Preflight Ailerons Inspections

[MoonlightVFR]

What should a pilot be looking for in the Ailerons pre flight inspection?

What about a deeper inspection as in the Annual ?

Have parts ever departed?

I have never has any issues w ailerons on s.n. 26433 C170B, I guess I am just wondering.

Cessna 170 is just a very nice airplane.

[brian.olson]

Here is my personal routine for preflight. I am not qualified to perform an annual so others will need to chime in on that aspect.

1. Visually inspect exterior top and bottom for physical damage, any new deformation, paint scapes/corrosion;
2. Manually move aileron through full range of motion up/down. Feel for any binding, friction, squeaking;
3. Attempt to move aileron laterally (left/right). Shouldn't be any play;
4. Aileron "up". Inspect hinges for cracks. Inspect condition of bolts and nuts.
5. With flashlight, inspect aileron and wing root "holes" for physical issues (mice, wasps, debris);
6. Aileron "down". Inspect top of hinges for cracks. Inspection condition of bolt tops.
7. Inspect sides (left, right) of aileron for damage or deformation.
8. Inspect linkage. Grab with fingers and attempt to move. Should not be any play;
9. Sight along trailing edge for any deformation.

Looking forward to learning what other folks do so that I can add to my list ...

[Ryan Smith]

I’ll add to what Brian posted.

Three threads clear on the bottom of the nuts on the hinge bolts, I check the pushrod for security and condition, and I run a hand on the counterweight to ensure it isn’t damaged or coming loose.

[hilltop170]

Also, I rotate the push rod to make sure the rod end Heim joints are free and not bound up.

[bgiesbrecht]

In addition to the above, I actually slide my finger along the pushrod feeling for any irregularity. One of my CFIs at the flight school I used to go to told me this as she found a pretty significant crack in the pushrod of a 10 year old 172S this way.

[cessna170bdriver]

I visually check the shop heads on the rivets that hold the counterweights in place. I’ve found some missing in the past, apparently due to dissimilar metal corrosion between the lead and aluminum.

Also, I rotate the push rod to make sure the rod end Heim joints are free and not bound up.

I’ve always done this too, but since the rebuild I don’t get any rotation. The “feel” of the ailerons, either moving them directly, or with the yoke doesn’t seem any different, so I’m not too worried about it.

[wabuchanan]

[quote="cessna170bdriver"]I visually check the shop heads on the rivets that hold the counterweights in place. I’ve found some missing in the past, apparently due to dissimilar metal corrosion between the lead and aluminum.


I too have found the heads missing on my counterweights. I always run my fingers over them to make sure they are all there.

[GAHorn]

Here is my personal routine for preflight. I am not qualified to perform an annual so others will need to chime in on that aspect.

1. Visually inspect exterior top and bottom for physical damage, any new deformation, paint scapes/corrosion;
2. Manually move aileron through full range of motion up/down. Feel for any binding, friction, squeaking;
3. Attempt to move aileron laterally (left/right). Shouldn't be any play;
4. Aileron "up". Inspect hinges for cracks. Inspect condition of bolts and nuts.
5. With flashlight, inspect aileron and wing root "holes" for physical issues (mice, wasps, debris);
6. Aileron "down". Inspect top of hinges for cracks. Inspection condition of bolt tops.
7. Inspect sides (left, right) of aileron for damage or deformation.
8. Inspect linkage. Grab with fingers and attempt to move. Should not be any play;
9. Sight along trailing edge for any deformation.

Looking forward to learning what other folks do so that I can add to my list ...

As mentioned by others, rotate the HEIM (tie rod end) for freedom in rotation. (Miles, yours may be painted or needing lube) This is important because if the bearing does not rotate it will place undue stress upon the rod threaded section itself and can lead to a broken control rod, usually within that threaded portion. If in flight, this can lead to the loss of the airplane due to flutter.
When checking counterweights: Visually inspect for loose rivets where the lead weights are attached for corrosion, looseness, or any signs of bulging from corrosion or looseness from freezing during the winter. Snow/ice/water will run down from the wing, enter the area between the weights and freeze again at night. This can loosen the rivets and bulge the aileron-skin. Loosing a weight in flight can lead to flutter and complete loss of the airplane.
The B-model aileron trailing edge is actually NOT straight, but turned slightly UP towards the outboard ends. The ends of the aileron should be approximately 1/2" below the trailing edge of the original wingtip fairings when both ailerons are neutralized.
The aileron "throw" (Up and Down movement) should approximate 20-degrees UP and 15 DOWN. (the book says 20/14 plus/minus 1 degree)