Rudder Counterweight
Moderators: GAHorn, Karl Towle, Bruce Fenstermacher
Rudder Counterweight
Any one out there have any experience re-attaching a rudder counter weight?
There are two common ways to attach elevator and rudder balance weights. Originally the factory used "cherry max" type self-locking rivets (CR163C-4-2 and CR163C-4-8's), also known as NAS445 types. These are the same type rivets that hold the leading edge onto the rudder, and if well done can double-duty to hold the weight.
But most repairs to rudders/elevators weights simply used a couple of #8 X 7/8" PK sheet metal screws.
Either fastener goes through the end-rib or tip-rib and into the weight. (The head of the fastener lives in the airspace between the counterweight "horn" and the stabilizer. Be careful no interference exists to control movement.)
As a matter of interest, many pilots overlook the necessity to inspect the security of those weights on each preflight. Make it a regular habit, not only to avoid a loose weight, but also to avoid a protruding fastener from interfereing with control surface movement when the fastener backs out and interferes with the stabilizers. (It'll lock up the rudder and/or elevators.)
But most repairs to rudders/elevators weights simply used a couple of #8 X 7/8" PK sheet metal screws.
Either fastener goes through the end-rib or tip-rib and into the weight. (The head of the fastener lives in the airspace between the counterweight "horn" and the stabilizer. Be careful no interference exists to control movement.)
As a matter of interest, many pilots overlook the necessity to inspect the security of those weights on each preflight. Make it a regular habit, not only to avoid a loose weight, but also to avoid a protruding fastener from interfereing with control surface movement when the fastener backs out and interferes with the stabilizers. (It'll lock up the rudder and/or elevators.)
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
- Squirrly 170B
- Posts: 2
- Joined: Fri Sep 08, 2023 6:56 pm
Re: Rudder Counterweight
Are there any updates or pictures of this procedure? I just finished installing lower rudder skins and a new bellcrank. I am now 10 OZ underweigh at 27 inches and will have to open the horn to install the weight. I think this might loosen the factory installed 4 lb weight. Any ideas would be grateful.
Re: Rudder Counterweight
Here’s what the balance weight looks like from the inside of the rudder horn. Just FYI, since most people have never seen it.
Re: Rudder Counterweight
I could be wrong, but I don't remember ever having to add that much weight to a rudder that wasn't heavily modified. Is this rudder stripped or painted? Are you certain the math is correct?
Re: Rudder Counterweight
Cessnut, how many have you balanced and what do you normally find?
Re: Rudder Counterweight
I have not balanced many 170 rudders, although I will be doing 2 soon. However, I have balanced many Cessna rudders ranging from 150s through 208s. Like I said, I could very well be wrong. 10 oz. at the balance weight would be approximately 8 in. lbs. That would mean it is +35. Seems like a lot.