, unless it's copywrited (is that a word?) I don't see a problem. It would sure be of interest to all. If it's because I'm not a CPA member then I guess I'll just have to fly in circles cause 4 memberships is enough for a "just for fun pilot".

Fri Nov 03, 2006 11:09 pm

No Dave I don't care if the list is poster here but the CPA might. I think that's the kind of stuff you get for membership over there. I'm not a member of the CPA so I don't really know.

tshort · Post by **tshort** » Sat Nov 04, 2006 3:19 am

I am a member.
It is on the public portion of their web page.
Trust me, stuff that is not public is password protected.

It is too bad people get so bent out of shape (not saying you are) about some of this information. It is just a list of names / numbers - what is the big deal in giving it to someone to help out with their airplane? I wouldn't feel bad about sharing it if it was behind the members section ... maybe that is wrong, but I would think it was wrong to not make it public (I was actually surprised that it was on the public part of the web page!

)

Thomas

blueldr · Post by **blueldr** » Sat Nov 04, 2006 3:52 am

The easiest way, by far, to check the function of the rudder return springs
is to neutralize the rudder, then reach in on the left side and pull back on the rudder pedals. If they have tension and return toward the firewall when released, the springs are intact.

Post by **GAHorn** » Sat Nov 04, 2006 6:10 pm

The list of CPA "approved" riggers is a common discussion item, in my opinion, and as long as the list is described as originating with CPA I don't see a problem with talking about it or displaying it here. (Do not simply cut-and-paste, however. Whenever quoting someone else's work product, give them credit and do not wholesale copy their work. Short references and info is permissible.)

Anyone wishing information on membership at CPA may contact them at:
P.O. Box 5817, Santa Maria, CA 93456
Phone 805/922-2580 800/343-6416 Fax 805/922-7249
Internet: http://www.cessna.org
E-Mail: cpa@cessna.org

I have a copy of CPA's excellent article on rigging by John Frank and will happily share it on an individual basis. It does not apply specifically to 170's but to Cessna's in general.
Tom Hall (my predecessor) has written about rigging Cessna 170's and submitted it to me, and after a bit of massaging/editing, it will be included in the upcoming Service Manual, and will be a free handout at next year's Galveston Convention to anyone attending.

wa4jr · Post by **wa4jr** » Sun Nov 05, 2006 12:28 am

Hey guys...what's all the fuss with the CPA riggers list? The link to the list was posted on Tom Short's post on the first page of this thread

Post by **Bruce Fenstermacher** » Sun Nov 05, 2006 2:07 am

John

There is really no fuss. It was suggested the list be published here and not knowing how sensitive the CPA might be about someone taking their list I suggested maybe we shouldn't post the list.

I know if the shoe was on the other foot TICA170 might be a little testy. This type of information is one of the things that draws membership to both organizations. If it's posted for all it might be one less reason to be a member of that organization.

In this case the CPA has made the list public on their site. Tom linked to it and all is well.

Really.

Dward · Post by **Dward** » Mon Nov 06, 2006 4:07 pm

Bruce, I reread my post and it sounded a little flippant. It wasn't intended that way and I hope you didn't take offense and if anyone tries to sell me an electric aileron trim I'll decline.

Now back to the original thread. My eccentrics are adjusted all the way out and my right wing is still heavy. What should I look at first? Maybe I just need to trade a wing with someone who is heavy on the left.

Post by **GAHorn** » Mon Nov 06, 2006 7:14 pm

Dward wrote:Bruce, I reread my post and it sounded a little flippant. It wasn't intended that way and I hope you didn't take offense and if anyone tries to sell me an electric aileron trim I'll decline.

Now back to the original thread. My eccentrics are adjusted all the way out and my right wing is still heavy. What should I look at first? Maybe I just need to trade a wing with someone who is heavy on the left.

Looking at something "first" may be misleading. The best probable solution is to start all over "first". (A mis-rigged airplane is most likely the result of a previous error and a mis-guided attempt to cover up the error. Any subsequent attempt to re-rig another portion of the airplane only continues to "hide" the original defect. One error builds on another. The error can be previous mis-rigging, or improper/incorrect repair. Only by starting with a completely new re-rigging will it be likely to discover the problem and correct it properly. IMHO. )

c170b53 · Post by **c170b53** » Mon Nov 06, 2006 8:02 pm

Just my opinion: To be clear as to your set-up. The L/H and R/H ailerons are correctly rigged to neutral. Easy to check with rig pins whether your surfaces are at neutral and the cables are correctly rigged. The flaps are both fully retracted against the wing trailing edge. The rudder should be checked to ensure it is in a neutral position (ensure tail wheel off ground when checking)and the trim tab is at neutral. If these checks have been confirmed. Then it's eccentric time, generally a small adjustment is needed as neutral can be hard to perceive when you're close. Yours has the right wing Trailing edge adjusted full down. The left wing T/E has been adjusted full up and if the wing is still heavy after the checks then (and this is only me) I would weigh the amount of aileron control input required to level the wings against the amout of Yaw induced by picking up the heavy wing with the rudder tab. The problem of course is by adjusting your eccentrics to the opposite limits and bending your rudder tab to correct for a heavy wing you now have an aircraft that is unlikely to stall straight forward.

Mon Nov 06, 2006 10:28 pm

George I agree with your last post BUT knowing your aircraft setup and just reviewing the basics before making any trim adjustments doesn't hurt.

For example one could look at the rudder return springs, rudder and rudder trim for any anomalies that would lead someone to incorrectly adjust the wing eccentrics. Correcting a rudder situation might then lead to centering the wing eccentrics.

With my airplane the wing eccentrics were also adjusted to the max for a left heavy wing. After centering them I found the wing was no heavier but the airplane went faster.

After reviewing the big picture, I starting with the turn and slip indicator moving to the rudder then the wings, flaps and ailerons. I checked all rigging to find it all fairly close. I suspect that sloppy repairs to the left wing aileron and flap are causing the heavy wing more than anything so I compromised and just slightly lowered the left aileron and flap leaving the wing eccentrics neutral. My plane is faster and the wing isn't as heavy. I just put more gas in the right wing.