The International Cessna^® 170 Association

Checking my aileron's w/ regard to their positions w/ neutral yoke I find the following:

Left aileron-outboard end @ tip is 1/2" below trailing edge of tip
Left aileron-inboard end @ flap is 1) even if flap at rest or 2) 1/4" to 1/2" down if flap pushed up as it would be in flight.

Right aileron-outboard end @ tip is down by 1/4" to 1/2" below tip trailing edge
Right aileron-inboard end @ flap is 1) up 1/2" if flap at rest or 2) is even if flap is pushed up to as it would be in flight.

Is my rigging off? Bad? In a semi-perfectly rigged plane (using a '56 B model as a guide) where should the aileron ends be in relation to the outboard ends of the flaps and wing tips?

I'm not Brad. (I'm also not Tom Hall, who developed the rigging info for the 170 series). But...

The flaps should be held UP as if in flight.

Adjust the ailerons to a neutral position, by reference to the flaps. This adjustment can be made by disconnecting the aileron push-pull tube from the bell cranks and making the adjustment at the rod end.
Check the aileron travel which should be 20 degrees UP and 14 degrees DOWN, with tolerance of +/- 1 degree. Check for any angular discrepancy between the left and right sides, there should not be any.

The outboard ends of the ailerons have no specification for relationship to the wingtips, but an undamaged airplane will likley have approximately 1/2" of drop from the wingtip fairing trailing edge.

Speaking of flaps, how much play is allowable/avisable?

I do not recall ever reading a specification for flap "looseness" in the B model. Any "looseness" will be affected by the flap roller-to-track fitment. The track openings do have a max size of 0.6035" and the flap track may not be worn or dressed more than 10%.
I have commonly seen flaps that were considered airworthy have approximately 1/2" - 3/4" or so of movement at their trailing edge, although less is certainly better.

As stated above, and in the book, the aileron neutral is rigged in relation to the flap.

My question is this: Isn't an aileron truly at neutral when it is streamlined to the portion of the wing directly in front of it? I have never liked rigging ailerons to the flaps or wing tips, as either of those items could be off a little. Mismatch between two adjacent surfaces can be dealt with as a separate issue. Usually it is the wing tip which was not installed quite right.

I know we are talking only a fraction of an inch here, and a small deviation from neutral may never be noticed in flight, but I have always felt aileron neutral is its position relative to the wing.

Ron

The flap, by nature of it's track-installation, is rigged to streamline with the wing. (And in a perfect world is also steamlined with the fuselage shoulder-fairing, but this is a rare event in actuality.) While at rest gravity allows the flap to fall against it's lower track limits and that is why it must be raised to it's lifted position (the streamlined one it experiences in-flight due to air pressure) when rigging the airplane.
The ailerons do not share the same tendency to fall when at rest due to their relationship to the aileron sector and it's position being controlled by balanced cable tensions. That is why they do not need to be lifted during rigging (provided their cable tensions are properly set.)

I happened upon this same question a while back when adjusting the aileron push-pullrods during a wing rigging operation. The only other Cessnas I had for reference were newer (than 1950's) and their ailerons had a noticeable upsweep at the end to account for the wing washout. Those ailerons flushed nicely with both the flaps and the wingtips.

In my case, I just decided that as long as they were the same on both sides, it wasn't going to make a huge difference. I flushed them with the flaps, and the ailerons sit about 1/2" below the wingtip trailing edges. An airplane that formerly flew with a harsh right banking and left adverse yaw tendency(from out of rig wings AND ailerons) now flies nicely hands off.

I realize this thread is a month old, but someone will undoubtedly find their way here in the future with the same question.

I am at this point now. If anyone has an e-copy of the rigging proceedure for the 170, I could use a copy.

Thanks

George

Thanks for the input!

In the 170A IPC, Figure 5 , Item 18, Rod End appears as a NAS36. For the life of me , I cannot find that number listed anywhere or cross referenced to anything.
Does anyone have the correct number or cross ref. for those rod ends? I am in the process of rigging the ailerons, and would like to replace the worn\noisy ends while everything is accessible.

Rick

They've been superseded to S1106-3

http://www.cessnaparts.com/?s1=NAS36&s2 ... arch+Parts
Just under $40 a piece at Cessnaparts.com

McFarlane also has them.
http://mcfarlane-aviation.com/Products/ ... =MCS1106-3&
Just under $30 at McFarlane

Thank you very much Bruce, I'll get them ordered..and I'll know where to cross reference on the next one..

1SeventyZ wrote:I happened upon this same question a while back when adjusting the aileron push-pullrods during a wing rigging operation. The only other Cessnas I had for reference were newer (than 1950's) and their ailerons had a noticeable upsweep at the end to account for the wing washout. Those ailerons flushed nicely with both the flaps and the wingtips.

In my case, I just decided that as long as they were the same on both sides, it wasn't going to make a huge difference. I flushed them with the flaps, and the ailerons sit about 1/2" below the wingtip trailing edges. An airplane that formerly flew with a harsh right banking and left adverse yaw tendency(from out of rig wings AND ailerons) now flies nicely hands off.

I realize this thread is a month old, but someone will undoubtedly find their way here in the future with the same question.

It sounds as if your ailerons are correct. Ideally the flaps should be level with the shoulder fairings, the inboard ends of the ailerons level with the flaps, and the outboard ends of the ailerons 1/2" below the fairing trailing edge.