The reassembly of my 54'C180 is advancing ...
It was one year ago today that a twister flipped my aircraft while moored to anchor on floats. Having owned my 180 for 38 years, I could not let it go ... Hence this 1000 man hour extensive refurb.
The rigging of flight controls is on for this weekend, the tensiometer is ready to go.
An early 180 mentor in the 1970's suggested drooping both the ailerons to neutral 1" below the wing tips for better performance on floats. It has worked well for me in the past ...
Input suggestions on aileron rigging welcome.
Comments on rudder, elevator and flaps also welcome.
Thanks

Remember, however much you droop the ailerons, that much less down deflection is available-- and since they are tied together, that much less up aileron on the opposite side.
If it was my airplane, I'd rig it per the Cessna series 100 manual.
IMHO if drooping ailerons are desired, a R-STOL kit is in order.

TCDS says 20° up, 15° down. I'd ensure that you have the 35° of travel. Check the rigging section in your service manual to see what tolerances are given. You can be at the edge of the tolerance, but I wouldn't stray outside it. A bit of droop may be allowable within the spec, but don't exceed it is my advice. Of course, a bit of drag might not make much difference on a float plane, but be careful. Range and speed will suffer. Loads on the control system will increase. You're messing with every engineering parameter and signing up as a test pilot when you try to outsmart mother Cessna.

Another thing to consider when drooping the ailerons is you can introduce nasty stall characteristics. Most aircraft ( including cessnas ) have washout in the wings. The angle of incidence is decreased further out the wing. There are two reasons for this. 1. Reduces the flight load on the outboard, lighter, weaker part of the wing and more importantly for this discussion, 2. Causes the wing to stall inboard first. This lessens the effect of wing drop and maintains aileron control longer into the stall.
Drooping your aileron has the effect of increasing the angle of incidence on the outboard section of the wing and can turn a docile stalling wing into one the is downright nasty.

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Try it and see for yourself. I've never had one that wasn't drooped some. Still here to tell about it.

Rigging by the book is always the safest way to go, But after 50 years around and in the skydiving business I have learned a few things about rigging a Cessna for best possible climb rate. Drooping the ailerons a few degrees will increase climb rate and decrease cruise speed. Getting the angle of incident set correctly for your mission will also help. Just remember cruise speeds will always be compromised to gain extra lift.

gbflyer wrote:Try it and see for yourself. I've never had one that wasn't drooped some. Still here to tell about it.

It was explained to me by a very high time, highly experienced and well respected ag pilot that many years ago there was an abnormally high incidence of pawnees spinning in. Investigation uncovered that most guys were drooping the ailerons to improve takeoff and climb performance or generally get more lift out of the wing. This was blamed for the nasty stall/ spin.

I've no doubt you can get more out of a plane with certain tweaks here and there. I've done it plenty myself over the years. I just wanted to share this so that when someone reads this thread and thinks about messing with their rigging, if they don't know what they're doing, maybe they'll think twice or at least be aware that little changes can have big consequences.

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hotrod180 wrote:Remember, however much you droop the ailerons, that much less down deflection is available-- and since they are tied together, that much less up aileron on the opposite side

Don't mean to be pedantic, but not so... TOTAL aileron travel on all Cessna singles is fixed. The aileron bellcrank has fixed length slot with a bolt and bush running through it and providing cable rigging is correct, the bolt/bush limits travel at each end of the slot. If, for some unknown reason, you wanted to deviate from Cessna's published data and the TCDS, you could droop the ailerons by lengthening the pushrod from the aileron to the bellcrank, ensuring the rod ends remain safe, ie sufficient thread engaged... Cessna made a fairly wise decision to build in washout to help the stall characteristics, drooping the ailerons will change the overall washout and may adversely affect stalls... I'm no aerodynamics expert, but there's a flappy thing just inboard of the aileron that could be drooped as well, maybe this would maintain the overall washout.. It's not uncommon to see a Cessna single with poorly rigged ailerons and flaps, be it drooped or reflexed. These ones can sometimes be identified by climbing a little better or cruising a little faster than one with correctly rigged ailerons and flaps... My planes are far more capable than I am, so things like this wouldn't help me, I just recommend following the manual.

+1

onefitty wrote:.... If, for some unknown reason, you wanted to deviate from Cessna's published data and the TCDS, you could droop the ailerons by lengthening the pushrod from the aileron to the bellcrank, ensuring the rod ends remain safe, ie sufficient thread engaged....

Sure that'd work... the down aileron would be farther down, but wouldn't the up aileron also be more down?
I'm no engineer, so I think I'll stick to factory rigging specs on mine.

Yes, that's correct, but you still have the same amount of travel overall, just altering the neutral position... I've heard it may increase adverse yaw, but the rudder seems quite useful in that regard..

I would just make sure that when you do lengthen the rod to get the droop you want, make sure the rod doesn't contact the aileron. Its pretty close, and I have seen where guys have re skinned the ailerons with skins that don't have the relieved area and the rod makes contact at full deflection.